Note: Descriptions are shown in the official language in which they were submitted.
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Description
BROADCAST RECEIVER AND METHOD OF PROCESSING DATA
Technical Field
Ill The present invention relates to a broadcast receiver, and more
particularly, to a telematics terminal capable of receiving broadcast data and
a
method for processing data.
Background Art
[2] Telematics is a compound word that stems from the terms
"telecommunication" and "informatics". Herein, telematics consists of a
blending of
diverse technologies including wireless telecommunication, computers,
internet, and
other multi-media industries.
Disclosure of Invention
[3] A telematics terminal may use a position measuring system and a
wireless telecommunications network, so as to provide traffic information,
guidance
instructions in case of emergency situations, remote vehicle diagnosis, and
internet
services to drivers and passengers of a vehicle.
According to an aspect of the present invention, there is provided a
broadcast receiver, comprising: a signal receiving unit for receiving a
broadcast
signal including mobile service data and main service data, wherein a Reed-
Solomon
(RS) frame includes at least one data packet corresponding to the mobile
broadcast
service data, an RS parity generated based upon the at least one data packet,
and a
Cyclic Redundancy Check (CRC) checksum generated based upon the mobile
service data and the RS parity; an RS frame decoder for performing CRC-
decoding
and RS-decoding on the RS frame, thereby correcting errors occurred in the
corresponding mobile service data; a decoding unit for decoding text
information
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included in the error-corrected mobile service data, and outputting the
decoded text
information; a text-to-speech (TTS) module for converting the outputted text
information to a voice signal; a voice output unit for outputting the
converted voice
signal; and a control unit for controlling the voice output unit.
According to another aspect of the present invention, there is provided
a method of processing data of a broadcast receiver, comprising: receiving a
broadcast signal including mobile service data and main service data, wherein
a
Reed-Solomon (RS) frame includes at least one data packet corresponding to the
mobile service data, an RS parity generated based upon the mobile service
data, and
a Cyclic Redundancy Check (CRC) checksum generated based upon the mobile
service data and the RS parity; performing CRC-decoding and RS-decoding on the
RS frame, thereby correcting errors occurred in the corresponding mobile
broadcast
service data; decoding text information included in the error-corrected mobile
service
data, and outputting the decoded text information; converting the outputted
text
information to a voice signal; and outputting the converted voice signal.
[4] Some embodiments are directed to a telematics terminal capable of
receiving broadcast data and a method for processing data.
[5] Some embodiments may provide a telematics terminal and a method
for processing data, wherein the telematics terminal is capable of receiving
mobile
broadcast services.
[6] Some embodiments may provide a telematics terminal and a method
for processing data, wherein the telematics terminal is capable of processing
text
data information received from the mobile broadcast service data to a voice
signal,
thereby outputting the processed voice signal.
[7] Additional advantages and features of some embodiments of the
invention will be set forth in part in the description which follows and in
part will
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become apparent to those having ordinary skill in the art upon examination of
the
following or may be learned from practice of the invention. The objectives and
other
advantages of some embodiments of the invention may be realized and attained
by
the structure particularly pointed out in the written description and claims
hereof as
well as the appended drawings.
[8] In another aspect, a broadcast receiver includes a signal receiving unit,
a RS frame decoder, a decoding unit, a text-to-speech (TTS) module, a voice
output
unit, and a control unit. The signal receiving unit receives broadcast signal
multiplexed mobile broadcast service data including text information and main
broadcast service data. The mobile broadcast service data configures a RS
frame.
The RS frame includes at least one data packet corresponding to the mobile
broadcast service data, an RS parity generated based upon the at least one
data
packet, and a CRC checksum generated based upon the at least one data packet
and the RS parity. The RS frame decoder performs CRC-decoding and RS-decoding
on the RS frame, thereby correcting errors occurred in the corresponding
mobile
broadcast service data. The decoding unit decodes the text information
included in
the error-corrected mobile broadcast service data, and outputs the decoded
text
information. The text-to-speech (TTS) module converts the outputted text
information
to a voice signal. The voice output unit outputs the converted voice signal.
The
control unit controls the voice output unit.
[9] In some embodiments, the broadcast receiver further includes a
position information module for searching and generating a current position
information of the broadcast receiver, and a telecommunication module for
communicating with a domestic carrier located at a remote site via a wireless
telecommunication network, and transmitting the current position information
to the
domestic carrier.
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[10] In some embodiments, the broadcast receiver further includes a
navigation unit for performing at least one of travel route search, map
matching, and
travel route guidance by using a map information and the current position
information.
[11] In some embodiments, the broadcast receiver further includes a known
sequence detector for detecting known data linearly inserted within at least
one data
group, which configures the RS frame, and a channel equalizer for channel-
equalizing the mobile broadcast service data using the detected known data.
[12] In some embodiments, the broadcast receiver further includes a
transmission parameter detector for detecting transmission parameters inserted
in a
predetermined position within at least one data group, which configures the RS
frame, and a power controller for controlling power based upon the detected
transmission parameters, thereby receiving a data group including requested
mobile
broadcast service data.
[13] In some embodiments, the broadcast receiver further includes a block
decoder for symbol-decoding the mobile broadcast service data in block units,
based
upon the detected transmission parameter.
[14] In some embodiments, the TTS module may include a language
processor, a voice database (DB), and a voice processor. The language
processor
analyzes and pre-processes the decoded text information. The voice database
(DB)
stores voice data being matched corresponding to the linguistic characters.
The
voice processor matches the pre-processed text information outputted from the
language processor with the voice data of the voice DB, thereby converting the
text
information to voice signals. The TTS module performs selectively the voice
conversion process according to control of the control unit.
[15] In some embodiments, the control unit controls output of the voice
signals converted by the TTS module based upon priority levels of the voice
signals
when an external event occurs.
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[16] In another aspect, a data processing method of a broadcast receiver
includes receiving broadcast signal multiplexed mobile broadcast service data
including text information ad main broadcast service data, wherein the mobile
broadcast service data configures a RS frame, and wherein the RS frame
includes at
5 least one data packet corresponding to the mobile broadcast service data, an
RS
parity generated based upon the at least one data packet, and a CRC checksum
generated based upon the at least one data packet and the RS parity,
performing
CRC-decoding and RS-decoding on the RS frame, thereby correcting errors
occurred
in the corresponding mobile broadcast service data, decoding the text
information
included in the error-corrected mobile broadcast service data, and outputting
the
decoded text information, converting the outputted text information to a voice
signal,
and outputting the converted voice signal.
[17] It is to be understood that both the foregoing general description and
the following detailed description of some embodiments of the present
invention are
exemplary and explanatory and are intended to provide further explanation of
the
invention as claimed.
[18] The telematics terminal capable of receiving broadcast data and the
method for processing data according to some embodiments may have the
following
advantages. More specifically, some embodiments of the telematics terminal
capable
of receiving broadcast data and the method for processing data may be robust
(or
strong) against any error that may occur when transmitting mobile broadcast
service
data through a channel. Some embodiments may be also highly compatible to the
conventional system. Moreover, some embodiments may also receive the mobile
broadcast service data without any error occurring, even in channels having
severe
ghost effect and noise. Additionally, by receiving a plurality of mobile
broadcast
services using diversity reception and processing the received mobile
broadcast
services, the signal reception strength may be enhanced in the mobile
broadcast
service receiving environment (or condition).
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[19] Furthermore, by inserting known data in a specific position within a data
region and by transmitting the processed data, the receiving performance of a
receiving system may be enhanced even in channel environments (or conditions)
undergoing frequent channel changes. Some embodiments may be even more
effective when applied to mobile and portable receivers, which are also liable
to
frequent change in channels, and which require strength (or robustness)
against
intense noise. Finally, by extracting text information from a received
broadcast
signal, and by converting the text information to a voice signal, some
embodiments
may enable the user to safely recognize the text information while driving.
Brief Description of the Drawings
[20] The accompanying drawings, which are included to provide a further
understanding of the invention and are incorporated in and constitute a part
of this
application, illustrate embodiment(s) of the invention and together with the
description
serve to explain the principle of the invention. In the drawings:
[21] FIG. 1 illustrates a conceptual block diagram showing a telematics
system according to an embodiment of the present invention;
[22] FIG. 2 illustrates a block diagram showing a structure of a telematics
terminal provided with a broadcasting module that can receive VSB mode mobile
broadcast services according to an embodiment of the present invention;
[23] FIG. 3 illustrates a block diagram showing a structure of a telematics
terminal provided with a broadcasting module according to an embodiment of the
present invention;
[24] FIG. 4 illustrates a detailed block diagram of a synchronization unit and
a mobile broadcast service data processor according to an embodiment of the
present invention;
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[25] FIG. 5 and FIG. 6 respectively illustrate a data group structure and data
configuration prior to and after data deinterleaving according to an
embodiment of the
present invention;
[26] FIG. 7 illustrates a block diagram of a TTS module according to an
embodiment of the present invention;
[27] FIG. 8 illustrates a flow chart showing process for processing data
according to an embodiment of the present invention;
[28] FIG. 9 illustrates an exemplary method of synthesizing voice signals in
the TTS module of FIG. 7;
[29] FIG. 10(a) illustrates an exemplary on-screen display for setting a TTS
function;
[30] FIG.10(b) illustrates an exemplary on-screen display for selectively
outputting voice signals;
[31] FIG. 11 illustrates a block diagram showing a structure of a telematics
terminal provided with a broadcasting module and a TTS module according to
another embodiment of the present invention;
[32] FIG. 12 illustrates a block diagram showing a structure of a telematics
terminal provided with a broadcasting module and a TTS module according to
another embodiment of the present invention;
[33] FIG. 13 illustrates a structure of a MPH frame for transmitting and
receiving mobile broadcast service data according to an embodiment of the
present
invention;
[34] FIG. 14 illustrates an exemplary structure of a VSB frame;
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[35] FIG. 15 illustrates a mapping example of the positions to which the first
4 slots of a sub-frame are assigned with respect to a VSB frame in a space
region;
[36] FIG. 16 illustrates a mapping example of the positions to which the first
4 slots of a sub-frame are assigned with respect to a VSB frame in a time
region;
[37] FIG. 17 illustrates an alignment of data after being data interleaved and
identified;
[38] FIG. 18 illustrates an enlarged portion of the data group shown in
FIG. 17 for a better understanding of the present invention;
[39] FIG. 19 illustrates an alignment of data before being data interleaved
and identified;
[40] FIG. 20 illustrates an enlarged portion of the data group shown in
FIG. 19 for a better understanding of the present invention;
[41] FIG. 21 illustrates an exemplary assignment order of data groups being
assigned to one of 5 sub-frames according to the present invention;
[42] FIG. 22 illustrates an example of multiple data groups of a single
parade being assigned (or allocated) to an MPH frame;
[43] FIG. 23 illustrates an example of transmitting 3 parades to an MPH
frame according to an embodiment of the present invention;
[44] FIG. 24 illustrates an example of expanding the assignment process of
3 parades to 5 sub-frames within an MPH frame;
[45] FIG. 25 illustrates a block diagram showing a general structure of a
digital broadcast transmitting system according to an embodiment of the
present
invention;
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[46] FIG. 26 illustrates a block diagram showing an example of a service
multiplexer;
[47] FIG. 27 illustrates a block diagram showing an example of a transmitter
according to an embodiment of the present invention;
[48] FIG. 28 illustrates a block diagram showing an example of a pre-
processor according to an embodiment of the present invention;
[49] FIG. 29 illustrates a conceptual block diagram of the MPH frame
encoder according to an embodiment of the present invention;
[50] FIG. 30 illustrates a detailed block diagram of an RS frame encoder
among a plurality of RS frame encoders within an MPH frame encoder;
[511 FIG. 31(a) and FIG. 31(b) illustrate a process of one or two RS frame
being divided into several portions, based upon an RS frame mode value, and a
process of each portion being assigned to a corresponding region within the
respective data group;
[52] FIG. 32(a) to FIG. 32(c) illustrate error correction encoding and error
detection encoding processes according to an embodiment of the present
invention;
[53] FIG. 33 illustrates an example of performing a row permutation (or
interleaving) process in super frame units according to an embodiment of the
present
invention;
[54] FIG. 34(a) and FIG. 34(b) illustrate an example of creating an RS frame
by grouping data, thereby performing error correction encoding and error
detection
encoding;
[55] FIG. 35(a) and FIG. 35(b) illustrate an exemplary process of dividing an
RS frame for configuring a data group according to an embodiment of the
present
invention;
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[56] FIG. 36 illustrates a block diagram of a block processor according to an
embodiment of the present invention;
[57] FIG. 37 illustrates a detailed block diagram of a convolution encoder of
the block processor of FIG. 36;
[58] FIG. 38 illustrates a symbol interleaver of the block processor of
FIG. 36;
[59] FIG. 39 illustrates a block diagram of a group formatter according to an
embodiment of the present invention;
[60] FIG. 40 illustrates a detailed diagram of one of 12 trellis encoders
included in the trellis encoding module of FIG. 27;
[61] FIG. 41 illustrates an example of assigning signalling information area
according to an embodiment of the present invention;
[62] FIG. 42 illustrates a detailed block diagram of a signaling encoder
according to an embodiment of the present invention;
[63] FIG. 43 illustrates an example of a syntax structure of TPC data
according to an embodiment of the present invention;
[64] FIG. 44 illustrates an example of power saving of in a receiver when
transmitting 3 parades to an MPH frame level according to an embodiment of the
present invention;
[65] FIG. 45 illustrates an example of a transmission scenario of the TPC
data and the FIC data level according to an embodiment of the present
invention;
[66] FIG. 46 illustrates an example of a training sequence at the byte level
according to an embodiment of the present invention; and
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[67] FIG. 47 illustrates an example of a training sequence at the symbol
according to an embodiment of the present invention.
Best Mode for Carrying Out the Invention
[68] Reference will now be made in detail to the preferred embodiments of
the present invention, examples of which are illustrated in the accompanying
drawings. Wherever possible, the same reference numbers will be used
throughout
the drawings to refer to the same or like parts. In addition, although the
terms used in
the present invention are
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selected from generally known and used terms, some of the terms mentioned in
the de-
scription of the present invention have been selected by the applicant at his
or her di
scretion, the detailed meanings of which are described in relevant parts of
the de-
scription herein. Furthermore, it is required that the present invention is
understood,
not simply by the actual terms used but by the meaning of each term lying
within.
[69] Among the terms used in the present invention, mobile broadcast service
data
correspond to data being transmitted through a broadcasting network. Herein,
the
mobile broadcast service data may include at least one of mobile broadcast
service
data, pedestrian broadcast service data, and handheld broadcast service data,
and are
collectively referred to as mobile broadcast service data for simplicity.
Herein, the
mobile broadcast service data not only correspond to
mobile/pedestrian/handheld
broadcast service data (M/P/H broadcast service data) but may also include any
type of
broadcast service data with mobile or portable characteristics. Therefore, the
mobile
broadcast service data according to the present invention are not limited only
to the M/
P/H broadcast service data.
[70] The above-described mobile broadcast service data may correspond to data
having information, such as program execution files, stock information,
weather
forecast information, traffic information, and so on, and may also correspond
to AN
data, such as TV series or movies. Finally, the mobile broadcast service data
may also
correspond to audio-specific data, such as music programs. Also, the mobile
broadcast
service data may include weather forecast services, traffic information
services, stock
information services, viewer participation quiz programs, real-time polls and
surveys,
interactive education broadcast programs, gaming services, services providing
in-
formation on synopsis, character, background music, and filming sites of soap
operas
or series, services providing information on past match scores and player
profiles and
achievements, and services providing information on product information and
programs classified by service, medium, time, and theme enabling purchase
orders to
be processed. Herein, the present invention is not limited only to the
services
mentioned above.
[71] Among the terms used in the description of the present invention, main
broadcast
service data correspond to data that can be received by a fixed receiving
system and
may include audio/video (A/V) data. More specifically, the main broadcast
service
data may include AN data of high definition (HD) or standard definition (SD)
levels
and may also include diverse data types required for data broadcasting. Also,
the
known data correspond to data pre-known in accordance with a pre-arranged
agreement between the receiving system and the transmitting system.
[72] The present invention relates to enabling a telematics terminal to
receive and
process mobile broadcast services. Most particularly, the present invention
relates to
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enabling a telematics terminal to receive and process vestigial side band
(VSB) mode
mobile broadcast service data.
[73] Also, the present invention provides a telematics terminal that receives
mobile
broadcast service data including text data (or short message data), extracts
the text data
from the mobile broadcast service data, thereby outputting the extracted text
data to a
display unit or converting (or synthesizing) the text data to a voice signal
and
outputting the converted voice signal. More specifically, a telematics
terminal
equipped in a vehicle may receive mobile broadcast service data including text
data
and extract the text data from the mobile broadcast service data. Then, the
telematics
terminal may output the extracted text in the form of a text message on the
display
screen. However, if the text data is outputted visually, the user may have
difficulty in
viewing the actual text data, which may eventually be hazardous when the user
is
driving the vehicle. Therefore, the telematics terminal capable of receiving
broadcast
data according to the present invention may convert the text data to an
audible voice
signal, thereby outputting the converted voice signal.
[74] The telematics terminals are largely provided for before-market usage and
for
after-market usage. The before-market telematics terminals are provided in man-
ufactured vehicles as an optional feature. Users may also purchase after-
market
telematics terminals and personally equipped their vehicles with the purchased
terminal. More specifically, after-market telematics terminals may largely
include
fixed-type telematics terminals and mobile-type telematics terminals. Fixed-
type
terminals are permanently fixed once equipped inside a vehicle and cannot be
removed. On the other hand, mobile-type telematics terminals may be detachably
fixed
inside a vehicle. The telematics terminal according to the present invention
may be
applied to both the before-market and after-market telematics terminals. Also,
in the
description of the present invention, a driver or passenger using the
telematics services
within a vehicle will be referred to as a "user" for simplicity.
[75]
[76] Telematics System
[77] FIG. 1 illustrates a conceptual block diagram showing a telematics system
according to an embodiment of the present invention. Referring to FIG. 1, the
telematics system broadly includes a broadcasting station, a domestic carrier,
a vehicle
information center, a global positioning system (GPS), and a telematics
terminal. More
specifically, the broadcasting station transmits mobile broadcast service data
via a
broadcasting network. The domestic carrier transmits and receives information
to and
from the telematics terminal via a wireless telecommunication network. The
vehicle in-
formation center collects and provides traffic (or vehicle) information to the
broadcasting station and/or the domestic carrier. The GPS provides position in-
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formation of specific vehicles. And, the telematics terminal provides
safety/security
services, telecommunication services, broadcast services, navigation services,
and so
on. For example, the vehicle information center collects diverse traffic
information via
a variety of paths (e.g., input from operator (or manager), other servers
passing through
the network, or probe cars) and, then, provides the collected information to
the
broadcasting station and/or the domestic carrier.
[78] More specifically, referring to FIG. 1, the telematics terminal may
provide
diverse types of services including traffic information services, emergency
rescue
services, remote diagnosis/control services, stolen vehicle tracking services,
wireless
internet services (e.g., finance update, news update, e-mail, messenger, Vol)
services),
2-dimensional/3-dimensional (2D/3D) navigation services, personal information/
convenience services, phone call services, and so on, to the user using
technologies
based on position measurement system, wireless telecommunication network, and
voice recognition. Also, the telematics terminal may read (or play-back or
reproduce)
or write (or record) audio signals and video signals stored in various
write/read (or
record/reproduce) media, such as a cassette tape, CD, DVD, MP3, and so on,
through a
write/read media driver.
[79] Furthermore, the telematics terminal may receive and output mobile
broadcast
service data being transmitted via the broadcasting network. Particularly, the
telematics
terminal may simultaneously receive diverse types of mobile broadcast service
data
being transmitted in a VSB mode, which are then demodulated and decoded,
thereby
simultaneously outputted. The plurality of mobile broadcast services being
outputted to
the output device may be sent to the user in the form of at least one of text,
voice,
graphic, still image, and moving image.
[80] For example, when it assumed that the plurality of mobile broadcast
services
selected by the user corresponds to TV series and traffic information, the
telematics
terminal simultaneously receives the TV series information and traffic
information,
which are then demodulated and decoded. Thereafter, the telematics terminal
may
display the selected TV series on one portion of a screen and display the
traffic in-
formation on another portion of the screen. In another example, the telematics
terminal
may display the TV series on the screen and provide the traffic information in
the form
of subtitles or audio data.
[81] Furthermore, the present invention may convert the received text data to
a voice
signal, thereby outputting the converted voice signal.
[82] When the broadcasting station transmits the mobile broadcast service data
in
VSB mode, additional encoding may be performed on the mobile broadcast service
data. Subsequently, the additionally encoded mobile broadcast service data may
be
multiplexed with the main broadcast service data in a parade structure and,
then,
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transmitted. The additional encoding process may include at least one of block
encoding at a coding rate of 1/H (wherein H is an integer and ), error
correction
encoding, error detection encoding, row permutation processes. Thus, the
mobile
broadcast service data may be provided with more robustness (or strength),
thereby
being capable of responding more effectively to noise and channel environment
that
undergoes frequent changes.
[83] More specifically, each parade is repeated per parade identifier (e.g.,
parade-id)
to transmit the same mobile broadcast service. At this time, this transmission
path will
be referred to as a parade in the present invention. In other words, one or
more parades
are temporally multiplexed in one physical channel determined by frequency.
[84] For example, mobile broadcast service 1 and mobile broadcast service 2
can be
transmitted from parade alpha, mobile broadcast service 3 and mobile broadcast
service 4 can be transmitted from parade beta, and mobile broadcast service 5
can be
transmitted from parade gamma.
[85] At this time, one parade may transmit either one RS frame or two RS
frames, i.e.,
a primary RS frame and a secondary RS frame.
[86] At this point, when data included in one RS frame assign into a plurality
of data
groups and the data groups are transmitted to the receiving system. Herein,
one data
group may consist of a plurality of mobile broadcast service data packets,
wherein one
mobile broadcast service data packet includes a plurality of mobile broadcast
service
data bytes. Furthermore, the data group may be divided into a plurality of
regions
based upon a degree of interference from the main broadcast service data. At
this point,
a long known data sequence may be periodically inserted in a region that has
no in-
terference from the main broadcast service data.
[87] Also, according to an embodiment of the present invention, each parade
may
transmit different types of mobile broadcast service data. For example, a
parade alpha
may transmit TV series, and a parade beta may transmit traffic information.
[88] Furthermore, according to the embodiment of the present invention, a
plurality of
data groups may co-exist with main broadcast service data packet in the parade
section,
and only main broadcast service data may exist in section between parade and
parade.
[89] At this point, when the telematics terminal receives only mobile
broadcast
service data including traffic information, the telematics terminal may turn
the power
on only during a slot to which the data group of the parade, which transmits
the mobile
broadcast service data, is assigned, and the telematics terminal may turn the
power off
during the remaining slots, thereby reducing power consumption of the
telematics
terminal.
[90] Meanwhile, in order to extract (or receive) and decode the mobile
broadcast
service data, the telematics terminal requires system information. Such system
in-
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formation may also be referred to as service information. The system
information may
include channel information, event information, and so on.
[91] The telematics terminal according to the present invention may receive
system
information, which provides detailed information on the mobile broadcast
service data
including the map information or traffic information. For example, the
telematics
terminal may receive system information associated with the channel
transmitting map
information or traffic information, or system information associated with the
time
during which map information or traffic information is transmitted.
[92] The system information may include channel information, event
information, etc.
In the embodiment of the present invention, the PSI/PSIP tables are applied as
the
system information. However, the present invention is not limited to the
example set
forth herein. More specifically, regardless of the name, any protocol
transmitting
system information in a table format may be applied in the present invention.
The PSI
table is an MPEG-2 system standard defined for identifying the channels and
the
programs. The PSIP table is an advanced television systems committee (ATSC)
standard that can identify the channels and the programs. The PSI table may
include a
program association table (PAT), a conditional access table (CAT), a program
map
table (PMT), and a network information table (NIT).
[93] Herein, the PAT corresponds to special information that is transmitted by
a data
packet having a PID of '0'. The PAT transmits PID information of the PMT and
PID
information of the NIT corresponding to each program. The CAT transmits in-
formation on a paid broadcasting system used by the transmitting system. The
PMT
transmits PID information of a transport stream (TS) packet, in which program
iden-
tification numbers and individual bit sequences of video and audio data
configuring the
corresponding program are transmitted, and the PID information, in which PCR
is
transmitted. The NIT transmits information of the actual transmission network.
[94] The PSIP table may include a virtual channel table (VCT), a system time
table
(STT), a rating region table (RRT), an extended text table (ETT), a direct
channel
change table (DCCT), an event information table (EIT), and a master guide
table
(MGT). The VCT transmits information on virtual channels, such as channel in-
formation for selecting channels and information such as packet identification
(PID)
numbers for receiving the audio and/or video data. More specifically, when the
VCT is
parsed, the PID of the audio/video data of the broadcast program may be known.
Herein, the corresponding audio/video data are transmitted within the channel
along
with the channel name and channel number. The STT transmits information on the
current data and timing information. The RRT transmits information on region
and
consultation organs for program ratings. The ETT transmits additional
description of a
specific channel and broadcast program. The EIT transmits information on
virtual
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channel events (e.g., program title, program start time, etc.). The
DCCT/DCCSCT
transmits information associated with automatic (or direct) channel change.
And, the
MGT transmits the versions and PID information of the above-mentioned tables
included in the PSIP.
[95] Also, the basic unit of each table within the PSI/PSIP consists of a
section unit.
Herein, at least one section is combined to form a table. For example, the VCT
may be
divided into 256 sections. In this example, one section may hold a plurality
of virtual
channel information. However, each information on one virtual channel cannot
be
divided into 2 or more sections. Furthermore, a TS packet holding the mobile
broadcast service data may correspond to either a packetized elementary stream
(PES)
type or a section type. More specifically, PES type mobile broadcast service
data are
configured of TS packets, or section type mobile broadcast service data are
configured
of TS packets. The broadcasting station according to an embodiment of the
present
invention transmits mobile broadcast service data in the forms of text,
graphic, and still
image as the section type mobile broadcast service data. Alternatively, the
broadcasting station transmits mobile broadcast service data in the forms of
audio or
moving picture as the PES type mobile broadcast service data.
[96] In the present invention, the section type mobile broadcast service data
are
included in a digital storage media-command and control (DSM-CC) section.
Herein,
according to the embodiment of the present invention, the DSM-CC section is
configured of 188-byte unit TS packets. Furthermore, the packet identification
(or
identifier) of the TS packet configuring the DSM-CC section is included in a
data
service table (DST). When transmitting the DST, `0x95' is assigned as the
value of a
stream-type field included in the service location descriptor of the PMT or
the VCT.
More specifically, when the PMT or VCT stream_type field value is `0x95', the
telematics system may acknowledge that mobile broadcast service data are being
received. At this point, the mobile broadcast service data may be transmitted
by a data
carousel method. The data carousel method corresponds to repeatedly
transmitting
identical data on a regular basis.
[97] The telematics terminal may only use the tables included in the PSI, or
only use
the tables included in the PSIP, or use a combination of the table included in
the PSI
and PSIP, so as to parse and decode the mobile broadcast service data that are
being
transmitted. In order to parse and decode the mobile broadcast service data,
in case of
the PSI, at least the PAT and PMT are required, and in case of the PSIP, the
VCT is
required. For example, the PAT may include system information transmitting the
mobile broadcast service data and a PID of the PMT corresponding to the mobile
broadcast service data (or program number). Also, the PMT may include a PID of
a TS
packet transmitting the mobile broadcast service data. Furthermore, the VCT
may
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include information on the virtual channel transmitting the mobile broadcast
service
data and a PID of the TS packet transmitting the mobile broadcast service
data.
[98]
[99] Telematics Terminal
[100] FIG. 2 illustrates a block diagram showing a structure of a telematics
terminal
according to an embodiment of the present invention, wherein the telematics
terminal
is provided with a broadcasting module that is capable of receiving VSB mode
mobile
broadcast service data. Referring to FIG. 2, the telematics terminal includes
a control
unit (or central process unit (CPU)) 100. Herein, the telematics terminal also
includes a
position information module 101, a telecommunication module 102, a
broadcasting
module 103, a write/read media driver 104, an outer interface unit 105, a user
input
unit 106, a vehicle network unit 107, a navigation unit 108, a voice
processing unit
109, a display unit 110, a memory 111, and a text-to-speech (TTS) module 112.
The
control unit 100 controls the overall operation of the telematics terminal and
may also
include a memory (e.g., RAM, ROM, etc.) for storing diverse information
required for
the basic control of the telematics terminal. Also, examples for of the
control unit 100
controlling the TTS functions will be described in detail later on with
reference to FIG.
3.
[101] The position information module 101 may include at least one of or both
a GPS
receiver (not shown) and a bearing sensor (not shown). Herein, the GPS
receiver
receives a current position information from a satellite GPS at a
predetermined cycle
period (e.g., a cycle period of 0.5 second). The bearing sensor receives
position in-
formation provided from the vehicle. For example, the position information
module
101 mainly receives the position information from the GPS receiver. However,
in
situations where the GPS receiver does not operate, the position information
module
101 may also use the bearing sensor. The bearing sensor receives signals from
at least
any one of an angle sensor, a terrestrial magnetic field sensor, and a vehicle
speed
sensor, thereby calculating a position of the vehicle based upon the received
signals.
[102] Hereinafter, in the description of the present invention, the position
information
module 101 will include the GPS receiver and the bearing sensor for
simplicity.
According to the embodiment of the present invention, the position information
module 101 corresponds to a hybrid-type position information module, which
extracts
GPS information and compensation data for compensating the position of a
moving
vehicle using a variety of sensors equipped in the vehicle. Then, the position
in-
formation module 101 uses the extracted compensation data so as to compensate
the
position of the moving vehicle, thereby locating the current position of the
cor-
responding vehicle. As described above, the position information module 101
may use
both types of information. Yet, in some cases, the position information module
101
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may only use the GPS information in order to acquire (or obtain) the desired
position
information. The current position information of the corresponding vehicle
generated
from the position information module 101 is then provided to the control unit
100.
[1031 In searching for a path depending upon a user input, the
telecommunication
module 102 may receive traffic information for setting up the shortest
distance from
the current position to the final destination. Alternatively, the
telecommunication
module 102 may also receive information either via communication among
vehicles or
via transmitters of a separate information center and/or roadside
transmitters. The
telecommunication module 102 may communicate with a digital interface that
includes, for example, at least one of wireless application protocol (WAP),
code
division multiple access (CDMA) evolution-data only (1xEV-DO), wireless local
area
network (LAN), dedicated short range communication (DSRC), 802.16, mobile
internet, wireless broadband internet (WiBro), world interoperability for
microwave
access (WiMAX), high speed downlink packet access (HSDPA), and so on. However,
whenever required, the telecommunication module 102 may not be provided with a
telematics terminal.
[1041 Also, depending upon a user request (e.g., vehicle theft report), the
domestic
carrier may request the current position of the stolen vehicle via a wireless
telecom-
munication network to the telecommunication module 102. In this case, the
telecom-
munication module 102 receives the current position information of the
corresponding
vehicle, which is generated from the position information module 101, through
the
control unit 100. Thereafter, the telecommunication module 102 transmits the
received
position information to the domestic carrier. Alternatively, the telematics
terminal may
detect the vehicle theft incident, thereby automatically sending the current
position in-
formation of the stolen vehicle to the domestic carrier via the
telecommunication
module 102. In this case, the domestic carrier may transmit the received
position in-
formation of the stolen vehicle to the user or to government offices, such as
a police
office (or station).
[1051 The broadcasting module 103 receives mobile broadcast service data
transmitted
in VSB mode. Herein, the mobile broadcast service data include text data.
Then, the
broadcasting module 103 demodulates and decodes the received mobile broadcast
service data, thereby outputting the processed data to an output device. The
output
device includes a display unit 110, a voice output unit 109, and so on. The
broadcasting module 103 according to the present invention may convert the
text data
extracted from the mobile broadcast service data to a voice signal, thereby
outputting
the converted voice signal to the voice output unit 109.
[1061 The process of the broadcasting module 103 receiving at least one set of
mobile
broadcast service data transmitted in VSB mode, which is then demodulated and
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decoded, will be described in detail in a later process. Additionally, the
broadcasting
module 103 may receive digital multimedia broadcasting (DMB) mode and digital
video broadcasting-handheld (DVB-H) mode broadcast service data, and the
broadcasting module 103 may also receive FM or AM radio broadcast programs.
For
example, the broadcasting module 103 responds to a radio-on signal of a
specific
channel provided from the user input unit 106, so as to receive and process
the radio
signal of the corresponding channel. Subsequently, the processed radio signal
passes
through the control unit 100 and is outputted through the speaker.
[107] According to an embodiment of the present invention, the broadcasting
module
103 receives and processes VSB mode mobile broadcast services. If the mobile
broadcast service data received, demodulated, and decoded from the
broadcasting
module 103 correspond to AN data, the corresponding mobile broadcast service
data
pass through the control unit 100 and are outputted to the display unit 110
and the
voice output unit 109. If the mobile broadcast service data correspond to
audio-specific
data, then the corresponding mobile broadcast service data may be outputted
only to
the voice output unit 109. However, if the mobile broadcast service data
correspond to
text or graphic data, then the corresponding mobile broadcast service data may
be
outputted only to the display unit 110. Also, according to the present
invention, in case
the text data are converted to a voice signal, the converted voice signal may
be
outputted to the voice output unit 109.
[108] The TTS module 112 converts diverse text data (data in the form of text
or short
message) of the terminal to audible voice messages. For example, text data,
such as
weather forecast, stock information, traffic information, news update, and so
on, are
converted to voice signals, which are outputted to the voice output unit 109.
Herein,
the text data that are being received may be filtered and outputted as voice
signals.
And, when an audio output event occurs other than the output of a TTS voice
signal, a
priority level is given to each voice signal, thereby determining the order of
output or
whether or not to output the voice signal. Also, the function of converting
text data to
voice signals of the TTS module may be set manually. However, if when the
telematics
terminal is in a predetermined condition, the TTS function may be set
automatically.
[109] Furthermore, the broadcasting module 103 may be provided with a
plurality of
broadcast receivers. And, herein, at least one of the broadcast receivers may
be set as a
broadcast receiver specified for receiving text data only. Then, the
broadcasting
module 103 continuously receives mobile broadcast service data including text
data
through a designated broadcast receiver. And, the TTS module 112 may convert
the
text data that are continuously being received into voice signals, thereby
outputting the
converted voice signals. At this point, when the broadcasting module 103 is
provided
with a plurality of broadcast receivers, a number of synchronization units
equivalent to
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the number of broadcast receivers may be further included. Also, a mobile
broadcast
service data processing unit, which is included in the broadcast receiver
specified for
receiving text data only, may independently process the mobile broadcast
service data
including text data. Moreover, the mobile broadcast service data that are
received by
the plurality of broadcast receivers may be processed by a single mobile
broadcast
service data processing unit. The broadcasting module 103 and the TTS module
112
will be described in more detail with reference to FIG. 3 and FIG. 7,
respectively.
[110] Referring to FIG. 3, the broadcasting module will now be described in
detail. The
position information module 101, the telecommunication 102, and the
broadcasting
module 103 either respectively receive or transmit the corresponding
information
through an antenna (not shown). At this point, the telematics terminal may be
provided
with an antenna for each of the position information module 101, the telecom-
munication 102, and the broadcasting module 103. Alternatively, the telematics
to
rminal may also be provided with multiple antennas supporting a plurality of
frequency
bands.
[111] The write/read media driver 104 may read (or play-back or reproduce)
audio
signals and video signals stored in various write/read (or record/reproduce)
media,
such as a cassette tape, CD, DVD, MP3, and so on. Alternatively, if a medium
inserted
in the write/read media driver 104 corresponds to a writable (or recordable)
medium,
such as CD-RW, the write/read media driver 104 may also record the mobile
broadcast
service data being received through the broadcasting module 103. In this case,
also, if
the data played-back by the write/read media driver 104 correspond to AN data,
the
corresponding data pass through the control unit 100 and are outputted to the
display
unit 110 and the voice output unit 109. If the played-back data correspond to
audio-
specific data, then the corresponding data may be outputted only to the voice
output
unit 109. However, if the played-back data correspond to text or image data,
then the
corresponding data may be outputted only to the display unit 110. Also, the
present
invention may convert the text data included in the mobile broadcast service
data to
voice signals, thereby outputting the converted voice signals to the voice
output unit
109.
[112] The outer interface unit 105 is used to interface an external device
with the
control unit 100. Herein, the external device may include a mobile storage
device,
iPOD, Bluetooth. The mobile storage device may include a flash memory, a USB
memory, a hard disk drive (HDD). For example, when using the bluetooth
technology,
a system including a wireless device control and terminal equipped within a
vehicle
may be remotely controlled. The user input unit 106 is an input device for
transmitting
a user command to the control unit 100. For example, the user input unit 106
corresponds to a button or key equipped on the telematics terminal or a remote
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controller. Also, a microphone, which is connected to the voice processing
unit 109,
and the display unit 110 are also included in the user input unit 106. At this
point, the
display unit 110 may be interfaced with the user in the form of a touch
screen.
[1131 More specifically, when operating the device, the user may use at least
one of the
methods for generating a control signal, such as the touch screen, the button
(or key),
the remote controller, and the microphone. Also, since the environment of the
vehicle
is prone to dangerous circumstances, a method enabling the user to avoid
operating the
device while driving the vehicle may be proposed. In order to do so, the
device may be
operated by voice control, and, accordingly, the user may be provided with
services via
audio (or voice) messages. Thus, a safer environment while driving may be
provided.
For example, when an e-mail service is requested, it would be extremely
convenient to
be able to provide information on the contents of an e-mail or information on
the
sender. Also, the voice controlled device may ensure safer than when operating
the
device by hand.
[1141 The display unit 110 may display a main screen so as to enable the user
to select
the operation of the device or a specific function based upon the control of
the control
unit 100. The user may select a specific element of the menu screen by using a
button
(or key) on the telematics terminal or a remote controller. The user may also
make a
selection by touching the corresponding element from the touch screen. More
specifically, the user may select a wanted (or requested) mobile broadcast
service via
the touch screen. Also, by touching the touch screen, the user may enable the
audio or
video file, which is pre-stored in the write/read media driver, to be played-
back. By
touching the touch screen, the user may also view the wanted (or requested)
mobile
broadcast service. Furthermore, the user may also use a navigation device,
such as a
global positioning system (GPS), so as to select any one of a route guidance
system,
which provides road (or travel route) guidance to the user from a current
position to the
wanted destination.
[1151 The voice processing unit 109 processes voice guidance data respective
of the
route search processed by the navigation unit 108 and outputs the processed
data to the
speaker. Alternatively, the voice processing unit 109 processes a voice (or
audio)
signal inputted through the telecommunication module 102 and outputs the
processed
signal to the speaker. Also, the voice processing unit 109 analyzes the voice
of the
user, which is inputted through the microphone, and provides the analyzed
result to the
control unit 100. For example, if the inputted voice signal corresponds to a
device
operation command, the control unit 100 operates the corresponding device.
And, if
the inputted voice signal corresponds to the data that are to be transmitted
to a remote
site through a wireless telecommunication network, the voice signal is
outputted to the
telecommunication module 102. At this point, since the voice signal can be
transmitted
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and received in two ways (or bi-directionally) through the wireless
telecommunication
network, a handsfree function can be embodied by using the speaker and
microphone,
which are already provided herein, without having to equip a separate
handsfree kit.
[116] The display unit 110 corresponds to a screen for displaying images and
may
consist of a liquid crystal display (LCD) device, a plasma display device, an
organic
EL display device, and so on. A head-up display (HUD) technology, which
displays
holographic images onto the windshield placed in front of the driver, may be
applied to
the display unit 110. The vehicle network unit 107 performs data and control
com-
munication between the telematics terminal and other devices equipped in the
vehicle.
And, depending upon the usage, a serial data bus, such as a controller area
network
(CAN), a media oriented systems transport (MOST), and an IDB-1394, is used in
the
vehicle network unit 107. More specifically, a network technology for vehicles
may
broadly include a network technology for multimedia and a network technology
for
electronic devices. Herein, the network technology for multimedia controls
multimedia
devices, such as audio devices, video devices, navigation devices, and gaming
devices.
And, the network technology for electronic devices controls essential vehicle
body
parts, such as the engine and handbrake. For example, the CAN may be used in
the
network technology for electronic devices, and the MOST and the IDB-1394 may
be
used in the network technology for multimedia.
[117] The navigation unit 108 controls the storage unit 111, which stores
travel route
search, map matching, travel route guidance, and map information. The
navigation unit
108 receives map information via the telecommunication module 102 or the
broadcasting module 103, thereby newly storing the received map information to
the
storage unit 111 or upgrading (or updating) the pre-stored map information.
The map
information received from the broadcasting module 103 and stored may be used
when
being matched with the current position of the telematics terminal and then
displayed,
or when a travel route from the current position to an inputted destination is
being
provided during a travel route search process based upon the user's input.
[118] For example, when the user selects a travel route search function, the
current
position information of the corresponding vehicle, which is generated from the
position
information module 101, passes through the control unit 100 so as to be
transmitted to
the navigation unit 108.
[119] Accordingly, the navigation unit 108 extracts map information, which is
to be
matched with the position information received from the position information
module
101, and GIS information from the map storage unit 111. Then, the navigation
unit 108
matches the extracted information with the received position information,
thereby
indicating the current position within the map displayed on the display unit
110. Ad-
ditionally, the navigation unit 108 may also output a route guidance broadcast
(or
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message) or a warning broadcast (or message) in the form of a voice message
through
the speaker. Herein, the route guidance message corresponds to a response to a
movement direction of the vehicle. Also, the navigation unit 108 may announce
the
warning message in order to notify or warn the driver that the vehicle is
nearing an in-
tersection (or crossroad) or a bottleneck section.
[1201 When the position information module 101 receives a user input
information
(e.g., a request for a route search of a specific destination or point of
interest (POI))
through the user input unit 106, the position information module 101 receives
the
position information of the specific destination or point of interest based
upon the
current position information. Thereafter, the position information module 101
may
send the received information to the navigation unit 108. The navigation unit
108 then
receives the position information of the current telematics terminal and the
route in-
formation from the current position to the requested destination from the
position in-
formation module 101. Subsequently, the navigation unit 108 extracts map
information
stored in the map storage unit 111, thereby matching the received position
information
with the extracted map information.
[1211 When the user inputs information on the requested destination, the
navigation
unit 108 searches for a travel route from its current position to the
requested
destination using the position information module 101. Then, the navigation
unit 108
displays the searched travel route or an optimum route on the display unit
110. More
specifically, the telematics terminal searches for all possible travel routes
from the
current position to the requested destination, thereby providing guidance
information
to the user of the route having the shortest travel time. However, in some
cases, the
navigation unit 108 may also provide the user with the optimum travel route or
a travel
route also indicating toll roads (or expressways). Herein, the travel route
may be
searched directly by the telematics terminal itself.
[1221 Alternatively, the optimum travel routes or detour travel routes
reflecting road
congestion information may be provided by receiving traffic information from
an
external source using the telecommunication module 102 or the broadcasting
module
103. Additionally, by reflecting the real-time traffic information, the
navigation unit
108 may also automatically search for another travel route with better road
conditions
and provide the newly searched travel route to the user, even while the
previous travel
guidance information is being provided to the user. In addition to the route
guidance
information, the navigation unit 108 may also provide the user with
information on
traffic conditions, accidents, emergency conditions or disasters.
[1231 Herein, traffic (or road) condition information may be constantly
changed (or
updated) due to accidents or construction. Therefore, such map information or
traffic
information is required to be updated in real-time. When using the related art
method
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of downloading traffic (or road) condition information from an external
storage device,
real-time traffic (or road) condition information cannot be applied to the
telematics
device. Therefore, the telematics terminal according to the present invention
receives
real-time map information or traffic information from the broadcasting module,
which
are then outputted to the navigation unit 108. Subsequently, the telematics
terminal
uses the real-time map information or traffic information so as to search for
the
requested travel route.
[124] FIG. 3 illustrates a block diagram showing a structure of a telematics
terminal
provided with a broadcasting module according to a first embodiment of the
present
invention, wherein the broadcasting module can receive text information from
VSB
mode mobile broadcast service data and store the received text information,
thereby
using the stored text information.
[125] More specifically, referring to FIG. 3, the broadcasting module 103
includes a
signal receiving unit 211, a synchronization unit 213, a mobile broadcast
service data
processing unit 215, a demultiplexer 216, an audio/video (A/V) decoder 217, a
data
decoder 218, a program specific information/program and system information
protocol
(PSUPSIP) information storage unit 219, an application controller 220, a data
storage
unit 221, and a flash memory 222. Based upon the control of the application
controller
220 or the outer interface unit 105, the flash memory 222 either stores or
reads the data
stored therein. Herein, the flash memory 222 may correspond to a non-volatile
memory. According to the present invention, other types of non-volatile memory
may
be used instead of the flash memory 222.
[126] Apart from the broadcasting module 103, the elements and operation of
the
telematics terminal shown in FIG. 3 are identical to those of the telematics
terminal
shown in FIG. 2. Therefore, detailed description of the same will be omitted
for
simplicity. Also, the TTS module 112 will also be described in more detail
with
reference to FIG. 7 and FIG. 9.
[127] The signal receiving unit 211 receives the mobile broadcast service data
including text data. The signal receiving unit 211 may also receive service
information,
such as PSI/PSIP information, which includes information on the mobile
broadcast
service data including the text data. The signal receiving unit 211 includes a
tuner.
Herein, the tuner tunes a frequency of a particular channel and down-converts
the
tuned frequency to an intermediate frequency (IF) signal. Then, the IF signal
of the
tuner is outputted to the synchronization unit 213. At this point, the text
data according
to the present invention may be multiplexed with the broadcast service data,
thereby
being received via the same channel. Alternatively, the text data may be
separately
received via another channel.
[128] The signal receiving unit 211 is controlled by the channel manager
included in
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the application controller 220. Also, the result and strength of the broadcast
signals
corresponding to each tuned channel are reported to the channel manager.
Herein, the
data received by the frequency of the specific channel may include mobile
broadcast
service data, main broadcast service data, and table data for decoding the
mobile
broadcast service data and the main broadcast service data. The mobile
broadcast
service data include the text data. Examples of the text data may include news
in-
formation data, weather information data, traffic information data, and stock
in-
formation data.
[1291 At this point, the traffic information includes all information on the
traffic
conditions (or road conditions) including traffic condition updates (or
information),
which is constantly updated and changed in real-time. Examples of the traffic
in-
formation include congestion and travel time information (CTT), point of
interest
(POI), safety driving information (SDI), road event information (REI), news in-
formation (NWS), traffic status image information (TSI), and so on. For
example,
when the telematics terminal receives information that traffic congestion in a
particular
area is becoming heavier, the navigation unit 108 may perform a new travel
route
search excluding the corresponding area with heavy traffic. Such conditions
are
synthesized to voice signals, which are outputted to inform the user (or
driver). Also,
when the telematics terminal receives information that road conditions in a
particular
area is becoming hazardous due to a construction process, the navigation unit
108 may
perform a new travel route search excluding the area under construction. Such
conditions are also synthesized to voice signals, which are outputted to
inform the user
(or driver).
[1301 In other words, the telematics terminal may receive information on
traffic
conditions, which are then used for travel route search or outputted along
with the
route guidance information of the navigation unit, so that the user can be
informed and
aware of such updated information. As described above, such map information or
traffic information are received through the signal receiving unit 211 of the
broadcasting module 103. Thereafter, the broadcasting module 103 may extract
the
text data from the received mobile broadcast service data, which are then
outputted to
the display unit 110 or the TTS module 112. As mentioned above, the mobile
broadcast service data according to the present invention includes text data.
Therefore,
the method of processing the mobile broadcast service data according to the
present
invention may be applied to the method of processing the text data.
[1311 The synchronization unit 213 receives the IF signal outputted from the
signal
receiving unit 211, so as to perform carrier recovery and timing recovery,
thereby
being changed (or converted) to a baseband signal. Thus, channel equalization
is
performed. The output of the synchronization unit 213 is inputted to the
mobile
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broadcast data processing unit 215. The mobile broadcast service data
processing unit
215 performs error correction decoding on the mobile broadcast service data
among
the output data of the synchronization unit 213. Thereafter, the mobile
broadcast
service data, which are error correction decoded by the mobile broadcast
service data
processing unit 215, are inputted to the demultiplexer 216. The
synchronization unit
213 and the mobile broadcast service data processing unit 215 will be
described in
more detail with reference to FIG. 4.
[132] The demultiplexer 216 may separate the AN stream from the data. More
specifically, when the mobile broadcast service data outputted from the data
de-
randomizer 533 of the mobile broadcast service data processing unit 215
correspond to
PES-type data, the demultiplexer 216 outputs the corresponding data to the AN
decoder 217. On the other hand, when the outputted mobile broadcast service
data
correspond to section-type data, the demultiplexer 216 outputs the
corresponding data
to the data decoder 218. Furthermore, regardless of the mobile broadcast
service data,
when the AN stream is outputted from the data derandomizer 533 of the mobile
broadcast service data processing unit 215, the AN stream is outputted to the
AN
decoder 217. Alternatively, when data are outputted from the data derandomizer
533,
the data may be outputted to the data decoder 218. According to the present
invention,
text data are inputted to the data decoder 218, thereby being extracted.
[133] Herein, the section-type mobile broadcast service data packet outputted
to the
data decoder 218 may correspond either to mobile broadcast service data or a
PSI/PSIP
table.
[134] According to the embodiment of the present invention, the mobile
broadcast
service data carried by the payload within the section-type mobile broadcast
service
data packet corresponds to a DSM-CC section.
[135] At this point, based upon the control of the data decoder 218, the
demultiplexer
216 performs section filtering, thereby discarding duplicate sections and
outputting
only the non-duplicate sections to the data decoder 218.
[136] Also, by performing section filtering, the demultiplexer 216 may output
only a
wanted (or desired) section (e.g., a section configuring a VCT) to the data
decoder 218.
[137] The VCT includes information indicating the type of the mobile broadcast
service data that are being received. The section filtering method may include
a
method of verifying the PID of a table defined by the MGT, such as the VCT,
prior to
performing the section filtering process. Alternatively, the section filtering
method
may also include a method of directly performing the section filtering process
without
verifying the MGT, when the VCT includes a fixed PID (i.e., a base PID). At
this
point, the demultiplexer 216 performs the section filtering process by
referring to a
table-id field, a version_number field, a section-number field, etc.
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[1381 The data decoder 218 parses sections of the demultiplexed PSUPSIP
tables. Then,
the data decoder 218 stores the parsed result in the PSI/PSIP information
storage unit
219 as database.
[1391 For example, the data decoder 218 groups sections having the same table
identifier (table-id) so as to form a table. Then, the data decoder 218 parses
the table
and the parsed result in the PSI/PSIP information storage unit 219 as
database. In
performing the parsing process, the data decoder 218 reads all remaining
section data,
which have not been processed with section filtering, and actual section data.
Thereafter, the data decoder 218 stores the read data to the PSI/PSIP
information
storage unit 219.
[1401 Herein, the table-id field, the section_number field, and the
last_section_number
field included in the table may be used to indicate whether the corresponding
table is
configured of a single section or a plurality of sections. For example, TS
packets
having the PID of the VCT are grouped to form a section, and sections having
table
identifiers allocated to the VCT are grouped to form the VCT.
[1411 Additionally, the data decoder 218 either stores the demultiplexed
mobile
broadcast service data to the data storage unit 221 as database, or outputs
the de-
multiplexed mobile broadcast service data to the display unit 110 and/or
speaker
through the application controller 220 and control unit 100.
[1421 By parsing system information tables, such as PMT and VCT, information
on the
virtual channel through which the mobile broadcast service data are
transmitted may be
obtained. Also, information as to whether PES-type mobile broadcast service
data are
being transmitted through the corresponding virtual channel or information as
to
whether section-type mobile broadcast service data are being transmitted
through the
corresponding virtual channel may also be obtained. By parsing the system
information
tables, the type of the mobile broadcast service data being transmitted may
also be
known.
[1431 More specifically, the data decoder 218 may extract information on
virtual
channels by referring to element stream types (ES types) within system
information
tables (i.e., VCT and/or PAT/PMT) and PIDs. Also, when the extracted channel
in-
formation indicate that PES-type mobile broadcast service data exist in a
virtual
channel, AN PID of the corresponding virtual channel (VCH) within a channel
map is
set up, thereby controlling an AN demultiplexing process of the demultiplexer
216.
[1441 Meanwhile, when the extracted channel information indicate that section-
type
mobile broadcast service data exist in a virtual channel, the demultiplexer
216 de-
multiplexes the mobile broadcast service data transmitted through the virtual
channel,
thereby either storing the demultiplexed data in the data storage unit 221 or
outputting
the demultiplexed data to an output device, such as the display unit 110 and
thevoice
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output unit 109.
[145] For example, when it is assumed that the mobile broadcast service data
are
transmitted in DSM-CC sections, the presence (or existence) of the mobile
broadcast
service data may be known by parsing a stream_type field value within the PMT
or the
stream-type field value of the service location descriptor included in the
VCT. More
specifically, when the stream-type field value is equal to `0x95', this
indicates that the
mobile broadcast service data are transmitted to the corresponding virtual
channel.
[146] By performing section filtering, the demultiplexer 216 may output only
an ap-
plication information table (AIT) to the data decoder 218.
[147] The AIT includes information of an application that is operated in the
telematics
terminal for the data service. The AIT may include application information,
such as ap-
plication name, application version, application priority, application ID,
application
status (i.e., auto-start, user-specific settings, kill, etc.), application
type (i.e., Java or
HTML), position (or location) of stream including application class and data
files, ap-
plication platform directory, and location of application icon. Therefore, by
using such
information, the application may store information required for its operation
in the
flash memory 222.
[148] The application that is operated by the application controller 220 may
be received
along with the broadcast data and, then, updated. A data broadcasting
application
manager, which is executed by the application controller 220 in order to
operate the
corresponding application, may be provided with a platform, which can execute
an ap-
plication program. Herein, for example, the platform may correspond to a Java
virtual
machine for executing a Java program. Furthermore, the data decoder 218
controls the
demultiplexing of the system information table, which corresponds to the
information
table associated with the channel and events. Thereafter, an AN PID list may
be
transmitted to the channel manager.
[149] The information table associated with the channel and events extracted
from the
data decoder 218 may indicate information on the channel including the text
data.
Therefore, the present invention may embodied so that, when the telematics
terminal is
informed by the system information that the text data are received, the
telematics
terminal may directly output the received text data in the form of a text
message on the
display screen. Alternatively, the telematics terminal may synthesize the text
data to
voice signals, which are then outputted to the voice output unit 109.
Furthermore,
while the text data is being outputted to the screen in the form of a text
message, the
telematics terminal may simultaneously synthesize the text data to voice
signals, which
are then outputted to the voice output unit 109 as well. This function may
either be set
as a default function of the telematics terminal or be specified by the user.
In order to
do so, a notification message for setting up the TTS function may be outputted
to the
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display unit 110. Furthermore, the user may input environment settings for the
telematics terminal in advance, so that the TTS function can be automatically
activated.
[1501 The channel manager may refer to the channel map in order to transmit a
request
for receiving system-related information data to the data decoder 218, thereby
receiving the corresponding result. In addition, the channel manager may also
control
the channel tuning of the tuner corresponding to the signal receiving unit
211. The
channel manager controls the signal receiving unit 211 and the data decoder
218, so as
to manage the channel map so that it can respond to the channel request made
by the
user. More specifically, channel manager sends a request to the data decoder
218 so
that the tables are parsed. Herein, the tables are associated with the
channels that are to
be tuned. The results of the parsed tables are reported to the channel manager
by the
data decoder 218. Thereafter, based on the parsed results, the channel manager
updates
the channel map and sets up a PID in the demultiplexer 216 for demultiplexing
the
tables associated with the mobile broadcast service data from the mobile
broadcast
service data packet. Furthermore, the channel manager may directly control the
de-
multiplexer 216, so as to directly set up the AN PID, thereby controlling the
AN
decoder 217. The AN decoder 217 may decode each of the audio data and the
video
data from the demultiplexed mobile broadcast service data and, then, output
the
decoded data.
[1511 FIG. 4 illustrates a detailed block diagram of the synchronization unit
213 and
the mobile broadcast service data processing unit 215.
[1521 Referring to FIG. 4, the synchronization unit 213 includes a modulator
511, a
channel equalizer 512, and a known sequence detector 513.
[1531 And, the mobile broadcast service data processing unit 215 includes a
block
decoder 531, a RS frame decoder 532, and a data derandomizer 533.
[1541 More specifically, the demodulator 511 of the synchronization unit 213
performs
self-gain control, carrier recovery, and timing recovery processes on the
inputted IF
signal, thereby modifying the IF signal to a baseband signal. Then, the
demodulator
511 outputs the modified IF signal to the channel equalizer 512 and the known
sequence detector 513. The channel equalizer 512 compensates the distortion of
the
channel included in the demodulated signal and then outputs the error-
compensated
signal to the block decoder 531 of the mobile broadcast service data
processing unit
215.
[1551 At this point, the known sequence detector 513 detects the known
sequence place
inserted by the transmitting end from the input/output data of the demodulator
511
(i.e., the data prior to the demodulation process or the data after the
demodulation
process). Thereafter, the place information (or position indicator) along with
the
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symbol sequence of the known data, which are generated from the detected
place, is
outputted to the demodulator 511 and the channel equalizer 512. Also, the
known
sequence detector 513 outputs a set of information to the block decoder 531.
This set
of information is used to allow the block decoder 531 of the receiving system
to
identify the mobile broadcast service data that are processed with additional
encoding
from the transmitting system and the main broadcast service data that are not
processed
with additional encoding.
[156] The demodulator 511 uses the known data (or sequence) position indicator
and
the known data symbol sequence during the timing and/or carrier recovery,
thereby
enhancing the demodulating performance. Similarly, the channel equalizer 512
uses
the known sequence position indicator and the known data symbol sequence so as
to
enhance the equalizing performance. Moreover, the decoding result of the block
decoder 531 may be fed-back to the channel equalizer 512, thereby enhancing
the
equalizing performance.
[157] The channel equalizer 512 may perform channel equalization by using a
plurality
of methods. An example of estimating a channel impulse response (CIR), so as
to
perform channel equalization, will be given in the description of the present
invention.
Most particularly, an example of estimating the CIR in accordance with each
region
within the data group, which is hierarchically divided and transmitted from
the
transmitting system, and applying each CIR differently will also be described
herein.
Furthermore, by using the known data, the place and contents of which is known
in
accordance with an agreement between the transmitting system and the receiving
system, and the field synchronization data, so as to estimate the CIR, the
present
invention may be able to perform channel equalization with more stability.
[158] Herein, the data group that is inputted for the equalization process is
divided into
regions A to D, as shown in FIG. 5. More specifically, in the example of the
present
invention, each region A, B, C, and D are further divided into MPH blocks B4
to B7,
MPH blocks B3 and B8, MPH blocks B2 and B9, MPH blocks B1 and B10, re-
spectively.
[159] More specifically, a data group can be assigned and transmitted a
maximum the
number of 4 in a VSB frame in the transmitting system. In this case, all data
group do
not include field synchronization data. In the present invention, the data
group
including the field synchronization data performs channel-equalization using
the field
synchronization data and known data. And the data group not including the
field syn-
chronization data performs channel-equalization using the known data. For
example,
the data of the MPH block B3 including the field synchronization data performs
channel-equalization using the CIR calculated from the field synchronization
data area
and the CIR calculated from the first known data area. Also, the data of the
MPH
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blocks B 1 and B2 performs channel-equalization using the CIR calculated from
the
field synchronization data area and the CIR calculated from the first known
data area.
Meanwhile, the data of the MPH blocks B4 to B6 not including the field syn-
chronization data performs channel-equalization using CIRS calculated from the
first
known data area and the third known data area.
[1601 As described above, the present invention uses the CIR estimated from
the field
synchronization data and the known data sequences in order to perform channel
equalization on data within the data group. At this point, each of the
estimated CIRs
may be directly used in accordance with the characteristics of each region
within the
data group. Alternatively, a plurality of the estimated CIRs may also be
either in-
terpolated or extrapolated so as to create a new CIR, which is then used for
the channel
equalization process.
[1611 Herein, when a value F(Q) of a function F(x) at a particular point Q and
a value
F(S) of the function F(x) at another particular point S are known,
interpolation refers to
estimating a function value of a point within the section between points Q and
S.
Linear interpolation corresponds to the simplest form among a wide range of in-
terpolation operations. The linear interpolation described herein is merely
exemplary
among a wide range of possible interpolation methods. And, therefore, the
present
invention is not limited only to the examples set forth herein.
[1621 Alternatively, when a value F(Q) of a function F(x) at a particular
point Q and a
value F(S) of the function F(x) at another particular point S are known,
extrapolation
refers to estimating a function value of a point outside of the section
between points Q
and S. Linear extrapolation is the simplest form among a wide range of
extrapolation
operations. Similarly, the linear extrapolation described herein is merely
exemplary
among a wide range of possible extrapolation methods. And, therefore, the
present
invention is not limited only to the examples set forth herein.
[1631 Meanwhile, if the data being inputted to the block decoder 531, after
being
channel-equalized by the equalizer 512, correspond to the data having both
block
encoding and trellis encoding performed thereon (i.e., the data within the RS
frame, the
signaling information data, etc.) by the transmitting system, trellis decoding
and block
decoding processes are performed on the inputted data as inverse processes of
the
transmitting system. Alternatively, if the data being inputted to the block
decoder 531
correspond to the data having only trellis encoding performed thereon (i.e.,
the main
broadcast service data), and not the block encoding, only the trellis decoding
process is
performed on the inputted data as the inverse process of the transmitting
system.
[1641 At this point, the data group decoded by the block decoder 531 is
inputted to the
RS frame decoder 532, whereas the main broadcast service data are not
outputted to
the RS frame decoder 532. If a main broadcast service data processing unit for
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processing the main broadcast service data is provided, then, instead of being
discarded, the main broadcast service data may be sent to the main broadcast
service
data processing unit. In this case, the main broadcast service data processing
unit may
include a data deinterleaver, a RS decoder, and a derandomizer. However, the
main
broadcast service data processing unit may not be required in a system
structure that
only receives the mobile broadcast service data and may, therefore, be
omitted.
[165] The trellis decoded and block decoded data by the block decoder 531 are
then
outputted to the RS frame decoder 532. More specifically, the block decoder
531
removes the known data, data used for trellis initialization, and signaling
information
data, MPEG header, which have been inserted in the data group, and the RS
parity
data, which have been added by the RS encoder/non-systematic RS encoder or non-
systematic RS encoder of the transmitting system. Then, the block decoder 531
outputs
the processed data to the RS frame decoder 532. Herein, the removal of the
data may
be performed before the block decoding process, or may be performed during or
after
the block decoding process.
[166] If the inputted data correspond to the data having only trellis encoding
performed
thereon and not block encoding, the block decoder 531 performs Viterbi (or
trellis)
decoding on the inputted data so as to output a hard decision value or to
perform a
hard-decision on a soft decision value, thereby outputting the result.
[167] Meanwhile, if the inputted data correspond to the data having both block
encoding process and trellis encoding process performed thereon, the block
decoder
531 outputs a soft decision value with respect to the inputted data.
[168] In other words, if the inputted data correspond to data being processed
with block
encoding by the block processor and being processed with trellis encoding by
the
trellis encoding module, in the transmitting system, the block decoder 531
performs a
decoding process and a trellis decoding process on the inputted data as
inverse
processes of the transmitting system. At this point, the RS frame encoder of
the pre-
processor included in the transmitting system may be viewed as an outer (or
external)
encoder. And, the trellis encoder may be viewed as an inner (or internal)
encoder.
When decoding such concatenated codes, in order to allow the block decoder 531
to
maximize its performance of decoding externally encoded data, the decoder of
the
internal code should output a soft decision value.
[169] Meanwhile, the RS frame decoder 532 receives only the error correction
encoded
mobile broadcast service data (i.e., the RS-encoded and CRC-encoded mobile
broadcast service data) that are transmitted from the block decoder 531.
[170] The RS frame decoder 532 performs an inverse process of the RS frame
encoder
included in the transmitting system so as to correct the errors within the RS
frame.
Then, the RS frame decoder 532 adds the 1-byte MPEG synchronization data,
which
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had been removed during the RS frame encoding process, to the error-corrected
mobile
broadcast service data packet. Thereafter, the processed data packet is
outputted to the
data derandomizer 533.
[171] The data derandomizer 533 performs a derandomizing process, which
corresponds to the inverse process of the randomizer included in the
transmitting
system, on the received mobile broadcast service data. Thereafter, the
derandomized
data are outputted, thereby obtaining the mobile broadcast service data
transmitted
from the transmitting system.
[172] FIG. 7 illustrates a block diagram of a TTS module according to an
embodiment
of the present invention. Referring to FIG. 3 and FIG. 7, the functions of the
TTS
module 112 and the control unit 100 will now be described in detail. The TTS
module
112 includes a language processor 71, a voice database (DB) 72, and a voice
processor
73. The elements of the TTS module 112 are mostly based on their functions.
And,
each element may be embodied on a single chip.
[173] When text data are inputted, the language processor 71, the language
processor
71 analyzes the received text data, thereby detecting letters (or characters),
numbers,
symbols, and signs, and deciding what the text data signify and how to
pronounce the
analyzed text. For example, if the inputted text data is "Exchange rate for 1
USD at
10:00, June 8, 2007", then depending upon the significance of each symbol,
sign, and
number, the inputted text may be converted into the following sentence,
"Exchange
rate for one US dollar at ten o'clock, June eighth two thousand and seven."
Then, the
voice DB 71 stores the text matching the voice data. With respect to the
received text
data, the voice processor 73 searches for the voice signal corresponding to
the decided
pronunciation from the voice database 72, thereby matching and synthesizing
the data.
The voice processor 73 then outputs the synthesized voice signal to the voice
output
unit 109. The detailed operations of the language processor 71, the voice
database
(DB) 72, and the voice processor 73 will be described in more detail with
reference to
FIG. 9.
[174] The control unit 100 may either automatically set up the execution of
the TTS
module 112 function, or manually set up the execution in accordance with the
user's
select signal. For example, when the power of the telematics terminal is
turned on, the
function of the TTS module 112 may be set to a default mode. Also, when the
vehicle
exceeds a predetermined speed, the function of the TTS module 112 may be
executed.
More specifically, when the vehicle is not moving or when the vehicle is
moving at a
very low speed, the TTS function of the TTS module 112 is not activated.
However,
when the vehicle reaches a predetermined speed (e.g., at least 30 km/h), the
control
unit 100 may control the TTS module 112 so that the TTS function is executed.
Default settings may be inputted for the predetermined speed, or manual
settings may
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be inputted by the user.
[175] Alternatively, when the user inputs a select signal for executing the
function of
the TTS module 112, the control unit 100 may execute the functions of the TTS
module based upon the user's select signal. FIG. 10(a) illustrates an
exemplary on-
screen display for setting up the function of the TTS module 112. Referring to
FIG.
10(a), the screen may include an additional information display 10, a playback
screen
display 20, a text display 30, and a TTS function setup 40. For example, the
user may
select the TTS function setup 40. Herein, the user may input a select signal
using a
touch screen or by inputting a select key.
[176] The control unit 100 may control filtering in order to receive text data
or to
perform voice signal synthesis on the received text data. At this point, the
control unit
100 controls the broadcast receiver 211, so that only the mobile broadcast
service data
including the desired text data can be received. Alternatively, the control
unit 100 may
also control the broadcast receiver 211, so that all text data can be
extracted from the
mobile broadcast service data, thereby outputting only the desired text data.
At this
point, all text data are outputted from the display unit 110 in the form of
text messages.
And, only the desired text data are synthesized as voice signals by the TTS
module
112. The control unit 100 may control the broadcast receiver 211 so that only
the
desired text data can be received, or the control unit 100 may control the TTS
module
112 so that only the desired text data are synthesized to voice signals.
However, this is
merely exemplary. The control unit 100 may control the TTS module 112 so that
only
the text data desired by the user are synthesized to voice signals (or
filtered out) and
then outputted.
[177] In order to perform the above-described filtering process, the control
unit 100
may extract service data such as PSI/PSIP information from the received mobile
broadcast service data so as to perform the filtering process. Herein, the
PSI/PSIP in-
formation indicates the type of the text data. For example, when the user
wishes to
output only the text data including traffic condition information as the voice
signal, the
control unit 100 extracts the PSUPSIP information of the received mobile
broadcast
service data, so that only the text data categorized as traffic condition text
data can be
received.
[178] FIG. 10(b) illustrates an exemplary on-screen display for selectively
outputting
voice signals. Referring to FIG. 10(b), the screen may include an additional
in-
formation display 10, a playback screen display 20, a text display 30, a TTS
function
setup 40, and an information select 50. Herein, the user may select an on/off
mode
from the TTS function setup unit 40, thereby selecting whether or not to
execute the
TTS module 112. Also, the user may select the desired text data from the
information
select 50. The control unit 100 may control the output of the synthesized
voice signal
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from the TTS module 112. More specifically, the control unit 100 may control
the on/
off mode for the output of the synthesized voice signal from the TTS module
112. For
example, when an external event occurs (herein, any event colliding with the
voice
signal output of the TTS module 112 will be referred to as an "external
event"), the
control unit 100 may control the output of the voice signals. At this point,
the control
unit 100 may control the output on/off mode of the TTS module 112, thereby
controlling the output of the voice signals. The control unit 100 may also
control the
output on/off mode of the voice output unit 109, thereby controlling the
output of the
voice signals.
[179] Examples of the external event may include receiving an incoming phone
call
through the telecommunication module provided in the telematics terminal,
performing
audible road guidance by the navigation unit 108 also provided in the
telematics
terminal. When such external event occurs, the control unit 100 may turn the
output
mode of the TTS module 112 off or may reduce the output of voice signals. Al-
ternatively, based upon the priority level of the external event, the voice
signal that is
to be outputted may be selected, and the control unit 100 may control the TTS
module
112 so that the selected voice signal can be outputted. Finally, when the
external event
is completed, the control unit 100 may control the telematics terminal so that
the TTS
module 112 can return to its initial status and be executed.
[180] FIG. 8 illustrates a flow chart showing process steps of a method for
processing
data according to a first embodiment of the present invention. Referring to
FIG. 8, the
method for processing data includes the steps of receiving mobile broadcast
data
including text data (S801), extracting text data included in the received
mobile
broadcast service data (S802), converting the extracted text data to voice
signals
(S803), and outputting the text data converted to voice signals (S804).
[181] In the step of receiving mobile broadcast data including text data
(S801), the
telematics terminal may receive system information for receiving the mobile
service
broadcast data including the text data. More specifically, the telematics
terminal may
receive information on the channel transmitting the mobile broadcast service
data
including text data as the system information, and the telematics terminal may
also
receive event information on the specific time when the mobile broadcast
service data
including text data are received. Therefore, the received system information
may be
used to output a schedule list for the text data. For example, when receiving
the mobile
broadcast service data, an event information (including information on
receiving
channel and time) indicating that text data will be received along with the
mobile
broadcast service data may be outputted in a program guide information.
[182] At this point, if the user wishes voice signals of the corresponding
text data to be
outputted, then text data are extracted from the mobile broadcast service data
received
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at the corresponding time and from the corresponding channel. Thereafter, the
extracted text data may be converted to voice signals, thereby being
outputted.
Furthermore, when the event information is received, the corresponding channel
is au-
tomatically tuned at the corresponding time. Then, the text data are
extracted, which
are then converted to voice signals so as to be outputted. The description of
the step of
extracting text data included in the received mobile broadcast service data
(5802) is
focused mostly on the synchronization unit 213, mobile broadcast service data
processing unit 215, and AN decoder 217 shown in FIG. 3. The step of
converting the
extracted text data to voice signals (S803) will be described in more detail
with
reference to FIG. 9. Finally, in the step of outputting the text data
converted to voice
signals (S804), the voice signal synthesized by the TTS module 112 is
outputted.
[1831 FIG. 9 illustrates an exemplary method of synthesizing voice signals in
the TTS
module of FIG. 7. The process methods of the language processor 71, the voice
DB 72,
and the voice processor 73 will be described with reference to FIG. 9. When
text data
are inputted, the language processor 71 analyzes non-linguistic characters,
such as
signs, symbols, and numbers, and performs a process of converting the non-
linguistic
characters to linguistic characters. Accordingly, the morphemes and phrases of
the
converted linguistic characters are analyzed and processed to variable
phoneme. The
voice DB 72 corresponds to a medium for storing voice data matching with the
analyzed linguistic characters.
[1841 Hereinafter, the process of generating voice data will now be described.
More
specifically, a recording script is configured, thereby recording the voice.
Then, the
voice is labeled and clustered, thereby configuring the voice DB. Either the
user
directly inputs voice data to the voice DB, or the voice DB is configured
during the
fabrication process of the telematics terminal. The voice processor 73
generates
temperament (i.e., tone, length, size, pause, etc.) with respect to the text
data analyzed
by the language processor 71. Subsequently, an optimum phonetic shift sequence
is
created. Thereafter, the voice processor 73 reads (or opens) the corresponding
voice
data from the voice DB 72 so as to synthesize a voice signal, thereby
outputting the
synthesized voice signal.
[1851 FIG. 11 illustrates a block diagram showing a structure of a telematics
terminal
provided with a broadcasting module and a TTS module according to a second
embodiment of the present invention, wherein text information is received from
the
VSB mode mobile broadcast service data, and wherein the received text
information is
synthesized, thereby being outputted as a voice signal.
[1861 Referring to FIG. 11, the broadcasting module further includes a storage
unit 223
and a memory 224, which are used to perform instant recording, reserved (or
pre-
programmed) recording, and time shift on the mobile broadcast service data.
Apart
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from the storage unit 223 and the memory 224, the structures and operations of
the
remaining elements of the telematics terminal are identical to the
corresponding
elements of the telematics terminal shown in FIG. 3. Therefore, the
description of FIG.
11 will mainly be focused on the storage unit 223 and the memory 224.
Furthermore,
the structures and operations of the synchronization unit 213 and the mobile
broadcast
service data processing unit 215 are identical to those described in FIG. 4.
Therefore,
in FIG. 11, a detailed description of the same will be omitted for simplicity.
[187] Either a hard disk drive (HDD) or a detachable external memory unit may
be
used as the storage unit 223. More specifically, the mobile broadcast service
data de-
multiplexed by the demultiplexer 216 may be outputted to the AN decoder 217 or
the
data decoder 218. Alternatively, based upon the control of the memory
controller 224,
the demultiplexed mobile broadcast service data may also be written (or
recorded) in
the storage unit 223. When the user selects one of instant recording, reserved
(or pre-
programmed) recording, and time shift, the memory controller 224 records the
cor-
responding mobile broadcast service data demultiplexed by the demultiplexer
216 in
the storage unit 223. Additionally, when the user selects the playback of the
mobile
broadcast service data stored in the storage unit 223, the mobile broadcast
service data
stored in the storage unit 223 is read and outputted based upon the control of
the
memory controller 224. Subsequently, after being decoded by the AN decoder 217
or
the data decoder 218, the decoded mobile broadcast service data may be
provided to
the user.
[188] The storage controller 224 may control the fast-forward, rewind, slow
motion,
and instant replay functions of the data that are stored in the storage unit
223. Herein,
the instant replay function corresponds to repeatedly viewing scenes that the
viewer (or
user) wishes to view once again. The instant replay function may be performed
on
stored data and also on data that are currently being received in real time by
as-
sociating the instant replay function with the time shift function. In order
to prevent
illegal duplication (or copies) of the input data being stored in the storage
unit 223, the
storage controller 224 scrambles the input data and stores the scrambled data
in the
storage unit 223. Also, based upon the playback command of the user, the
memory
controller 224 reads and outputs the data scrambled and stored in the storage
unit 223,
so as to descramble the read data, thereby outputting the descrambled data to
the de-
multiplexer 216. According to another embodiment of the present invention, the
above-described functions of the memory controller 224 and the storage unit
223, such
as the instant recording, pre-programmed recording, time shift, playback, and
instant
replay, may be performed by the write/read media driver 104 instead of the
storage
unit 223.
[189] FIG. 12 illustrates a block diagram showing a structure of a telematics
terminal
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provided with a broadcasting module and a TTS module according to a third
embodiment of the present invention, wherein text information is received from
the
VSB mode mobile broadcast service data, and wherein the received text
information is
synthesized, thereby being outputted as a voice signal. Referring to FIG. 12,
the
broadcasting module further includes a descrambler 225 between the
demultiplexer
216 and the AN decoder 217, which is used to descramble the mobile broadcast
service data that are scrambled and outputted from the transmitting system.
Apart from
the descrambler 225, the structures and operations of the remaining elements
of the
telematics terminal are identical to the corresponding elements of the
telematics
terminal shown in FIG. 3. Therefore, the description of FIG. 12 will mainly be
focused
on the descrambler 225. Furthermore, the structures and operations of the syn-
chronization unit 213 and the mobile broadcast service data processing unit
215 are
identical to those described in FIG. 4. Therefore, in FIG. 12, a detailed
description of
the same will be omitted for simplicity.
[190] Referring to FIG. 12, the descrambler 225 is provided between the
demultiplexer
216 and the AN decoder 217. However, according to another embodiment of the
present invention, the descrambler 225 may also be provided between the de-
multiplexer 216 and the data decoder 218. Also, an authenticator (not shown)
may
further be provided in each descrambler. Alternatively, a separate
authenticator (not
shown) may be provided so as to control the scrambling of the two
descramblers. The
authentication process may also be performed by the control unit 100. When the
mobile broadcast service data demultiplexed by the demultiplexer 216 are
scrambled,
the descrambler 225 descrambles the corresponding data and outputs the
descrambled
data to the AN decoder 217. At this point, the descrambler 225 receives the au-
thentication result and/or data required for the descrambling process, which
are then
used to descramble the corresponding data.
[191] More specifically, in order to provide service to prevent the
transmitted mobile
broadcast service data from being illegally duplicated (or copied) or viewed,
or in
order to provide charged broadcast services, the broadcasting station may
scramble the
mobile broadcast service data and transmit the scrambled data. Accordingly,
since the
descrambler 225 is required to descramble the scrambled mobile broadcast
service
data, an authentication process may be performed by an authentication means
prior to
the descrambling process. Herein, the descrambler 225 may also be provided as
a
detachable unit of the telematics terminals in the form of a slot or a memory
stick.
[192] In order to perform the descrambling process, the descrambler 225 may
perform
the authentication process. Herein, the authentication process determines
whether the
telematics terminal is a legitimate host entitled to receive the charged
mobile broadcast
service data (i.e., charged broadcast programs (or contents)). For example,
the au-
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thentication process may be carried out by comparing an internet protocol (IP)
address
of an IP datagram, which is included in the broadcast program (or contents)
being
received, to a unique address of the corresponding telematics terminal.
Herein, the
unique address of the telematics terminal may correspond to a media access
control
(MAC) address.
[1931 According to another embodiment of the authentication process,
identification
(ID) information pre-standardized by the transmitting system and receiving
system
may be defined. Then, the transmitting system may transmit ID information of
the
telematics terminal that has requested the charged broadcast service.
Accordingly, the
telematics terminal may determine the authenticity between its own
identification
number and the ID information received from the transmitting system, thereby
performing the authentication process. The transmitting system generates a
database so
as to store the unique ID information of the telematics terminal that has
requested the
charged broadcast service. Thereafter, when scrambling the charged mobile
broadcast
service data, the transmitting system include an entitlement management
message
(EMM) in the ID information and transmits the processed ID information. Al-
ternatively, when the corresponding mobile broadcast service data are
scrambled, a
message (e.g., entitlement control message (ECM) or EMM), such as a
conditional
access system (CAS) information, mode information, message position
information,
and so on, which are applied in the scrambling process, may be transmitted via
a cor-
responding data header or another packet.
[1941 More specifically, the ECM may include a control word (CW) that is used
in the
scrambling process. At this point, the control word may be encoded (or
encrypted)
with an authentication key. The EMM may include an authentication key and en-
titlement information of the corresponding data header. The authentication
information
may be encoded with a unique distribution key of the telematics terminal. When
the
mobile broadcast service data are scrambled by using the control word (CW),
and
when the information required for authentication and the information for
descrambling
are transmitted from the transmitting system, the transmitting system may
encode the
control word (CW) with an authentication key, which is then included in an
entitlement
control message (ECM) and transmitted.
[1951 Furthermore, the transmitting system includes the authentication key
used for
encoding the control word (CW) and a reception entitlement of the telematics
terminal
(e.g., a standardized serial number of a telematics terminal that is entitled
to receive
data) in an entitlement management message (EMM), which is then transmitted.
Therefore, the telematics terminal may extract its unique ID information and
may
extract the ID information included in the EMM of the mobile broadcast service
data
being received, so as to determine the authenticity between the extracted ID
in-
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formation, thereby carrying out the authentication process. If the
authentication result
shows that the ID information are identical, the corresponding telematics
terminals
may be determined as a legitimate receiver entitled to receive data.
[196] According to yet another embodiment of the authentication process, the
telematics terminal may be provided with an authenticator on a detachable
external (or
outer) module. At this point, the telematics terminal and the outer module are
interfaced via a common interface (CI). More specifically, the outer module
may
receiver scrambled data from the telematics terminal via the common interface
(CI),
thereby descrambling the received data. Alternatively, the telematics terminal
may also
selectively transmit only the information required for the descrambling
process to the
corresponding telematics terminal. Furthermore, the common interface (CI) may
be
configured of one physical layer and at least one protocol layer. Herein, in
con-
sideration of a future expansion, the protocol layer may include at least one
layer each
providing an independent function.
[197] The outer module may correspond to a memory or card having no
descrambling
function yet having key information and authentication information, which were
used
in the scrambling process, stored therein. Alternatively, the outer module may
also
correspond to a card including a descrambling function. More specifically, the
module
may include the descrambling function in the form of middleware or software.
At this
point, the telematics terminal and the outer module should both be
authenticated in
order to be able to provide the user with the charged mobile broadcast service
data,
which are supplied by the transmitting system. Therefore, the transmitting
system may
provide the charged mobile broadcast service data only to the authenticated
telematics
terminal and module pair. Thus, the telematics terminal and outer module may
be
mutually authenticated (or processed with two-way authentication) via the
common
interface (CI). The outer module may also communicate with the control unit
100 of
the telematics terminal, thereby authenticating the corresponding telematics
terminal.
[198] The telematics terminal may authenticate the outer module via the common
interface. And, the module may extract the unique ID of the telematics
terminal and its
own unique ID during the mutual authentication (or two-way authentication)
process,
which are then transmitted to the transmitting system. Thereafter, the
transmitting
system uses the received ID information (or value) as information for
determining
whether to start the requested service or as charged fee information. When
required,
the control unit 100 may transmit the charged fee information to a
transmitting system
located in a remote site via the telecommunication module 102. Furthermore,
the
telematics terminal may also receive authentication-associated data from a
mobile
telecommunications service provider to which the user is subscribed, instead
of
receiving the authentication-associated data from the transmitting system that
provides
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the mobile broadcast service data. In this case, the authentication-associated
data may
be scrambled by the transmitting system that provides the mobile broadcast
service
data and transmitted by passing through the domestic carrier. Otherwise, the
au-
thentication-associated data may be scrambled by the domestic carrier and then
transmitted.
[199] According to yet another embodiment of the authentication process, the
au-
thentication process may be performed using software without having to depend
on
hardware. More specifically, when a memory card having software pre-stored
therein
by downloading CAS software is inserted, the telematics terminal receives the
CAS
software from the inserted memory card. Thereafter, the CAS software is loaded
so as
to perform the authentication process. Herein, a flash memory or a compact
hard disk
may be used as the memory card. The memory card may be used in at least one
telematics terminal depending upon the contents, authentication, scrambling,
fee-
charging of the CAS software stored therein. However, the CAS software
includes at
least information required for the authentication process and information
required for
the descrambling process.
[200] The CAS software read from the memory card is stored in a storage unit
(e.g.,
flash memory 222) within the telematics terminal. Then, the stored CAS
software may
be operated on the middleware in the form of an application. In this example,
a Java
middleware will be given as the middleware. Herein, the outer interface unit
105 may
include a common interface (CI) in order to be connected with the flash memory
222.
In this case, an authentication process between the transmitting system and
telematics
terminal or between the telematics terminal and memory card is performed. The
memory card entitled to receive data may include information on an ordinary
(or
normal) authenticatable telematics terminal. For example, information on the
telematics terminal includes unique information, such as a standardized serial
number,
on the corresponding telematics terminal. Therefore, the authentication
process
between the memory card and telematics terminal may be performed by comparing
the
unique information, such as the standardized serial number, included in the
memory
card with the unique information of the corresponding telematics terminal.
[201] Herein, the authentication process between the telematics terminal and
memory
card may be performed while the CAS software performs a Java middleware-based
execution (or operation). For example, the telematics terminal determines
whether the
unique serial number of the telematics terminal, which is included in the CAS
software, identically matches the unique serial number of the telematics
terminal,
which has been read by the control unit 100 of the telematics terminal. Then,
when the
comparison result shows that the two unique serial numbers, the corresponding
memory card is determined to be a normal memory card, which can be used by the
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telematics terminal. At this point, the CAS software may also be equipped in
the flash
memory 222 prior to the shipping of the telematics terminal. Alternatively,
the CAS
software may be stored in the flash memory 222 from the transmitting system,
the
module or memory card. The descrambling function may be operated in the form
of an
application by the data broadcasting application.
[2021 The CAS software parses the EMM/ECM packet outputted from the de-
multiplexer 216 in order to verify whether the corresponding telematics
terminal is
entitled to receive data. Thus, the CAS software may obtain information
required for
the descrambling process (i.e., a CW) and provide the information to the
descrambler
225. The CAS software performing Java middleware-based operation reads the
unique
number of the corresponding telematics terminal. Then, the CAS software
compares
the read unique number with the unique number of the telematics terminal that
is
transmitted to the EMM, thereby verifying whether the corresponding telematics
terminal is entitled to receive data. Once the entitlement of the telematics
terminal is
verified, the corresponding mobile broadcast service information transmitted
to the
ECM and the entitlement of the corresponding mobile broadcast service are used
to
verify whether the telematics terminal is entitled to receive the
corresponding mobile
broadcast service.
[2031 Once the entitlement of receiving the corresponding (or requested)
mobile
broadcast service is verified, the authentication key transmitted to the EMM
is used to
decipher the encoded (or encrypted) control word (CW), which is transmitted to
the
ECM. Thereafter, the deciphered control word is outputted to the descrambler
225. The
descrambler 225 then uses the control word to descramble the mobile broadcast
service. Meanwhile, the CAS software that is stored in the memory card may be
expanded depending upon a charged mobile broadcast service that is to be
provided by
the broadcasting station. Also, the CAS software may also include other
supplemental
(or additional) information other than information associated with
authentication or de-
scrambling. The telematics terminal may also download the CAS software from
the
transmitting system, thereby upgrading the CAS software already stored in the
memory
card.
[2041 Similar to the telematics terminal shown in FIG. 11, the telematics
terminal of
FIG. 12 may also further include a storage unit 223 and a memory controller
224. Also,
the scrambled mobile broadcast service data that are received may also either
be
directly stored in the storage unit 223 without modification or be descrambled
and then
stored in the storage unit 223. Alternatively, the mobile broadcast service
data may
also be stored in a write/read medium inserted in the write/read media driver
104
instead of the storage unit 223. If the mobile broadcast service data stored
in the write/
read medium inserted in the write/read media driver 104 instead or in the
storage unit
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223 are scrambled, the corresponding data may be descrambled after an
authentication
process when being played (or reproduced).
[205] More specifically, also in FIG. 12, the mobile broadcast service data de-
multiplexed by the demultiplexer 216 may be outputted to the AN decoder 217 or
the
data decoder 218. Alternatively, based upon the control of the memory
controller 224,
the demultiplexed mobile broadcast service data may also be written (or
recorded) in
the storage unit 223. When the user selects one of instant recording, reserved
(or pre-
programmed) recording, and time shift, the memory controller 224 records the
cor-
responding mobile broadcast service data demultiplexed by the demultiplexer
216 in
the storage unit 223. Additionally, when the user selects the playback of the
mobile
broadcast service data stored in the storage unit 223, the mobile broadcast
service data
stored in the storage unit 223 is read and outputted based upon the control of
the
memory controller 224. Subsequently, after being decoded by the AN decoder 217
or
the data decoder 218, the decoded mobile broadcast service data may be
provided to
the user.
[206] The memory controller 224 may control the fast-forward, rewind, slow
motion,
and instant replay functions of the data that are stored in the storage unit
223. Herein,
the instant replay function corresponds to repeatedly viewing scenes that the
viewer (or
user) wishes to view once again. The instant replay function may be performed
on
stored data and also on data that are currently being received in real time by
as-
sociating the instant replay function with the time shift function. Also, when
the
memory controller 224 is provided with a scramble/descramble algorithm, the
memory
controller 224 may scramble the scrambled and received mobile broadcast
service data
once again, thereby storing the re-scrambled mobile broadcast service data in
the
storage unit 223. Alternatively, the memory controller 224 may scramble the
mobile
broadcast service data, which have not been scrambled, and store the scrambled
mobile
broadcast service data in the storage unit. Then, playing-back the data, the
memory
controller 224 may descramble the stored mobile broadcast data and output the
de-
scrambled data to the demultiplexer 216.
[207]
[208] MPH Frame Structure
[209] In the embodiment of the present invention, the mobile broadcast service
data
including traffic information are first multiplexed with main broadcast
service data in
MPH frame units and, then, modulated in a VSB mode and transmitted to the
receiving
system. At this point, one MPH frame consists of K1 number of sub-frames,
wherein
one sub-frame includes K2 number of slots. Also, each slot may be configured
of K3
number of data packets. In the embodiment of the present invention, K1 will be
set to
5, K2 will be set to 16, and K3 will be set to 156 (i.e., K1=5, K2=16, and
K3=156).
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The values for K1, K2, and K3 presented in this embodiment either correspond
to
values according to a preferred embodiment or are merely exemplary. Therefore,
the
above-mentioned values will not limit the scope of the present invention.
[2101 FIG. 13 illustrates a structure of a MPH frame for transmitting and
receiving mobile
broadcast service data according to the present invention. In the example
shown in
FIG. 13, one MPH frame consists of 5 sub-frames, wherein each sub-frame
includes 16
slots. In this case, the MPH frame according to the present invention includes
5 sub-
frames and 80 slots. Also, in a packet level, one slot is configured of 156
data packets
i.e., transport stream packets), and in a symbol level, one slot is configured
of 156 data
segments. Herein, the size of one slot corresponds to one half (1/2) of a VSB
field.
More specifically, since one 207-byte data packet has the same amount of data
as a
data segment, a data packet prior to being interleaved may also be used as a
data
segment. At this point, two VSB fields are grouped to form a VSB frame.
[2111 FIG. 14 illustrates an exemplary structure of a VSB frame, wherein one
VSB frame
consists of 2 VSB fields (i.e., an odd field and an even field). Herein, each
VSB field
includes a field synchronization segment and 312 data segments. The slot
corresponds
to a basic time period for multiplexing the mobile broadcast service data and
the main
broadcast service data. Herein, one slot may either include the mobile
broadcast
service data or be configured only of the main broadcast service data. If one
MPH
frame is transmitted during one slot, the first 118 data packets within the
slot
correspond to a data group. And, the remaining 38 data packets become the main
broadcast service data packets. In another example, when no data group exists
in a slot,
the corresponding slot is configured of 156 main broadcast service data
packets.
Meanwhile, when the slots are assigned to a VSB frame, an off-set exists for
each
assigned position.
[2121 FIG. 15 illustrates a mapping example of the positions to which the
first 4 slots of a
sub-frame are assigned with respect to a VSB frame in a space region. And,
FIG. 16 il-
lustrates a mapping example of the positions to which the first 4 slots of a
sub-frame
are assigned with respect to a VSB frame in a time region. Referring to FIG.
15 and
FIG. 16, a 38`h data packet (TS packet #37) of a 1St slot (Slot #0) is mapped
to the 1St
data packet of an odd VSB field. A 38t data packet (TS packet #37) of a 2nd
slot (Slot
#1) is mapped to the 157h data packet of an odd VSB field. Also, a 38`h data
packet
(TS packet #37) of a 3rd slot (Slot #2) is mapped to the 1 data packet of an
even VSB
field. And, a 38`h data packet (TS packet #37) of a 4`h slot (Slot #3) is
mapped to the
157`h data packet of an even VSB field. Similarly, the remaining 12 slots
within the
corresponding sub-frame are mapped in the subsequent VSB frames using the same
method.
[2131 Meanwhile, one data group may be divided into at least one or more
hierarchical
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regions. And, depending upon the characteristics of each hierarchical region,
the type
of mobile broadcast service data being inserted in each region may vary. For
example,
the data group within each region may be divided (or categorized) based upon
the
receiving performance. In an example given in the present invention, a data
group is
divided into regions A, B, C, and D in a data configuration prior to data
deinterleaving.
[2141 FIG. 17 illustrates an alignment of data after being data interleaved
and identified.
FIG. 18 illustrates an enlarged portion of the data group shown in FIG. 17 for
a better
understanding of the present invention. FIG. 19 illustrates an alignment of
data before
being data interleaved and identified. And, FIG. 20 illustrates an enlarged
portion of
the data group shown in FIG. 19 for a better understanding of the present
invention.
More specifically, a data structure identical to that shown in FIG. 17 is
transmitted to a
receiving system. In other words, one data packet is data-interleaved so as to
be
scattered to a plurality of data segments, thereby being transmitted to the
receiving
system. FIG. 17 illustrates an example of one data group being scattered to
170 data
segments. At this point, since one 207-byte packet has the same amount of data
as one
data segment, the packet that is not yet processed with data-interleaving may
be used
as the data segment.
[2151 FIG. 17 shows an example of dividing a data group prior to being data-
interleaved
into 10 MPH blocks (i.e., MPH block 1 (B 1) to MPH block 10 (B 10)). In this
example,
each MPH block has the length of 16 segments. Referring to FIG. 17, only the
RS
parity data are allocated to portions of the first 5 segments of the MPH block
1 (Bl)and
the last 5 segments of the MPH block 10 (B 10). The RS parity data are
excluded in
regions A to D of the data group. More specifically, when it is assumed that
one data
group is divided into regions A, B, C, and D, each MPH block may be included
in any
one of region A to region D depending upon the characteristic of each MPH
block
within the data group.
[2161 Herein, the data group is divided into a plurality of regions to be used
for different
purposes. More specifically, a region of the main broadcast service data
having no in-
terference or a very low interference level may be considered to have a more
resistant
(or stronger) receiving performance as compared to regions having higher
interference
levels. Additionally, when using a system inserting and transmitting known
data in the
data group, wherein the known data are known based upon an agreement between
the
transmitting system and the receiving system, and when consecutively long
known
data are to be periodically inserted in the mobile broadcast service data, the
known
data having a predetermined length may be periodically inserted in the region
having
no interference from the main broadcast service data (i.e., a region wherein
the main
broadcast service data are not mixed). However, due to interference from the
main
broadcast service data, it is difficult to periodically insert known data and
also to insert
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consecutively long known data to a region having interference from the main
broadcast
service data.
[217] Referring to FIG. 17, MPH block 4 (B4) to MPH block 7 (B7) correspond to
regions without interference of the main broadcast service data. MPH block 4
(B4) to
MPH block 7 (B7) within the data group shown in FIG. 17 correspond to a region
where no interference from the main broadcast service data occurs. In this
example, a
long known data sequence is inserted at both the beginning and end of each MPH
block. In the description of the present invention, the region including MPH
block 4
(B4) to MPH block 7 (B7) will be referred to as "region A (=B4+B5+B6+B7)". As
described above, when the data group includes region A having a long known
data
sequence inserted at both the beginning and end of each MPH block, the
receiving
system is capable of performing equalization by using the channel information
that can
be obtained from the known data. Therefore, the strongest equalizing
performance may
be yielded (or obtained) from one of region A to region D.
[218] In the example of the data group shown in FIG. 17, MPH block 3 (B3) and
MPH
block 8 (B8) correspond to a region having little interference from the main
broadcast
service data. Herein, a long known data sequence is inserted in only one side
of each
MPH block B3 and B8. More specifically, due to the interference from the main
broadcast service data, a long known data sequence is inserted at the end of
MPH
block 3 (B3), and another long known data sequence is inserted at the
beginning of
MPH block 8 (B8). In the present invention, the region including MPH block 3
(B3)
and MPH block 8 (B8) will be referred to as "region B(=B3+B8)". As described
above,
when the data group includes region B having a long known data sequence
inserted at
only one side (beginning or end) of each MPH block, the receiving system is
capable
of performing equalization by using the channel information that can be
obtained from
the known data. Therefore, a stronger equalizing performance as compared to
region
C/D may be yielded (or obtained).
[219] Referring to FIG. 17, MPH block 2 (B2) and MPH block 9 (B9) correspond
to a
region having more interference from the main broadcast service data as
compared to
region B. A long known data sequence cannot be inserted in any side of MPH
block 2
(B2) and MPH block 9 (B9). Herein, the region including MPH block 2 (B2) and
MPH
block 9 (B9) will be referred to as "region C(=B2+B9)". Finally, in the
example shown
in FIG. 17, MPH block 1 (B 1) and MPH block 10 (B 10) correspond to a region
having
more interference from the main broadcast service data as compared to region
C.
Similarly, a long known data sequence cannot be inserted in any side of MPH
block 1
(B 1) and MPH block 10 (B 10). Herein, the region including MPH block 1 (B 1)
and
MPH block 10 (B 10) will be referred to as "region D (=B 1+1310)". Since
region C/D is
spaced further apart from the known data sequence, when the channel
environment
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undergoes frequent and abrupt changes, the receiving performance of region C/D
may
be deteriorated.
[2201 FIG. 19 illustrates a data structure prior to data interleaving. More
specifically, FIG.
19 illustrates an example of 118 data packets being allocated to a data group.
FIG. 19
shows an example of a data group consisting of 118 data packets, wherein,
based upon
a reference packet (e.g., a 1 packet (or data segment) or 157`h packet (or
data segment)
after a field synchronization signal), when allocating data packets to a VSB
frame, 37
packets are included before the reference packet and 81 packets (including the
reference packet) are included afterwards. In other words, with reference to
FIG. 17, a
field synchronization signal is placed (or assigned) between MPH block 2 (B2)
and
MPH block 3 (B3). Accordingly, this indicates that the slot has an off-set of
37 data
packets with respect to the corresponding VSB field. The size of the data
groups,
number of hierarchical regions within the data group, the size of each region,
the
number of MPH blocks included in each region, the size of each MPH block, and
so on
described above are merely exemplary. Therefore, the present invention will
not be
limited to the examples described above.
[2211 FIG. 21 illustrates an exemplary assignement order of data groups being
assigned to
one of 5 sub-frames, wherein the 5 sub-frames configure an MPH frame. For
example,
the method of assigning data groups may be identically applied to all MPH
frames or
differently applied to each MPH frame. Furthermore, the method of assinging
data
groups may be identically applied to all sub-frames or differently applied to
each sub-
frame. At this point, when it is assumed that the data groups are assigned
using the
same method in all sub-frames of the corresponding MPH frame, the total number
of
data groups being assigned to an MPH frame is equal to a multiple of '5'.
According to
the embodiment of the present invention, a plurality of consecutive data
groups is
assigned to be spaced as far apart from one another as possible within the MPH
frame.
Thus, the system can be capable of responding promptly and effectively to any
burst
error that may occur within a sub-frame.
[2221 For example, when it is assumed that 3 data groups are assigned to a sub-
frame, the
data groups are assigned to a 1St slot (Slot #0), a 5`h slot (Slot #4), and a
9`h slot (Slot
#8) in the sub-frame, respectively. FIG. 21 illustrates an example of
assigning 16 data
groups in one sub-frame using the above-described pattern (or rule). In other
words,
each data group is serially assigned to 16 slots corresponding to the
following
numbers: 0, 8, 4, 12, 1, 9, 5, 13, 2, 10, 6, 14, 3, 11, 7, and 15. Equation 1
below shows
the above-described rule (or pattern) for assigning data groups in a sub-
frame.
[2231
[2241 Equation 1
[2251
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i = 4i + o mod 16
0=0 if, i<4,
0=2 else if i<8,
Herein,- 0=1 else if i<12!0
0=3 else.
[226] Herein, j indicates the slot number within a sub-frame. The value of j
may range
from 0 to 15 (i.e.,
D ) < 15
). Also, variable i indicates the data group number. The value of i may range
from 0 to
15 (i.e.,
U ~<15
)=
[227] In the present invention, a collection of data groups included in a MPH
frame will
be referred to as a "parade". Based upon the RS frame mode, the parade
transmits data
of at least one specific RS frame. The mobile broadcast service data within
one RS
frame may be assigned either to all of regions A/B/C/D within the
corresponding data
group, or to at least one of regions A/B/C/D. In the embodiment of the present
invention, the mobile broadcast service data within one RS frame may be
assigned
either to all of regions A/B/C/D, or to at least one of regions A/B and
regions C/D. If
the mobile broadcast service data are assigned to the latter case (i.e., one
of regions A/
B and regions C/D), the RS frame being assigned to regions A/B and the RS
frame
being assigned to regions C/D within the corresponding data group are
different from
one another.
[228] In the description of the present invention, the RS frame being assigned
to regions
A/B within the corresponding data group will be referred to as a "primary RS
frame",
and the RS frame being assigned to regions C/D within the corresponding data
group
will be referred to as a "secondary RS frame", for simplicity. Also, the
primary RS
frame and the secondary RS frame form (or configure) one parade. More
specifically,
when the mobile broadcast service data within one RS frame are assigned either
to all
of regions A/B/C/D within the corresponding data group, one parade transmits
one RS
frame. Conversely, when the mobile broadcast service data within one RS frame
are
assigned either to at least one of regions A/B and regions C/D, one parade may
transmit up to 2 RS frames. More specifically, the RS frame mode indicates
whether a
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parade transmits one RS frame, or whether the parade transmits two RS frames.
Table
1 below shows an example of the RS frame mode.
[2291
[2301 Table 1
RS frame mode(2 Description
bits)
00 There is only one primary RS frame for all group regions
01 There are two separate RS frames.- Primary RS frame for group
regions A and B- Secondary RS frame for group regions C and D
Reserved
11 Reserved
[2311
[2321 Table 1 illustrates an example of allocating 2 bits in order to indicate
the RS frame
mode. For example, referring to Table 1, when the RS frame mode value is equal
to
'00', this indicates that one parade transmits one RS frame. And, when the RS
frame
mode value is equal to '01', this indicates that one parade transmits two RS
frames, i.e.,
the primary RS frame and the secondary RS frame. More specifically, when the
RS
frame mode value is equal to '01', data of the primary RS frame for regions
A/B are
assigned and transmitted to regions A/B of the corresponding data group.
Similarly,
data of the secondary RS frame for regions C/D are assigned and transmitted to
regions
C/D of the corresponding data group.
[2331 Additionally, one RS frame transmits one ensemble. Herein, the ensemble
is a
collection of services requiring the same quality of service (QOS) and being
encoded
with the same FEC codes. More specifically, when one parade is configured of
one RS
frame, then one parade transmits one ensemble. Conversely, when one parade is
configured of two RS frames, i.e., when one parade is configured of a primary
RS
frame and a secondary RS frame, then one parade transmits two ensembles (i.e.,
a
primary ensemble and a secondary ensemble). More specifically, the primary
ensemble
is transmitted through a primary RS frame of a parade, and the secondary
ensemble is
transmitted through a secondary RS frame of a parade. The RS frame is a
2-dimensional data frame through which an ensemble is RS-CRC encoded.
[2341 As described in the assignment of data groups, the parades are also
assigned to be
spaced as far apart from one another as possible within the sub-frame. Thus,
the system
can be capable of responding promptly and effectively to any burst error that
may
occur within a sub-frame. Furthermore, the method of assinging parades may be
identically applied to all sub-frames or differently applied to each sub-
frame.
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According to the embodiment of the present invention, the parades may be
assigned
differently for each MPH frame and identically for all sub-frames within an
MPH
frame. More specifically, the MPH frame structure may vary by MPH frame units.
Thus, an ensemble rate may be adjusted on a more frequent and flexible basis.
[235] FIG. 22 illustrates an example of multiple data groups of a single
parade being
assigned (or allocated) to an MPH frame. More specifically, FIG. 22
illustrates an
example of a plurality of data groups included in a single parade, wherein the
number
of data groups included in a sub-frame is equal to '3', being allocated to an
MPH frame.
Referring to FIG. 22, 3 data groups are sequentially assigned to a sub-frame
at a cycle
period of 4 slots. Accordingly, when this process is equally performed in the
5 sub-
frames included in the corresponding MPH frame, 15 data groups are assigned to
a
single MPH frame. Herein, the 15 data groups correspond to data groups
included in a
parade. Therefore, since one sub-frame is configured of 4 VSB frame, and since
3 data
groups are included in a sub-frame, the data group of the corresponding parade
is not
assigned to one of the 4 VSB frames within a sub-frame.
[236] For example, when it is assumed that one parade transmits one RS frame,
and that a
RS frame encoder located in a later block performs RS-encoding on the
corresponding
RS frame, thereby adding 24 bytes of parity data to the corresponding RS frame
and
transmitting the processed RS frame, the parity data occupy approximately
11.37%
(=24/(187+24)x100) of the total code word length. Meanwhile, when one sub-
frame
includes 3 data groups, and when the data groups included in the parade are
assigned,
as shown in FIG. 22, a total of 15 data groups form an RS frame. Accordingly,
even
when an error occurs in an entire data group due to a burst noise within a
channel, the
percentile is merely 6.67% (=1/15x100). Therefore, the receiving system may
correct
all errors by performing an erasure RS decoding process. More specifically,
when the
erasure RS decoding is performed, a number of channel errors corresponding to
the
number of RS parity bytes may be corrected. By doing so, the receiving system
may
correct the error of at least one data group within one parade. Thus, the
minimum burst
noise length correctable by a RS frame is over 1 VSB frame.
[237] Meanwhile, when data groups of a parade are assigned as described above,
either
main broadcast service data may be assigned between each data group, or data
groups
corresponding to different parades may be assigned between each data group.
More
specifically, data groups corresponding to multiple parades may be assigned to
one
MPH frame. Basically, the method of assigning data groups corresponding to
multiple
parades is very similar to the method of assigning data groups corresponding
to a
single parade. In other words, data groups included in other parades that are
to be
assigned to an MPH frame are also respectively assigned according to a cycle
period of
4 slots. At this point, data groups of a different parade may be sequentially
assigned to
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the respective slots in a circular method. Herein, the data groups are
assigned to slots
starting from the ones to which data groups of the previous parade have not
yet been
assigned. For example, when it is assumed that data groups corresponding to a
parade
are assigned as shown in FIG. 22, data groups corresponding to the next parade
may be
assigned to a sub-frame starting either from the 12`x' slot of a sub-frame.
However, this
is merely exemplary. In another example, the data groups of the next parade
may also
be sequentially assigned to a different slot within a sub-frame at a cycle
period of 4
slots starting from the 3rd slot.
[2381 FIG. 23 illustrates an example of transmitting 3 parades (Parade #0,
Parade #1, and
Parade #2) to an MPH frame. More specifically, FIG. 23 illustrates an example
of
transmitting parades included in one of 5 sub-frames, wherein the 5 sub-frames
configure one MPH frame. When the 1s` parade (Parade #0) includes 3 data
groups for
each sub-frame, the positions of each data groups within the sub-frames may be
obtained by substituting values '0' to '2' for i in Equation 1. More
specifically, the data
groups of the 1s` parade (Parade #0) are sequentially assigned to the 1s`,
5`,, and 9`, slots
(Slot #0, Slot #4, and Slot #8) within the sub-frame. Also, when the 2d parade
includes
2 data groups for each sub-frame, the positions of each data groups within the
sub-
frames may be obtained by substituting values '3' and '4' for i in Equation 1.
More
specifically, the data groups of the 2d parade (Parade #1) are sequentially
assigned to
the 2d and 12t slots (Slot #3 and Slot #11) within the sub-frame. Finally,
when the 3rd
parade includes 2 data groups for each sub-frame, the positions of each data
groups
within the sub-frames may be obtained by substituting values '5' and '6' for i
in
Equation 1. More specifically, the data groups of the 3rd parade (Parade #2)
are se-
quentially assigned to the 7`h and 11t slots (Slot #6 and Slot #10) within the
sub-frame.
[2391 As described above, data groups of multiple parades may be assigned to a
single
MPH frame, and, in each sub-frame, the data groups are serially allocated to a
group
space having 4 slots from left to right. Therefore, a number of groups of one
parade per
sub-frame (NOG) may correspond to any one integer from '0' to W. Herein, since
one
MPH frame includes 5 sub-frames, the total number of data groups within a
parade that
can be allocated to an MPH frame may correspond to any one multiple of '5'
ranging
from '5' to '40'.
[2401 FIG. 24 illustrates an example of expanding the assignment process of 3
parades,
shown in FIG. 23, to 5 sub-frames within an MPH frame.
[2411
[2421 General Description of the Transmitting System
[2431 FIG. 25 illustrates a block diagram showing a general structure of a
digital
broadcast transmitting system according to an embodiment of the present
invention.
[2441 Herein, the digital broadcast transmitting includes a service
multiplexer 1100 and a
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transmitter 1200. Herein, the service multiplexer 1100 is located in the
studio of each
broadcast station, and the transmitter 1200 is located in a site placed at a
predetermined
distance from the studio. The transmitter 1200 may be located in a plurality
of different
locations. Also, for example, the plurality of transmitters may share the same
frequency. And, in this case, the plurality of transmitters receives the same
signal. Ac-
cordingly, in the receiving system, a channel equalizer may compensate signal
distortion, which is caused by a reflected wave, so as to recover the original
signal. In
another example, the plurality of transmitters may have different frequencies
with
respect to the same channel.
[245] The receiving system may become a telematics terminal, a mobile phone, a
terminal
for receiving mobile broadcast. PDA, and a notebook computer, and so on.
[246] A variety of methods may be used for data communication each of the
transmitters,
which are located in remote positions, and the service multiplexer. For
example, an
interface standard such as a synchronous serial interface for transport of
MPEG-2 data
(SMPTE-31OM). In the SMPTE-31OM interface standard, a constant data rate is
decided as an output data rate of the service multiplexer. For example, in
case of the
8VSB mode, the output data rate is 19.39 Mbps, and, in case of the 16VSB mode,
the
output data rate is 38.78 Mbps. Furthermore, in the conventional 8VSB mode
transmitting system, a transport stream (TS) packet having a data rate of
approximately
19.39 Mbps may be transmitted through a single physical channel. Also, in the
transmitting system according to the present invention provided with backward
com-
patibility with the conventional transmitting system, additional encoding is
performed
on the mobile broadcast service data. Thereafter, the additionally encoded
mobile
broadcast service data are multiplexed with the main broadcast service data to
a TS
packet form, which is then transmitted. At this point, the data rate of the
multiplexed
TS packet is approximately 19.39 Mbps.
[247] At this point, the service multiplexer 1100 receives at least one type
of mobile
broadcast service data and program specific information/program and system in-
formation protocol (PSI/PSIP) table data for each mobile broadcast service so
as to en-
capsulate the received data to each TS packet. Also, the service multiplexer
1100
receives at least one type of main broadcast service data and PSI/PSIP table
data for
each main broadcast service and encapsulates the received data to a transport
stream
(TS) packet. Subsequently, the TS packets are multiplexed according to a pre-
determined multiplexing rule and outputs the multiplexed packets to the
transmitter
1200.
[248]
[249] Service Multiplexer
[250] FIG. 26 illustrates a block diagram showing an example of the service
multiplexer.
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The service multiplexer includes a controller 1110 for controlling the overall
operations of the service multiplexer, a PSUPSIP generator 1120 for the main
broadcast service, a PSUPSIP generator 1130 for the mobile broadcast service,
a null
packet generator 1140, a mobile broadcast service multiplexer 1150, and a
transport
multiplexer 1160.
[251] The transport multiplexer 1160 may include a main broadcast service
multiplexer
1161 and a transport stream (TS) packet multiplexer 1162.
[252] Referring to FIG. 26, at least one type of compression encoded main
broadcast
service data and the PSUPSIP table data generated from the PSUPSIP generator
1120
for the main broadcast service are inputted to the main broadcast service
multiplexer
1161 of the transport multiplexer 1160. The main broadcast service multiplexer
1161
encapsulates each of the inputted main broadcast service data and PSUPSIP
table data
to MPEG-2 TS packet forms. Then, the MPEG-2 TS packets are multiplexed and
outputted to the TS packet multiplexer 1162. Herein, the data packet being
outputted
from the main broadcast service multiplexer 1161 will be referred to as a main
broadcast service data packet for simplicity.
[253] Thereafter, at least one type of the compression encoded mobile
broadcast service
data and the PSUPSIP table data generated from the PSUPSIP generator 1130 for
the
mobile broadcast service are inputted to the mobile broadcast service
multiplexer 1150.
[254] The mobile broadcast service multiplexer 1150 encapsulates each of the
inputted
mobile broadcast service data and PSI/PSIP table data to MPEG-2 TS packet
forms.
Then, the MPEG-2 TS packets are multiplexed and outputted to the TS packet
multiplexer 1162. Herein, the data packet being outputted from the mobile
broadcast
service multiplexer 1150 will be referred to as a mobile broadcast service
data packet
for simplicity.
[255] At this point, the transmitter 1200 requires identification information
in order to
identify and process the main broadcast service data packet and the mobile
broadcast
service data packet. Herein, the identification information may use values pre-
decided
in accordance with an agreement between the transmitting system and the
receiving
system, or may be configured of a separate set of data, or may modify
predetermined
location value with in the corresponding data packet.
[256] As an example of the present invention, a different packet identifier
(PID) may be
assigned to identify each of the main broadcast service data packet and the
mobile
broadcast service data packet.
[257] In another example, by modifying a synchronization data byte within a
header of
the mobile broadcast service data, the service data packet may be identified
by using
the synchronization data byte value of the corresponding service data packet.
For
example, the synchronization byte of the main broadcast service data packet
directly
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outputs the value decided by the ISO/IEC13818-1 standard (i.e., 0x47) without
any
modification. The synchronization byte of the mobile broadcast service data
packet
modifies and outputs the value, thereby identifying the main broadcast service
data
packet and the mobile broadcast service data packet. Conversely, the
synchronization
byte of the main broadcast service data packet is modified and outputted,
whereas the
synchronization byte of the mobile broadcast service data packet is directly
outputted
without being modified, thereby enabling the main broadcast service data
packet and
the mobile broadcast service data packet to be identified.
[2581 A plurality of methods may be applied in the method of modifying the syn-
chronization byte. For example, each bit of the synchronization byte may be
inversed,
or only a portion of the synchronization byte may be inversed.
[2591 As described above, any type of identification information may be used
to identify
the main broadcast service data packet and the mobile broadcast service data
packet.
Therefore, the scope of the present invention is not limited only to the
example set
forth in the description of the present invention.
[2601 Meanwhile, a transport multiplexer used in the conventional digital
broadcasting
system may be used as the transport multiplexer 1160 according to the present
invention. More specifically, in order to multiplex the mobile broadcast
service data
and the main broadcast service data and to transmit the multiplexed data, the
data rate
of the main broadcast service is limited to a data rate of (19.39-K) Mbps.
Then, K
Mbps, which corresponds to the remaining data rate, is assigned as the data
rate of the
mobile broadcast service. Thus, the transport multiplexer which is already
being used
may be used as it is without any modification.
[2611 Herein, the transport multiplexer 1160 multiplexes the main broadcast
service data
packet being outputted from the main broadcast service multiplexer 1161 and
the
mobile broadcast service data packet being outputted from the mobile broadcast
service multiplexer 1150. Thereafter, the transport multiplexer 1160 transmits
the
multiplexed data packets to the transmitter 1200.
[2621 However, in some cases, the output data rate of the mobile broadcast
service
multiplexer 1150 may not be equal to K Mbps. In this case, the mobile
broadcast
service multiplexer 1150 multiplexes and outputs null data packets generated
from the
null packet generator 1140 so that the output data rate can reach K Mbps. More
specifically, in order to match the output data rate of the mobile broadcast
service
multiplexer 1150 to a constant data rate, the null packet generator 1140
generates null
data packets, which are then outputted to the mobile broadcast service
multiplexer
1150.
[2631 For example, when the service multiplexer 1100 assigns K Mbps of the
19.39 Mbps
to the mobile broadcast service data, and when the remaining (19.39-K) Mbps
is,
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therefore, assigned to the main broadcast service data, the data rate of the
mobile
broadcast service data that are multiplexed by the service multiplexer 1100
actually
becomes lower than K Mbps. This is because, in case of the mobile broadcast
service
data, the pre-processor of the transmitting system performs additional
encoding,
thereby increasing the amount of data. Eventually, the data rate of the mobile
broadcast
service data, which may be transmitted from the service multiplexer 1100,
becomes
smaller than K Mbps.
[264] For example, since the pre-processor of the transmitter performs an
encoding
process on the mobile broadcast service data at a coding rate of at least 1/2,
the amount
of the data outputted from the pre-processor is increased to more than twice
the amount
of the data initially inputted to the pre-processor. Therefore, the sum of the
data rate of
the main broadcast service data and the data rate of the mobile broadcast
service data,
both being multiplexed by the service multiplexer 1100, becomes either equal
to or
smaller than 19.39 Mbps.
[265] Therefore, in order to match the data rate of the data that are finally
outputted from
the service multiplexer 1100 to a constant data rate (e.g., 19.39 Mbps), an
amount of
null data packets corresponding to the amount of lacking data rate is
generated from
the null packet generator 1140 and outputted to the mobile broadcast service
multiplexer 1150.
[266] Accordingly, the mobile broadcast service multiplexer 1150 encapsulates
each of
the mobile broadcast service data and the PSI/PSIP table data that are being
inputted to
a MPEG-2 TS packet form. Then, the above-described TS packets are multiplexed
with the null data packets and, then, outputted to the TS packet multiplexer
1162.
[267] Thereafter, the TS packet multiplexer 1162 multiplexes the main
broadcast service
data packet being outputted from the main broadcast service multiplexer 1161
and the
mobile broadcast service data packet being outputted from the mobile broadcast
service multiplexer 1150 and transmits the multiplexed data packets to the
transmitter
1200 at a data rate of 19.39 Mbps.
[268] According to an embodiment of the present invention, the mobile
broadcast service
multiplexer 1150 receives the null data packets. However, this is merely
exemplary
and does not limit the scope of the present invention. In other words,
according to
another embodiment of the present invention, the TS packet multiplexer 1162
may
receive the null data packets, so as to match the data rate of the finally
outputted data
to a constant data rate. Herein, the output path and multiplexing rule of the
null data
packet is controlled by the controller 1110. The controller 1110 controls the
mul-
tiplexing processed performed by the mobile broadcast service multiplexer
1150, the
main broadcast service multiplexer 1161 of the transport multiplexer 1160, and
the TS
packet multiplexer 1162, and also controls the null data packet generation of
the null
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packet generator 1140. At this point, the transmitter 1200 discards the null
data packets
transmitted from the service multiplexer 1100 instead of transmitting the null
data
packets.
[269] Further, in order to allow the transmitter 1200 to discard the null data
packets
transmitted from the service multiplexer 1100 instead of transmitting them,
iden-
tification information for identifying the null data packet is required.
Herein, the iden-
tification information may use values pre-decided in accordance with an
agreement
between the transmitting system and the receiving system. For example, the
value of
the synchronization byte within the header of the null data packet may be
modified so
as to be used as the identification information. Alternatively, a transport-
error
_indicator flag may also be used as the identification information.
[270] In the description of the present invention, an example of using the
transport_error_indicator flag as the identification information will be given
to
describe an embodiment of the present invention. In this case, the
transport_error_indicator flag of the null data packet is set to 'I', and the
transport_error_indicator flag of the remaining data packets are reset to '0',
so as to
identify the null data packet. More specifically, when the null packet
generator 1140
generates the null data packets, if the transport_error_indicator flag from
the header
field of the null data packet is set to 'I' and then transmitted, the null
data packet may
be identified and, therefore, be discarded. In the present invention, any type
of iden-
tification information for identifying the null data packets may be used.
Therefore, the
scope of the present invention is not limited only to the examples set forth
in the de-
scription of the present invention.
[271] According to another embodiment of the present invention, a transmission
parameter may be included in at least a portion of the null data packet, or at
least one
table or an operations and maintenance (OM) packet (or OMP) of the PSI/PSIP
table
for the mobile broadcast service. In this case, the transmitter 1200 extracts
the
transmission parameter and outputs the extracted transmission parameter to the
cor-
responding block and also transmits the extracted parameter to the receiving
system if
required. More specifically, a packet referred to as an OMP is defined for the
purpose
of operating and managing the transmitting system. For example, the OMP is
configured in accordance with the MPEG-2 TS packet format, and the
corresponding
PID is given the value of Ox1FFA. The OMP is configured of a 4-byte header and
a
184-byte payload. Herein, among the 184 bytes, the first byte corresponds to
an
OM_type field, which indicates the type of the OM packet.
[272] In the present invention, the transmission parameter may be transmitted
in the form
of an OMP. And, in this case, among the values of the reserved fields within
the
OM_type field, a pre-arranged value is used, thereby indicating that the
transmission
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parameter is being transmitted to the transmitter 1200 in the form of an OMP.
More
specifically, the transmitter 1200 may find (or identify) the OMP by referring
to the
PID. Also, by parsing the OM_type field within the OMP, the transmitter 1200
can
verify whether a transmission parameter is included after the OM_type field of
the cor-
responding packet. The transmission parameter corresponds to supplemental data
required for processing mobile broadcast service data from the transmitting
system and
the receiving system.
[273] The transmission parameter corresponds to supplemental data required for
processing mobile broadcast service data from the transmitting system and the
receiving system. Herein, the transmission parameter may include data group in-
formation, region information within the data group, block information, RS
frame in-
formation, super frame information, MPH frame information, parade information,
ensemble information, information associated with serial concatenated
convolution
code (SCCC), and RS code information. The significance of some information
within
the transmission parameters has already been described in detail. Descriptions
of other
information that have not yet been described will be in detail in a later
process.
[274] The transmission parameter may also include information on how signals
of a
symbol domain are encoded in order to transmit the mobile broadcast service
data, and
multiplexing information on how the main broadcast service data and the mobile
broadcast service data or various types of mobile broadcast service data are
multiplexed.
[275] The information included in the transmission parameter are merely
exemplary to
facilitate the understanding of the present invention. And, the adding and
deleting of
the information included in the transmission parameter may be easily modified
and
changed by anyone skilled in the art. Therefore, the present invention is not
limited to
the examples proposed in the description set forth herein.
[276] Furthermore, the transmission parameters may be provided from the
service
multiplexer 1100 to the transmitter 1200. Alternatively, the transmission
parameters
may also be set up by an internal controller (not shown) within the
transmitter 1200 or
received from an external source.
[277]
[278] Transmitter
[279]
[280] *FIG. 27 illustrates a block diagram showing an example of the
transmitter 1200
according to an embodiment of the present invention. Herein, the transmitter
1200
includes a controller 1205, a demultiplexer 1210, a packet jitter mitigator
1220, a pre-
processor 1230, a packet multiplexer 1240, a post-processor 1250, a
synchronization
(sync) multiplexer 1260, and a transmission unit 1270. Herein, when a data
packet is
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received from the service multiplexer 1100, the demultiplexer 1210 should
identify
whether the received data packet corresponds to a main broadcast service data
packet,
a mobile broadcast service data packet, or a null data packet. For example,
the de-
multiplexer 1210 uses the PID within the received data packet so as to
identify the
main broadcast service data packet and the mobile broadcast service data
packet. Then,
the demultiplexer 1210 uses a transport _error _indicator field to identify
the null data
packet. The main broadcast service data packet identified by the demultiplexer
1210 is
outputted to the packet jitter mitigator 1220, the mobile broadcast service
data packet
is outputted to the pre-processor 1230, and the null data packet is discarded.
If a
transmission parameter is included in the null data packet, then the
transmission
parameter is first extracted and outputted to the corresponding block.
Thereafter, the
null data packet is discarded.
[2811 The pre-processor 1230 performs an additional encoding process of the
mobile
broadcast service data included in the service data packet, which is
demultiplexed and
outputted from the demultiplexer 1210. The pre-processor 1230 also performs a
process of configuring a data group so that the data group may be positioned
at a
specific place in accordance with the purpose of the data, which are to be
transmitted
on a transmission frame. This is to enable the mobile broadcast service data
to respond
swiftly and strongly against noise and channel changes. The pre-processor 1230
may
also refer to the transmission parameter when performing the additional
encoding
process. Also, the pre-processor 1230 groups a plurality of mobile broadcast
service
data packets to configure a data group. Thereafter, known data, mobile
broadcast
service data, RS parity data, and MPEG header are allocated to pre-determined
regions
within the data group.
[2821
[2831 Pre-processor within Transmitter
[2841 FIG. 28 illustrates a block diagram showing the structure of a pre-
processor 1230
according to the present invention. Herein, the pre-processor 1230 includes an
MPH
frame encoder 1301, a block processor 1302, a group formatter 1303, a
signaling
encoder 1304, and a packet encoder 1304. The MPH frame encoder 1301, which is
included in the pre-processor 1230 having the above-described structure, data-
randomizes the mobile broadcast service data that are inputted to the
demultiplexer
1210, thereby creating a RS frame. Then, the MPH frame encoder 1301 performs
an
encoding process for error correction in RS frame units. The MPH frame encoder
1301
may include at least one RS frame encoder. More specifically, RS frame
encoders may
be provided in parallel, wherein the number of RS frame encoders is equal to
the
number of parades within the MPH frame. As described above, the MPH frame is a
basic time cycle period for transmitting at least one parade. Also, each
parade consists
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of one or two RS frames.
[285] FIG. 29 illustrates a conceptual block diagram of the MPH frame encoder
1301
according to an embodiment of the present invention. The MPH frame encoder
1301
includes an input demultiplexer (DEMUX) 1309, M number of RS frame encoders
1310 to 131M-1, and an output multiplexer (MUX) 1320. Herein, M represent the
number of parades included in one MPH frame. The input demultiplexer (DEMUX)
1309 splits input ensembles. Then, the split input ensembles decide the RS
frame to
which the ensembles are to be inputted. Thereafter, the inputted ensembles are
outputted to the respective RS frame. At this point, an ensemble may be mapped
to
each RS frame encoder or parade. For example, when one parade configures one
RS
frame, the ensembles, RS frames, and parades may each be mapped to be in a one
-
to-one (1:1) correspondence with one another. More specifically, the data in
one
ensemble configure a RS frame. And, a RS frame is divided into a plurality of
data
groups. Based upon the RS frame mode of Table 1, the data within one RS frame
may
be assigned either to all of regions A/B/C/D within multiple data groups, or
to at least
one of regions A/B and regions C/D within multiple data groups.
[286] When the RS frame mode value is equal to '01' i.e., when the data of the
primary RS
frame are assigned to regions A/B of the corresponding data group and data of
the
secondary RS frame are assigned to regions C/D of the corresponding data
group, each
RS frame encoder creates a primary RS frame and a secondary RS frame for each
parade. Conversely, when the RS frame mode value is equal to '00', when the
data of
the primary RS frame are assigned to all of regions A/B/C/D, each RS frame
encoder
creates a RS frame (i.e., a primary RS frame) for each parade. Also, each RS
frame
encoder divides each RS frame into several portions. Each portion of the RS
frame is
equivalent to a data amount that can be transmitted by a data group.
[287] The output multiplexer (MUX) 1320 multiplexes portions within M number
of RS
frame encoders 1310 to 131M-1 are multiplexed and then outputted to the block
processor 1302. For example, if one parade transmits two RS frames, portions
of
primary RS frames within M number of RS frame encoders 1310 to 131 M-1 are
multiplexed and outputted. Thereafter, portions of secondary RS frames within
M
number of RS frame encoders 1310 to 131M-1 are multiplexed and transmitted.
The
input demultiplexer (DEMUX) 1309 and the output multiplexer (MUX) 1320 operate
based upon the control of the control unit 1205. The control unit 1205 may
provide
necessary (or required) FEC modes to each RS frame encoder. The FEC mode
includes
the RS code mode, which will be described in detail in a later process.
[288] FIG. 30 illustrates a detailed block diagram of an RS frame encoder
among a
plurality of RS frame encoders within an MPH frame encoder. One RS frame
encoder
may include a primary encoder 1410 and a secondary encoder 1420. Herein, the
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secondary encoder 1420 may or may not operate based upon the RS frame mode.
For
example, when the RS frame mode value is equal to '00', as shown in Table 1,
the
secondary encoder 1420 does not operate. The primary encoder 1410 may include
a
data randomizer 1411, a Reed-Solomon-cyclic redundancy check (RS-CRC) encoder
1412, and a RS frame divider 1413. And, the secondary encoder 1420 may also
include
a data randomizer 1421, a RS-CRC encoder 1422, and a RS frame divider 1423.
[2891 More specifically, the data randomizer 1411 of the primary encoder 1410
receives
mobile broadcast service data of a primary ensemble outputted from the output
de-
multiplexer (DEMUX) 1309. Then, after randomizing the received mobile
broadcast
service data, the data randomizer 1411 outputs the randomized data to the RS-
CRC
encoder 1412. At this point, since the data randomizer 1411 performs the
randomizing
process on the mobile broadcast service data, the randomizing process that is
to be
performed by the data randomizer 1251 of the post-processor 1250 on the mobile
broadcast service data may be omitted. The data randomizer 1411 may also
discard the
synchronization byte within the mobile broadcast service data packet and
perform the
randomizing process. This is an option that may be chosen by the system
designer. In
the example given in the present invention, the randomizing process is
performed
without discarding the synchronization byte within the corresponding mobile
broadcast
service data packet.
[2901 The RS-CRC encoder 1412 uses at least one of a Reed-Solomon (RS) code
and a
cyclic redundancy check (CRC) code, so as to perform forward error collection
(FEC)
encoding on the randomized primary ensemble, thereby forming a primary RS
frame.
Therefore, the RS-CRC encoder 1412 outputs the newly formed primary RS frame
to
the RS frame divider 1413. The RS-CRC encoder 1412 groups a plurality of
mobile
broadcast service data packets that is randomized and inputted, so as to
create a RS
frame. Then, the RS-CRC encoder 1412 performs at least one of an error
correction
encoding process and an error detection encoding process in RS frame units. Ac-
cordingly, robustness may be provided to the mobile broadcast service data,
thereby
scattering group error that may occur during changes in a frequency
environment,
thereby enabling the mobile broadcast service data to respond to the frequency
en-
vironment, which is extremely vulnerable and liable to frequent changes. Also,
the RS-
CRC encoder 1412 groups a plurality of RS frame so as to create a super frame,
thereby performing a row permutation process in super frame units. The row
permutation process may also be referred to as a "row interleaving process".
Hereinafter, the process will be referred to as "row permutation" for
simplicity.
[2911 More specifically, when the RS-CRC encoder 1412 performs the process of
permuting each row of the super frame in accordance with a pre-determined
rule, the
position of the rows within the super frame before and after the row
permutation
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process is changed. If the row permutation process is performed by super frame
units,
and even though the section having a plurality of errors occurring therein
becomes
very long, and even though the number of errors included in the RS frame,
which is to
be decoded, exceeds the extent of being able to be corrected, the errors
become
dispersed within the entire super frame. Thus, the decoding ability is even
more
enhanced as compared to a single RS frame.
[2921 At this point, as an example of the present invention, RS-encoding is
applied for the
error correction encoding process, and a cyclic redundancy check (CRC)
encoding is
applied for the error detection process in the RS-CRC encoder 1412. When
performing
the RS-encoding, parity data that are used for the error correction are
generated. And,
when performing the CRC encoding, CRC data that are used for the error
detection are
generated. The CRC data generated by CRC encoding may be used for indicating
whether or not the mobile broadcast service data have been damaged by the
errors
while being transmitted through the channel. In the present invention, a
variety of error
detection coding methods other than the CRC encoding method may be used, or
the
error correction coding method may be used to enhance the overall error
correction
ability of the receiving system. Herein, the RS-CRC encoder 1412 refers to a
pre-
determined transmission parameter provided by the control unit 1205 and/or a
transmission parameter provided from the service multiplexer 1100 so as to
perform
operations including RS frame configuration, RS encoding, CRC encoding, super
frame configuration, and row permutation in super frame units.
[2931 FIG. 31 illustrates a process of one or two RS frame being divided into
several
portions, based upon an RS frame mode value, and a process of each portion
being
assigned to a corresponding region within the respective data group. More
specifically,
FIG. 31(a) shows an example of the RS frame mode value being equal to '00'.
Herein,
only the primary encoder 1410 of FIG. 30 operates, thereby forming one RS
frame for
one parade. Then, the RS frame is divided into several portions, and the data
of each
portion are assigned to regions A/B/C/D within the respective data group. FIG.
31(b)
shows an example of the RS frame mode value being equal to '01'. Herein, both
the
primary encoder 1410 and the secondary encoder 1420 of FIG. 30 operate,
thereby
forming two RS frames for one parade, i.e., one primary RS frame and one
secondary
RS frame. Then, the primary RS frame is divided into several portions, and the
secondary RS frame is divided into several portions. At this point, the data
of each
portion of the primary RS frame are assigned to regions A/B within the
respective data
group. And, the data of each portion of the secondary RS frame are assigned to
regions
C/D within the respective data group.
[2941
[2951 Detailed Description of the RS Frame
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[296] FIG. 32(a) illustrates an example of an RS frame being generated from
the RS-CRC
encoder 1412 according to the present invention. According to this embodiment,
in the
RS frame, the length of a column (i.e., number of rows) is set to 187 bytes,
and the
length of a row (i.e., number of column) is set to N bytes. At this point, the
value of N,
which corresponds to the number of columns within an RS frame, can be decided
according to Equation 2.
[297] Equation 2
[298]
N- 5xNoGxPL 2
187+P
[299] Herein, NoG indicates the number of data groups assigned to a sub-frame.
PL
represents the number of SCCC payload data bytes assigned to a data group.
And, P
signifies the number of RS parity data bytes added to each column of the RS
frame.
Finally,
[x]
is the greatest integer that is equal to or smaller than X.
[300] More specifically, in Equation 2, PL corresponds to the length of an RS
frame
portion. The value of PL is equivalent to the number of SCCC payload data
bytes that
are assigned to the corresponding data group. Herein, the value of PL may vary
depending upon the RS frame mode, SCCC block mode, and SCCC outer code mode.
Table 2 to Table 5 below respectively show examples of PL values, which vary
in
accordance with the RS frame mode, SCCC block mode, and SCCC outer code mode.
The SCCC block mode and the SCCC outer code mode will be described in detail
in a
later process.
[301]
[302] Table 2
SCCC outer code mode PL
for Region A for Region B for Region C for Region D
00 00 00 00 9624
00 00 00 01 9372
00 00 01 00 8886
00 00 01 01 8634
00 01 00 00 8403
00 01 00 01 8151
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00 01 01 00 7665
00 01 01 01 7413
01 00 00 00 7023
01 00 00 01 6771
01 00 01 00 6285
01 00 01 01 6033
01 01 00 00 5802
01 01 00 01 5550
01 01 01 00 5064
01 01 01 01 4812
Others Reserved
[303]
[304] Table 2 shows an example of the PL values for each data group within an
RS
frame, wherein each PL value varies depending upon the SCCC outer code mode,
when the RS frame mode value is equal to '00', and when the SCCC block mode
value
is equal to '00'. For example, when it is assumed that each SCCC outer code
mode
value of regions A/B/C/D within the data group is equal to '00' (i.e., the
block
processor 1302 of a later block performs encoding at a coding rate of 1/2),
the PL
value within each data group of the corresponding RS frame may be equal to
9624
bytes. More specifically, 9624 bytes of mobile broadcast service data within
one RS
frame may be assigned to regions A/B/C/D of the corresponding data group.
[305]
[306] Table 3
SCCC outer code mode PL
00 9624
01 4812
Others Reserved
[307]
[308] Table 3 shows an example of the PL values for each data group within an
RS frame,
wherein each PL value varies depending upon the SCCC outer code mode, when the
RS frame mode value is equal to '00', and when the SCCC block mode value is
equal
to '01'.
[309]
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[310] Table 4
SCCC outer code mode PL
for Region A for Region B
00 00 7644
00 01 6423
01 00 5043
01 01 3822
Others Reserved
[311]
[312] Table 4 shows an example of the PL values for each data group within a
primary
RS frame, wherein each PL value varies depending upon the SCCC outer code
mode,
when the RS frame mode value is equal to '01', and when the SCCC block mode
value
is equal to '00'. For example, when each SCCC outer code mode value of regions
A/B
is equal to '00', 7644 bytes of mobile broadcast service data within a primary
RS frame
may be assigned to regions A/B of the corresponding data group.
[313]
[314] Table 5
SCCC outer code mode PL
for Region C for Region D
00 00 1980
00 01 1728
01 00 1242
01 01 990
Others Reserved
[315]
[316] Table 5 shows an example of the PL values for each data group within a
secondary
RS frame, wherein each PL value varies depending upon the SCCC outer code
mode,
when the RS frame mode value is equal to '01', and when the SCCC block mode
value
is equal to '00'. For example, when each SCCC outer code mode value of regions
C/D
is equal to '00', 1980 bytes of mobile broadcast service data within a
secondary RS
frame may be assigned to regions C/D of the corresponding data group.
[317] According to the embodiment of the present invention, the value of N is
equal to or
greater than 187 (i.e.,
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1S7
). More specifically, the RS frame of FIG. 32(a) has the size of
N(row)x187(column)
bytes. More specifically, the RS-CRC encoder 1412 first divides the inputted
mobile
broadcast service data bytes to units of a predetermined length. The
predetermined
length is decided by the system designer. And, in the example of the present
invention,
the predetermined length is equal to 187 bytes, and, therefore, the 187-byte
unit will be
referred to as a "packet" for simplicity. For example, the inputted mobile
broadcast
service data may correspond either to an MPEG transport stream (TS) packet
configured of 188-byte units or to an IP datagram. Alternatively, the IP
datagram may
be encapsulated to a TS packet of 188-byte units and, then, inputted.
[3181 When the mobile broadcast service data that are being inputted
correspond to a
MPEG transport packet stream configured of 188-byte units, the first
synchronization
byte is removed so as to configure a 187-byte unit. Then, N number of packets
are
grouped to form an RS frame. Herein, the synchronization byte is removed
because
each mobile broadcast service data packet has the same value. Meanwhile, when
the
input mobile broadcast service data of the RS frame do not correspond to the
MPEG
TS packet format, the mobile broadcast service data are inputted N number of
times in
187-byte units without being processed with the removing of the MPEG syn-
chronization byte, thereby creating a RS frame.
[3191 In addition, when the input data format of the RS frame supports both
the input data
corresponding to the MPEG TS packet and the input data not corresponding to
the
MPEG TS packet, such information may be included in a transmission parameter
transmitted from the service multiplexer 1100, thereby being sent to the
transmitter
1200. Accordingly, the RS-CRC encoder 1412 of the transmitter 1200 receives
this in-
formation to be able to control whether or not to perform the process of
removing the
MPEG synchronization byte. Also, the transmitter provides such information to
the
receiving system so as to control the process of inserting the MPEG
synchronization
byte that is to be performed by the RS frame decoder of the receiving system.
Herein,
the process of removing the synchronization byte may be performed during a
randomizing process of the data randomizer 1411 in an earlier process. In this
case, the
process of the removing the synchronization byte by the RS-CRC encoder 1412
may
be omitted.
[3201 Moreover, when adding synchronization bytes from the receiving system,
the
process may be performed by the data derandomizer instead of the RS frame
decoder.
Therefore, if a removable fixed byte (e.g., synchronization byte) does not
exist within
the mobile broadcast service data packet that is being inputted to the RS-CRC
encoder
1412, or if the mobile broadcast service data that are being inputted are not
configured
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in a packet format, the mobile broadcast service data that are being inputted
are
divided into 187-byte units, thereby configuring a packet for each 187-byte
unit.
[3211 Subsequently, N number of packets configured of 187 bytes is grouped to
configure
a RS frame. At this point, the RS frame is configured as a RS frame having the
size of
N(row)x187(column) bytes, in which 187-byte packets are sequentially inputted
in a
row direction. More specifically, each of the N number of columns included in
the RS
frame includes 187 bytes. When the RS frame is created, as shown in FIG.
32(a), the
RS-CRC encoder 1412 performs a (Nc,Kc)-RS encoding process on each column, so
as to generate Nc-Kc(=P) number of parity bytes. Then, the RS-CRC encoder 1412
adds the newly generated P number of parity bytes after the very last byte of
the cor-
responding column, thereby creating a column of (187+P) bytes. Herein, as
shown in
FIG. 32(a), Kc is equal to 187 (i.e., Kc=187), and Nc is equal to 187+P (i.e.,
Nc=187+P). Herein, the value of P may vary depending upon the RS code mode.
Table
6 below shows an example of an RS code mode, as one of the RS encoding in-
formation.
[3221
[3231 Table 6
RS code mode RS code Number of Parity Bytes (P)
00 (211,187) 24
01 (223,187) 36
(235,187) 48
11 Reserved Reserved
[3241
[3251 Table 6 shows an example of 2 bits being assigned in order to indicate
the RS code
mode. The RS code mode represents the number of parity bytes corresponding to
the
RS frame. For example, when the RS code mode value is equal to '10',
(235,187)-RS-encoding is performed on the RS frame of FIG. 32(a), so as to
generate
48 parity data bytes. Thereafter, the 48 parity bytes are added after the last
data byte of
the corresponding column, thereby creating a column of 235 data bytes. When
the RS
frame mode value is equal to '00' in Table 1 (i.e., when the RS frame mode
indicates a
single RS frame), only the RS code mode of the corresponding RS frame is
indicated.
However, when the RS frame mode value is equal to 'O1' in Table 1 (i.e., when
the RS
frame mode indicates multiple RS frames), the RS code mode corresponding to a
primary RS frame and a secondary RS frame. More specifically, it is preferable
that the
RS code mode is independently applied to the primary RS frame and the
secondary RS
frame.
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[326] When such RS encoding process is performed on all N number of columns, a
RS
frame having the size of N(row)x(187+P)(column) bytes may be created, as shown
in
FIG. 32(b). Each row of the RS frame is configured of N bytes. However,
depending
upon channel conditions between the transmitting system and the receiving
system,
error may be included in the RS frame. When errors occur as described above,
CRC
data (or CRC code or CRC checksum) may be used on each row unit in order to
verify
whether error exists in each row unit. The RS-CRC encoder 1412 may perform CRC
encoding on the mobile broadcast service data being RS encoded so as to create
(or
generate) the CRC data. The CRC data being generated by CRC encoding may be
used
to indicate whether the mobile broadcast service data have been damaged while
being
transmitted through the channel.
[327] The present invention may also use different error detection encoding
methods
other than the CRC encoding method. Alternatively, the present invention may
use the
error correction encoding method to enhance the overall error correction
ability of the
receiving system. FIG. 32(c) illustrates an example of using a 2-byte (i.e.,
16-bit) CRC
checksum as the CRC data. Herein, a 2-byte CRC checksum is generated for N
number
of bytes of each row, thereby adding the 2-byte CRC checksum at the end of the
N
number of bytes. Thus, each row is expanded to (N+2) number of bytes. Equation
3
below corresponds to an exemplary equation for generating a 2-byte CRC
checksum
for each row being configured of N number of bytes.
[328]
[329] Equation 3
[330]
g(x) = x16 +x12 +x5 +1
[331] The process of adding a 2-byte checksum in each row is only exemplary.
Therefore,
the present invention is not limited only to the example proposed in the
description set
forth herein. As described above, when the process of RS encoding and CRC
encoding
are completed, the (Nx187)-byte RS frame is expanded to a (N+2)x(187+P)-byte
RS
frame. Based upon an error correction scenario of a RS frame expanded as
described
above, the data bytes within the RS frame are transmitted through a channel in
a row
direction. At this point, when a large number of errors occur during a limited
period of
transmission time, errors also occur in a row direction within the RS frame
being
processed with a decoding process in the receiving system. However, in the
perspective of RS encoding performed in a column direction, the errors are
shown as
being scattered. Therefore, error correction may be performed more
effectively. At this
point, a method of increasing the number of parity data bytes (P) may be used
in order
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to perform a more intense error correction process. However, using this method
may
lead to a decrease in transmission efficiency. Therefore, a mutually
advantageous
method is required. Furthermore, when performing the decoding process, an
erasure
decoding process may be used to enhance the error correction performance.
[332] Additionally, the RS-CRC encoder 1412 according to the present invention
also
performs a row permutation (or interleaving) process in super frame units in
order to
further enhance the error correction performance when error correction the RS
frame.
FIG. 33(a) to FIG. 33(d) illustrates an example of performing a row
permutation
process in super frame units according to the present invention. More
specifically, G
number of RS frames RS-CRC-encoded is grouped to form a super frame, as shown
in
FIG. 33(a). At this point, since each RS frame is formed of (N+2)x(187+P)
number of
bytes, one super frame is configured to have the size of (N+2)x(187+P)xG
bytes.
[333] When a row permutation process permuting each row of the super frame
configured
as described above is performed based upon a pre-determined permutation rule,
the
positions of the rows prior to and after being permuted (or interleaved)
within the super
frame may be altered. More specifically, the i`, row of the super frame prior
to the in-
terleaving process, as shown in FIG. 33(b), is positioned in the jt' row of
the same
super frame after the row permutation process, as shown in FIG. 33(c). The
above-
described relation between i and j can be easily understood with reference to
a
permutation rule as shown in Equation 4 below.
[334]
[335] Equation 4
[336]
j = G(imod(187+P))+Li1(187+P)J
i = (187+P)(jmodG)+[ j/GJ
where 0-i, j<_(187 + P)G - 1; or
where 0:-<i, j < (187 + P)G
[337] Herein, each row of the super frame is configured of (N+2) number of
data bytes
even after being row-permuted in super frame units.
[338] When all row permutation processes in super frame units are completed,
the super
frame is once again divided into G number of row-permuted RS frames, as shown
in
FIG. 33(d), and then provided to the RS frame divider 1413. Herein, the number
of RS
parity bytes and the number of columns should be equally provided in each of
the RS
frames, which configure a super frame. As described in the error correction
scenario of
a RS frame, in case of the super frame, a section having a large number of
error
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occurring therein is so long that, even when one RS frame that is to be
decoded
includes an excessive number of errors (i.e., to an extent that the errors
cannot be
corrected), such errors are scattered throughout the entire super frame.
Therefore, in
comparison with a single RS frame, the decoding performance of the super frame
is
more enhanced.
[3391 The above description of the present invention corresponds to the
processes of
forming (or creating) and encoding an RS frame, when a data group is divided
into
regions A/B/C/D, and when data of an RS frame are assigned to all of regions
A/B/C/D
within the corresponding data group. More specifically, the above description
corresponds to an embodiment of the present invention, wherein one RS frame is
transmitted using one parade. In this embodiment, the secondary encoder 1420
does
not operate (or is not active).
[3401
[3411 *Meanwhile, 2 RS frames are transmitting using one parade, the data of
the primary
RS frame may be assigned to regions A/B within the data group and be
transmitted,
and the data of the secondary RS frame may be assigned to regions C/D within
the data
group and be transmitted. At this point, the primary encoder 1410 receives the
mobile
broadcast service data that are to be assigned to regions A/B within the data
group, so
as to form the primary RS frame, thereby performing RS-encoding and CRC-
encoding.
Similarly, the secondary encoder 1420 receives the mobile broadcast service
data that
are to be assigned to regions C/D within the data group, so as to form the
secondary RS
frame, thereby performing RS-encoding and CRC-encoding. More specifically, the
primary RS frame and the secondary RS frame are created independently.
[3421 FIG. 34 illustrates examples of receiving the mobile broadcast service
data that are
to be assigned to regions A/B within the data group, so as to form the primary
RS
frame, and receives the mobile broadcast service data that are to be assigned
to regions
C/D within the data group, so as to form the secondary RS frame, thereby
performing
error correction encoding and error detection encoding on each of the first
and
secondary RS frames. More specifically, FIG. 34(a) illustrates an example of
the RS-
CRC encoder 1412 of the primary encoder 1410 receiving mobile broadcast
service
data of the primary ensemble that are to be assigned to regions A/B within the
cor-
responding data group, so as to create an RS frame having the size of
N 1(row)x 187 (column). Then, in this example, the primary encoder 1410
performs RS-
encoding on each column of the RS frame created as described above, thereby
adding
P1 number of parity data bytes in each column. Finally, the primary encoder
1410
performs CRC-encoding on each row, thereby adding a 2-byte checksum in each
row.
[3431 FIG. 34(b) illustrates an example of the RS-CRC encoder 1422 of the
secondary
encoder 1420 receiving mobile broadcast service data of the secondary ensemble
that
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are to be assigned to regions C/D within the corresponding data group, so as
to create
an RS frame having the size of N2(row)x187(column). Then, in this example, the
secondary encoder 1420 performs RS-encoding on each column of the RS frame
created as described above, thereby adding P2 number of parity data bytes in
each
column. Finally, the secondary encoder 1420 performs CRC-encoding on each row,
thereby adding a 2-byte checksum in each row. At this point, each of the RS-
CRC
encoders 1412 and 1422 may refer to a pre-determined transmission parameter
provided by the control unit 1205 and/or a transmission parameter provided
from the
service multiplexer 1100, the RS-CRC encoders 1412 and 1422 may be informed of
RS frame information (including RS frame mode), RS encoding information
(including
RS code mode), SCCC information (including SCCC block information and SCCC
outer code mode), data group information, and region information within a data
group.
The RS-CRC encoders 1412 and 1422 may refer to the transmission parameters for
the
purpose of RS frame configuration, error correction encoding, error detection
encoding. Furthermore, the transmission parameters should also be transmitted
to the
receiving system so that the receiving system can perform a normal decoding
process.
[3441 The data of the primary RS frame, which is encoded by RS frame units and
row-
permuted by super frame units from the RS-CRC encoder 1412 of the primary
encoder
1410, are outputted to the RS frame divider 1413. If the secondary encoder
1420 also
operates in the embodiment of the present invention, the data of the secondary
RS
frame, which is encoded by RS frame units and row-permuted by super frame
units
from the RS-CRC encoder 1422 of the secondary encoder 1420, are outputted to
the
RS frame divider 1423. The RS frame divider 1413 of the primary encoder 1410
divides the primary RS frame into several portions, which are then outputted
to the
output multiplexer (MUX) 1320. Each portion of the primary RS frame is
equivalent to
a data amount that can be transmitted by one data group. Similarly, the RS
frame
divider 1423 of the secondary encoder 1420 divides the secondary RS frame into
several portions, which are then outputted to the output multiplexer (MUX)
1320.
[3451 Hereinafter, the RS frame divider 1413 of the primary RS encoder 1410
will now be
described in detail. Also, in order to simplify the description of the present
invention, it
is assumed that an RS frame having the size of N(row)x187(column), as shown in
FIG.
32(a) to FIG. 32(c), that P number of parity data bytes are added to each
column by
RS-encoding the RS frame, and that a 2-byte checksum is added to each row by
CRC-
encoding the RS frame. Accordingly, the RS frame divider 1413 divides (or
partitions)
the encoded RS frame having the size of (N+2) (row)x 187 (column) into several
portions, each having the size of PL (wherein PL corresponds to the length of
the RS
frame portion).
[3461 At this point, as shown in Table 2 to Table 5, the value of PL may vary
depending
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upon the RS frame mode, SCCC block mode, and SCCC outer coder mode. Also, the
total number of data bytes of the RS-encoded and CRC-encoded RS frame is equal
to
or smaller than
5x NoG xPL
In this case, the RS frame is divided (or partitioned) into
((5xNo G)
number of portions each having the size of PL and one portion having a size
equal to
smaller than PL. More specifically, with the exception of the last portion of
the RS
frame, each of the remaining portions of the RS frame has an equal size of PL.
If the
size of the last portion is smaller than PL, a stuffing byte (or dummy byte)
may be
inserted in order to fill (or replace) the lacking number of data bytes,
thereby enabling
the last portion of the RS frame to also be equal to PL. Each portion of an RS
frame
corresponds to the amount of data that are to be SCCC-encoded and mapped into
a
single data group of a parade.
[347] FIG. 35(a) and FIG. 35(b) respectively illustrate examples of adding S
number of
stuffing bytes, when an RS frame having the size of (N+2)(row)x(187+P)(column)
is
divided into
o
xNoG
number of portions, each having the size of PL. More specifically, the RS-
encoded and
CRC-encoded RS frame, shown in FIG. 35(a), is divided into several portions,
as
shown in FIG. 35(b). The number of divided portions at the RS frame is equal
to
(5 xM )
Particularly, the first
(( x No )-1)
number of portions each has the size of PL, and the last portion of the RS
frame may
be equal to or smaller than PL. If the size of the last portion is smaller
than PL, a
stuffing byte (or dummy byte) may be inserted in order to fill (or replace)
the lacking
number of data bytes, as shown in Equation 5 below, thereby enabling the last
portion
of the RS frame to also be equal to PL.
[348]
[349] Equation 5
[350]
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S=(5xN0GxPL)-((N+2)x(187+P))
[3511 Herein, each portion including data having the size of PL passes through
the output
multiplexer 1320 of the MPH frame encoder 1301, which is then outputted to the
block
processor 1302.
[3521 At this point, the mapping order of the RS frame portions to a parade of
data groups
in not identical with the group assignment order defined in Equation 1. When
given the
group positions of a parade in an MPH frame, the SCCC-encoded RS frame
portions
will be mapped in a time order (i.e., in a left-to-right direction). For
example, as shown
in FIG. 23, data groups of the 2d parade (Parade #1) are first assigned (or
allocated) to
the 13ffi slot (Slot #12) and then assigned to the 3rd slot (Slot #2).
However, when the
data are actually placed in the assigned slots, the data are placed in a time
sequence (or
time order, i.e., in a left-to-right direction). More specifically, the 1s`
data group of
Parade #1 is placed in Slot #2, and the 2nd data group of Parade #1 is placed
in Slot
#12.
[3531
[3541 Block Processor
[3551 Meanwhile, the block processor 1302 performs an SCCC outer encoding
process on
the output of the MPH frame encoder 1301. More specifically, the block
processor
1302 receives the data of each error correction encoded portion. Then, the
block
processor 1302 encodes the data once again at a coding rate of 1/H (wherein H
is an
integer equal to or greater than 2 (i.e.,
H> 2
), thereby outputting the 1/H-rate encoded data to the group formatter 1303.
According
to the embodiment of the present invention, the input data are encoded either
at a
coding rate of 1/2 (also referred to as "1/2-rate encoding") or at a coding
rate of 1/4
(also referred to as "1/4-rate encoding"). The data of each portion outputted
from the
MPH frame encoder 1301 may include at least one of pure mobile broadcast
service
data, RS parity data, CRC data, and stuffing data. However, in a broader
meaning, the
data included in each portion may correspond to data for mobile broadcast
services.
Therefore, the data included in each portion will all be considered as mobile
broadcast
service data and described accordingly.
[3561 The group formatter 1303 inserts the mobile broadcast service data SCCC-
outer-encoded and outputted from the block processor 1302 in the corresponding
region within the data group, which is formed in accordance with a pre-defined
rule.
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Also, in association with the data deinterleaving process, the group formatter
1303
inserts various place holders (or known data place holders) in the
corresponding region
within the data group. Thereafter, the group formatter 1303 deinterleaves the
data
within the data group and the place holders.
[357] According to the present invention, with reference to data after being
data-
interleaved, as shown in FIG. 17, a data groups is configured of 10 MPH blocks
(B 1 to
B 10) and divided into 4 regions (A, B, C, and D). Also, as shown in FIG. 17,
when it is
assumed that the data group is divided into a plurality of hierarchical
regions, as
described above, the block processor 1302 may encode the mobile broadcast
service
data, which are to be inserted to each region based upon the characteristic of
each hi-
erarchical region, at different coding rates. For example, the block processor
1302 may
encode the mobile broadcast service data, which are to be inserted in region
A/B
within the corresponding data group, at a coding rate of 1/2. Then, the group
formatter
1303 may insert the 1/2-rate encoded mobile broadcast service data to region
A/B.
Also, the block processor 1302 may encode the mobile broadcast service data,
which
are to be inserted in region C/D within the corresponding data group, at a
coding rate
of 1/4 having higher (or stronger) error correction ability than the 1/2-
coding rate.
Thereafter, the group formatter 1303 may insert the 1/2-rate encoded mobile
broadcast
service data to region C/D. In another example, the block processor 1302 may
encode
the mobile broadcast service data, which are to be inserted in region C/D, at
a coding
rate having higher error correction ability than the 1/4-coding rate. Then,
the group
formatter 1303 may either insert the encoded mobile broadcast service data to
region
C/D, as described above, or leave the data in a reserved region for future
usage.
[358] According to another embodiment of the present invention, the block
processor
1302 may perform a 1/H-rate encoding process in SCCC block units. Herein, the
SCCC block includes at least one MPH block. At this point, when 1/H-rate
encoding is
performed in MPH block units, the MPH blocks (B 1 to B 10) and the SCCC block
(SCB 1 to SCB 10) become identical to one another (i.e., SCB 1=B 1, SCB2=B2,
SCB3=B31 SCB4=B4, SCB5=B51 SCB6=B6, SCB7=B71 SCB8=B8, SCB9=B9, and
SCB 10=B 10). For example, the MPH block 1 (B 1) may be encoded at the coding
rate
of 1/2, the MPH block 2 (B2) may be encoded at the coding rate of 1/4, and the
MPH
block 3 (B3) may be encoded at the coding rate of 1/2. The coding rates are
applied re-
spectively to the remaining MPH blocks.
[359] Alternatively, a plurality of MPH blocks within regions A, B, C, and D
may be
grouped into one SCCC block, thereby being encoded at a coding rate of 1/H in
SCCC
block units. Accordingly, the receiving performance of region C/D may be
enhanced.
For example, MPH block 1 (B1) to MPH block 5 (B5) may be grouped into one SCCC
block and then encoded at a coding rate of 1/2. Thereafter, the group
formatter 1303
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may insert the 1/2-rate encoded mobile broadcast service data to a section
starting from
MPH block 1 (B1) to MPH block 5 (B5). Furthermore, MPH block 6 (B6) to MPH
block 10 (B 10) may be grouped into one SCCC block and then encoded at a
coding
rate of 1/4. Thereafter, the group formatter 1303 may insert the 1/4-rate
encoded
mobile broadcast service data to another section starting from MPH block 6
(B6) to
MPH block 10 (B 10). In this case, one data group may consist of two SCCC
blocks.
[3601 According to another embodiment of the present invention, one SCCC block
may
be formed by grouping two MPH blocks. For example, MPH block 1 (B 1) and MPH
block 6 (B6) may be grouped into one SCCC block (SCB1). Similarly, MPH block 2
(B2) and MPH block 7 (B7) may be grouped into another SCCC block (SCB2). Also,
MPH block 3 (B3) and MPH block 8 (B8) may be grouped into another SCCC block
(SCB3). And, MPH block 4 (B4) and MPH block 9 (B9) may be grouped into another
SCCC block (SCB4). Furthermore, MPH block 5 (B5) and MPH block 10 (B 10) may
be grouped into another SCCC block (SCB5). In the above-described example, the
data
group may consist of 10 MPH blocks and 5 SCCC blocks. Accordingly, in a data
(or
signal) receiving environment undergoing frequent and severe channel changes,
the
receiving performance of regions C and D, which is relatively more
deteriorated than
the receiving performance of region A, may be reinforced. Furthermore, since
the
number of mobile broadcast service data symbols increases more and more from
region A to region D, the error correction encoding performance becomes more
and
more deteriorated. Therefore, when grouping a plurality of MPH block to form
one
SCCC block, such deterioration in the error correction encoding performance
may be
reduced.
[3611 As described-above, when the block processor 1302 performs encoding at a
1/H-coding rate, information associated with SCCC should be transmitted to the
receiving system in order to accurately recover the mobile broadcast service
data.
Table 7 below shows an example of a SCCC block mode, which indicating the
relation
between an MPH block and an SCCC block, among diverse SCCC block information.
[3621
[3631 Table 7
SCCC BlockMode 00 01 10 11
Description One MPH Two MPH Reserved Reserved
Block per Blocks per
SCCC Block SCCC Block
SCB SCB SCB
input,MPH input,MPH
Block Blocks
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SCB1 B1 B1 +B6
SCB2 B2 B2 + B7
SCB3 B3 B3 + B8
SCB4 B4 B4 + B9
SCB5 B5 B5 + B 10
SCB6 B6 -
SCB7 B7 -
SCB8 B8 -
SCB9 B9 -
SCB10 B10 -
[364]
[365] More specifically, Table 4 shows an example of 2 bits being allocated in
order to
indicate the SCCC block mode. For example, when the SCCC block mode value is
equal to '00', this indicates that the SCCC block and the MPH block are
identical to one
another. Also, when the SCCC block mode value is equal to '01', this indicates
that
each SCCC block is configured of 2 MPH blocks.
[366] As described above, if one data group is configured of 2 SCCC blocks,
although it
is not indicated in Table 7, this information may also be indicated as the
SCCC block
mode. For example, when the SCCC block mode value is equal to '10', this
indicates
that each SCCC block is configured of 5 MPH blocks and that one data group is
configured of 2 SCCC blocks. Herein, the number of MPH blocks included in an
SCCC block and the position of each MPH block may vary depending upon the
settings made by the system designer. Therefore, the present invention will
not be
limited to the examples given herein. Accordingly, the SCCC mode information
may
also be expanded.
[367] An example of a coding rate information of the SCCC block, i.e., SCCC
outer code
mode, is shown in Table 8 below.
[368]
[369] Table 8
SCCC outercode mode (2 Description
bits)
00 Outer code rate of SCCC block is 1/2 rate
01 Outer code rate of SCCC block is 1/4 rate
Reserved
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11 Reserved
[370]
[371] More specifically, Table 8 shows an example of 2 bits being allocated in
order to
indicate the coding rate information of the SCCC block. For example, when the
SCCC
outer code mode value is equal to '00', this indicates that the coding rate of
the cor-
responding SCCC block is 1/2. And, when the SCCC outer code mode value is
equal
to '01', this indicates that the coding rate of the corresponding SCCC block
is 1/4.
[372] If the SCCC block mode value of Table 7 indicates '00', the SCCC outer
code mode
may indicate the coding rate of each MPH block with respect to each MPH block.
In
this case, since it is assumed that one data group includes 10 MPH blocks and
that 2
bits are allocated for each SCCC block mode, a total of 20 bits are required
for
indicating the SCCC block modes of the 10 MPH modes. In another example, when
the SCCC block mode value of Table 7 indicates '00', the SCCC outer code mode
may
indicate the coding rate of each region with respect to each region within the
data
group. In this case, since it is assumed that one data group includes 4
regions (i.e.,
regions A, B, C, and D) and that 2 bits are allocated for each SCCC block
mode, a total
of 8 bits are required for indicating the SCCC block modes of the 4 regions.
In another
example, when the SCCC block mode value of Table 7 is equal to '01', each of
the
regions A, B, C, and D within the data group has the same SCCC outer code
mode.
[373] Meanwhile, an example of an SCCC output block length (SOBL) for each
SCCC
block, when the SCCC block mode value is equal to '00', is shown in Table 9
below.
[374]
[375] Table 9
SCCC Block SOBL SIBL
1/2 rate 1/4 rate
SCB 1 (B 1) 528 264 132
SCB2 (B2) 1536 768 384
SCB3 (B3) 2376 1188 594
SCB4 (134) 2388 1194 597
SCB5 (B5) 2772 1386 693
SCB6 (B6) 2472 1236 618
SCB7 (B7) 2772 1386 693
SCB8 (B8) 2508 1254 627
SCB9 (B9) 1416 708 354
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SCB 10 (B 10) 480 240 120
[376]
[377] More specifically, when given the SCCC output block length (SOBL) for
each
SCCC block, an SCCC input block length (SIBL) for each corresponding SCCC
block
may be decided based upon the outer coding rate of each SCCC block. The SOBL
is
equivalent to the number of SCCC output (or outer-encoded) bytes for each SCCC
block. And, the SIBL is equivalent to the number of SCCC input (or payload)
bytes for
each SCCC block. Table 10 below shows an example of the SOBL and SIBL for each
SCCC block, when the SCCC block mode value is equal to '01'.
[378]
[379] Table 10
SCCC Block SOBL SIBL
1/2 rate 1/4 rate
SCB 1 (131+136) 528 264 132
SCB2 (B2+B7) 1536 768 384
SCB3 (B3+B8) 2376 1188 594
SCB4 (B4+B9) 2388 1194 597
SCB5 (135+1310) 2772 1386 693
[380]
[381] In order to do so, as shown in FIG. 36, the block processor 1302
includes a RS
frame portion-SCCC block converter 1511, a byte-bit converter 1512, a
convolution
encoder 1513, a symbol interleaver 1514, a symbol-byte converter 1515, and an
SCCC
block-MPH block converter 1516. The convolutional encoder 1513 and the symbol
in-
terleaver 1514 are virtually concatenated with the trellis encoding module in
the post-
processor in order to configure an SCCC block. More specifically, the RS frame
portion-SCCC block converter 1511 divides the RS frame portions, which are
being
inputted, into multiple SCCC blocks using the SIBL of Table 9 and Table 10
based
upon the RS code mode, SCCC block mode, and SCCC outer code mode. Herein, the
MPH frame encoder 1301 may output only primary RS frame portions or both
primary
RS frame portions and secondary RS frame portions in accordance with the RS
frame
mode.
[382] When the RS Frame mode is set to '00', a portion of the primary RS Frame
equal to
the amount of data, which are to be SCCC outer encoded and mapped to 10 MPH
blocks (B 1 to B 10) of a data group, will be provided to the block processor
1302.
When the SCCC block mode value is equal to '00', then the primary RS frame
portion
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will be split into 10 SCCC Blocks according to Table 9. Alternatively, when
the SCCC
block mode value is equal to '01', then the primary RS frame will be split
into 5 SCCC
blocks according to Table 10.
[3831 When the RS frame mode value is equal to '01', then the block processor
1302 may
receive two RS frame portions. The RS frame mode value of '01' will not be
used with
the SCCC block mode value of '01'. The first portion from the primary RS frame
will
be SCCC-outer-encoded as SCCC Blocks SCB3, SCB4, SCB5, SCB6, SCB7, and
SCB8 by the block processor 1302. The SCCC Blocks SCB3 and SCB8 will be
mapped to region B and the SCCC blocks SCB4, SCB5, SCB6, and SCB7 shall be
mapped to region A by the group formatter 1303. The second portion from the
secondary RS frame will also be SCCC-outer-encoded, as SCB 1, SCB2, SCB9, and
SCB 10, by the block processor 1302. The group formatter 1303 will map the
SCCC
blocks SCB 1 and SCB 10 to region D as the MPH blocks B 1 and B 10,
respectively.
Similarly, the SCCC blocks SCB2 and SCB9 will be mapped to region C as the MPH
blocks B2 and B9.
[3841 The byte-bit converter 1512 identifies the mobile broadcast service data
bytes of
each SCCC block outputted from the RS frame portion-SCCC block converter 1511
as
data bits, which are then outputted to the convolution encoder 1513. The
convolution
encoder 1513 performs one of 1/2-rate encoding and 1/4-rate encoding on the
inputted
mobile broadcast service data bits.
[3851 FIG. 37 illustrates a detailed block diagram of the convolution encoder
1513. The
convolution encoder 1513 includes two delay units 1521 and 1523 and three
adders
1522, 1524, and 1525. Herein, the convolution encoder 1513 encodes an input
data bit
U and outputs the coded bit U to 5 bits (u0 to u4). At this point, the input
data bit U is
directly outputted as uppermost bit uO and simultaneously encoded as lower bit
u1u2u3u4 and then outputted. More specifically, the input data bit U is
directly
outputted as the uppermost bit uO and simultaneously outputted to the first
and third
adders 1522 and 1525.
[3861 The first adder 1522 adds the input data bit U and the output bit of the
first delay
unit 1521 and, then, outputs the added bit to the second delay unit 1523.
Then, the data
bit delayed by a pre-determined time (e.g., by 1 clock) in the second delay
unit 1523 is
outputted as a lower bit u 1 and simultaneously fed-back to the first delay
unit 1521.
The first delay unit 1521 delays the data bit fed-back from the second delay
unit 1523
by a pre-determined time (e.g., by 1 clock). Then, the first delay unit 1521
outputs the
delayed data bit as a lower bit u2 and, at the same time, outputs the fed-back
data to the
first adder 1522 and the second adder 1524. The second adder 1524 adds the
data bits
outputted from the first and second delay units 1521 and 1523 and outputs the
added
data bits as a lower bit u3. The third adder 1525 adds the input data bit U
and the
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output of the second delay unit 1523 and outputs the added data bit as a lower
bit u4.
[387] At this point, the first and second delay units 1521 and 1523 are reset
to '0', at the
starting point of each SCCC block. The convolution encoder 1513 of FIG. 37 may
be
used as a 1/2-rate encoder or a 1/4-rate encoder. More specifically, when a
portion of
the output bit of the convolution encoder 1513, shown in FIG. 37, is selected
and
outputted, the convolution encoder 1513 may be used as one of a 1/2-rate
encoder and
a 1/4-rate encoder. Table 11 below shown an example of output symbols of the
convolution encoder 1513.
[388]
[389] Table 11
Region 1/2 rate 1/4 rate
SCCC block mode= '00' SCCC block mode= 'O 1'
A, B (u0, ul) (u0, u2), (u I, u3) (u0, u2), (u I, u4)
C, D (u0, ul), (u3, u4)
[390]
[391] For example, at the 1/2-coding rate, 1 output symbol (i.e., u0 and ul
bits) may be
selected and outputted. And, at the 1/4-coding rate, depending upon the SCCC
block
mode, 2 output symbols (i.e., 4 bits) may be selected and outputted. For
example, when
the SCCC block mode value is equal to '01', and when an output symbol
configured of
u0 and u2 and another output symbol configured of ul and u4 are selected and
outputted, a 1/4-rate coding result may be obtained.
[392] The mobile broadcast service data encoded at the coding rate of 1/2 or
1/4 by the
convolution encoder 1513 are outputted to the symbol interleaver 1514. The
symbol
interleaver 1514 performs block interleaving, in symbol units, on the output
data
symbol of the convolution encoder 1513. More specifically, the symbol
interleaver
1514 is a type of block interleaver. Any interleaver performing structural
rear-
rangement (or realignment) may be applied as the symbol interleaver 1514 of
the block
processor. However, in the present invention, a variable length symbol
interleaver that
can be applied even when a plurality of lengths is provided for the symbol, so
that its
order may be rearranged, may also be used.
[393] FIG. 38 illustrates a symbol interleaver according to an embodiment of
the present
invention. Particularly, FIG. 38 illustrates an example of the symbol
interleaver when
B=2112 and L=4096. Herein, B indicates a block length in symbols that are
outputted
for symbol interleaving from the convolution encoder 1513. And, L represents a
block
length in symbols that are actually interleaved by the symbol interleaver
1514. At this
point, the block length in symbols B inputted to the symbol interleaver 1514
is
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equivalent to
4 x `OBL
More specifically, since one symbol is configured of 2 bits, the value of B
may be set
to be equal to
4 x CBL
[394] In the present invention, when performing the symbol-intereleaving
process, the
conditions of
L_2m
(wherein m is an integer) and of
LAB
should be satisfied. If there is a difference in value between B and L, (L-B)
number of
null (or dummy) symbols is added, thereby creating an interleaving pattern, as
shown
in P'(i) of FIG. 38. Therefore, B becomes a block size of the actual symbols
that are
inputted to the symbol interleaver 1514 in order to be interleaved. L becomes
an in-
terleaving unit when the interleaving process is performed by an interleaving
pattern
created from the symbol interleaver 1514.
[395] Math figure 6 shown below describes the process of sequentially
receiving B
number of symbols, the order of which is to be rearranged, and obtaining an L
value
satisfying the conditions of
L = `1m
(wherein m is an integer) and of
L B
thereby creating the interleaving so as to realign (or rearrange) the symbol
order.
[396]
[397] Equation 6
[398]
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In relation to all places, wherein O <_ i <_ B -1,
Pt (i) _ {89 x i x (i +1) / 2 modL
Herein, L ~:B , L = 2'n, wherein m is an integer.
[399] As shown in P'(i) of FIG. 38, the order of B number of input symbols and
(L-B)
number of null symbols is rearranged by using the above-mentioned Equation 6.
Then,
as shown in P(i) of FIG. 38, the null byte places are removed, so as to
rearrange the
order. Starting with the lowest value of i, the P(i) are shifted to the left
in order to fill
the empty entry locations. Thereafter, the symbols of the aligned interleaving
pattern
P(i) are outputted to the symbol-byte converter 1515 in order. Herein, the
symbol-byte
converter 1515 converts to bytes the mobile broadcast service data symbols,
having the
rearranging of the symbol order completed and then outputted in accordance
with the
rearranged order, and thereafter outputs the converted bytes to the SCCC block-
MPH
block converter 1516. The SCCC block-MPH block converter 1516 converts the
symbol-interleaved SCCC blocks to MPH blocks, which are then outputted to the
group formatter 1303.
[400] If the SCCC block mode value is equal to '00', the SCCC block is mapped
at a one-
to-one (1:1) correspondence with each MPH block within the data group. In
another
example, if the SCCC block mode value is equal to '01', each SCCC block is
mapped
with two MPH blocks within the data group. For example, the SCCC block SCB 1
is
mapped with (B1, B6), the SCCC block SCB2 is mapped with (B2, B7), the SCCC
block SCB3 is mapped with (B3, B8), the SCCC block SCB4 is mapped with (B4,
B9),
and the SCCC block SCB5 is mapped with (B5, B 10). The MPH block that is
outputted from the SCCC block-MPH block converter 1516 is configured of mobile
broadcast service data and FEC redundancy. In the present invention, the
mobile
broadcast service data as well as the FEC redundancy of the MPH block will be
col-
lectively considered as mobile broadcast service data.
[4011
[402] Group Formatter
[403] The group formatter 1303 inserts data of MPH blocks outputted from the
block
processor 1302 to the corresponding MPH blocks within the data group, which is
formed in accordance with a pre-defined rule. Also, in association with the
data-
deinterleaving process, the group formatter 1303 inserts various place holders
(or
known data place holders) in the corresponding region within the data group.
More
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specifically, apart from the encoded mobile broadcast service data outputted
from the
block processor 1302, the group formatter 1303 also inserts MPEG header place
holders, non-systematic RS parity place holders, main broadcast service data
place
holders, which are associated with the data deinterleaving in a later process,
as shown
in FIG. 17.
[4041 Herein, the main broadcast service data place holders are inserted
because the
mobile broadcast service data bytes and the main broadcast service data bytes
are al-
ternately mixed with one another in regions B to D based upon the input of the
data
deinterleaver, as shown in FIG. 17. For example, based upon the data outputted
after
data deinterleaving, the place holder for the MPEG header may be allocated at
the very
beginning of each packet. Also, in order to configure an intended group
format,
dummy bytes may also be inserted. Furthermore, the group formatter 1303
inserts
place holders for initializing the trellis encoding module 1256 in the
corresponding
regions. For example, the initialization data place holders may be inserted in
the
beginning of the known data sequence. Additionally, the group formatter 1303
may
also insert signaling information, which are encoded and outputted from the
signaling
encoder 1304, in corresponding regions within the data group. At this point,
reference
may be made to the signaling information when the group formatter 1303 inserts
each
data type and respective place holders in the data group. The process of
encoding the
signaling information and inserting the encoded signaling information to the
data
group will be described in detail in a later process.
[4051 After inserting each data type and respective place holders in the data
group, the
group formatter 1303 may deinterleave the data and respective place holders,
which
have been inserted in the data group, as an inverse process of the data
interleaver,
thereby outputting the deinterleaved data and respective place holders to the
packet
encoder 1304. More specifically, when the data and respective place holders
within the
data group, which is configured (or structured) as shown in FIG. 17, are
deinterleaved
by the group formatter 1303 and outputted to the packet encoder 1304, the
structure of
the data group may be identical to the structure shown in FIG. 19. In order to
do so, the
group formatter 1303 may include a group format organizer 1527, and a data
dein-
terleaver 1529, as shown in FIG. 39. The group format organizer 1527 inserts
data and
respective place holders in the corresponding regions within the data group,
as
described above. And, the data deinterleaver 1529 deinterleaves the inserted
data and
respective place holders as an inverse process of the data interleaver.
[4061 The packet encoder 1304 removes the main broadcast service data place
holders
and the RS parity place holders that were allocated for the deinterleaving
process from
the deinterleaved data being inputted. Then, the packet encoder 1304 groups
the
remaining portion and inserts the 3-byte MPEG header place holder in an MPEG
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header having a null packet PID (or an unused PID from the main broadcast
service
data packet). Furthermore, the packet encoder 1304 adds a synchronization data
byte at
the beginning of each 187-byte data packet. Also, when the group formatter
1303
inserts known data place holders, the packet formatter 1303 may insert actual
known
data in the known data place holders, or may directly output the known data
place
holders without any modification in order to make replacement insertion in a
later
process. Thereafter, the packet encoder 1304 identifies the data within the
packet-
formatted data group, as described above, as a 188-byte unit mobile broadcast
service
data packet (i.e., MPEG TS packet), which is then provided to the packet
multiplexer
1240.
[407] Based upon the control of the control unit 1205, the packet multiplexer
1240
multiplexes the data group packet-formatted and outputted from the packet
formatter
306 and the main broadcast service data packet outputted from the packet
jitter
mitigator 1220. Then, the packet multiplexer 1240 outputs the multiplexed data
packets to the data randomizer 1251 of the post-processor 1250. More
specifically, the
control unit 1205 controls the time-multiplexing of the packet multiplexer
1240. If the
packet multiplexer 1240 receives 118 mobile broadcast service data packets
from the
packet encoder 1304, 37 mobile broadcast service data packets are placed
before a
place for inserting VSB field synchronization. Then, the remaining 81 mobile
broadcast service data packets are placed after the place for inserting VSB
field syn-
chronization. The multiplexing method may be adjusted by diverse variables of
the
system design. The multiplexing method and multiplexing rule of the packet
multiplexer 1240 will be described in more detail in a later process.
[408] Also, since a data group including mobile broadcast service data in-
between the
data bytes of the main broadcast service data is multiplexed (or allocated)
during the
packet multiplexing process, the shifting of the chronological position (or
place) of the
main broadcast service data packet becomes relative. Also, a system object
decoder
i.e., MPEG decoder) for processing the main broadcast service data of the
receiving
system, receives and decodes only the main broadcast service data and
recognizes the
mobile broadcast service data packet as a null data packet.
[409] Therefore, when the system object decoder of the receiving system
receives a main
broadcast service data packet that is multiplexed with the data group, a
packet jitter
occurs.
[410] At this point, since a multiple-level buffer for the video data exists
in the system
object decoder and the size of the buffer is relatively large, the packet
jitter generated
from the packet multiplexer 1240 does not cause any serious problem in case of
the
video data. However, since the size of the buffer for the audio data in the
object
decoder is relatively small, the packet jitter may cause considerable problem.
More
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specifically, due to the packet jitter, an overflow or underflow may occur in
the buffer
for the main broadcast service data of the receiving system (e.g., the buffer
for the
audio data). Therefore, the packet jitter mitigator 1220 re-adjusts the
relative position
of the main broadcast service data packet so that the overflow or underflow
does not
occur in the system object decoder.
[4111 In the present invention, examples of repositioning places for the audio
data packets
within the main broadcast service data in order to minimize the influence on
the
operations of the audio buffer will be described in detail. The packet jitter
mitigator
1220 repositions the audio data packets in the main broadcast service data
section so
that the audio data packets of the main broadcast service data can be as
equally and
uniformly aligned and positioned as possible. Additionally, when the positions
of the
main broadcast service data packets are relatively re-adjusted, associated
program
clock reference (PCR) values may also be modified accordingly. The PCR value
corresponds to a time reference value for synchronizing the time of the MPEG
decoder. Herein, the PCR value is inserted in a specific region of a TS packet
and then
transmitted.
[4121 In the example of the present invention, the packet jitter mitigator
1220 also
performs the operation of modifying the PCR value. The output of the packet
jitter
mitigator 1220 is inputted to the packet multiplexer 1240. As described above,
the
packet multiplexer 1240 multiplexes the main broadcast service data packet
outputted
from the packet jitter mitigator 1220 with the mobile broadcast service data
packet
outputted from the pre-processor 1230 into a burst structure in accordance
with a pre-
determined multiplexing rule. Then, the packet multiplexer 1240 outputs the
multiplexed data packets to the data randomizer 1251 of the post-processor
1250.
[4131 If the inputted data correspond to the main broadcast service data
packet, the data
randomizer 1251 performs the same randomizing process as that of the
conventional
randomizer. More specifically, the synchronization byte within the main
broadcast
service data packet is deleted. Then, the remaining 187 data bytes are
randomized by
using a pseudo random byte generated from the data randomizer 1251.
Thereafter, the
randomized data are outputted to the RS encoder/non-systematic RS encoder
1252.
[4141 On the other hand, if the inputted data correspond to the mobile
broadcast service
data packet, the data randomizer 1251 may randomize only a portion of the data
packet. For example, if it is assumed that a randomizing process has already
been
performed in advance on the mobile broadcast service data packet by the pre-
processor
1230, the data randomizer 1251 deletes the synchronization byte from the 4-
byte
MPEG header included in the mobile broadcast service data packet and, then,
performs
the randomizing process only on the remaining 3 data bytes of the MPEG header.
Thereafter, the randomized data bytes are outputted to the RS encoder/non-
systematic
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RS encoder 1252. More specifically, the randomizing process is not performed
on the
remaining portion of the mobile broadcast service data excluding the MPEG
header. In
other words, the remaining portion of the mobile broadcast service data packet
is
directly outputted to the RS encoder/non-systematic RS encoder 1252 without
being
randomized. Also, the data randomizer 1251 may or may not perform a
randomizing
process on the known data (or known data place holders) and the initialization
data
place holders included in the mobile broadcast service data packet.
[415] The RS encoder/non-systematic RS encoder 1252 performs an RS encoding
process
on the data being randomized by the data randomizer 1251 or on the data
bypassing the
data randomizer 1251, so as to add 20 bytes of RS parity data. Thereafter, the
processed data are outputted to the data interleaver 1253. Herein, if the
inputted data
correspond to the main broadcast service data packet, the RS encoder/non-
systematic
RS encoder 1252 performs the same systematic RS encoding process as that of
the
conventional broadcasting system, thereby adding the 20-byte RS parity data at
the end
of the 187-byte data. Alternatively, if the inputted data correspond to the
mobile
broadcast service data packet, the RS encoder/non-systematic RS encoder 1252
performs a non-systematic RS encoding process. At this point, the 20-byte RS
parity
data obtained from the non-systematic RS encoding process are inserted in a
pre-
decided parity byte place within the mobile broadcast service data packet.
[416] The data interleaver 1253 corresponds to a byte unit convolutional
interleaver. The
output of the data interleaver 1253 is inputted to the parity replacer 1254
and to the
non-systematic RS encoder 1255. Meanwhile, a process of initializing a memory
within the trellis encoding module 1256 is primarily required in order to
decide the
output data of the trellis encoding module 1256, which is located after the
parity
replacer 1254, as the known data pre-defined according to an agreement between
the
receiving system and the transmitting system. More specifically, the memory of
the
trellis encoding module 1256 should first be initialized before the received
known data
sequence is trellis-encoded. At this point, the beginning portion of the known
data
sequence that is received corresponds to the initialization data place holder
and not to
the actual known data. Herein, the initialization data place holder has been
included in
the data by the group formatter within the pre-processor 1230 in an earlier
process.
Therefore, the process of generating initialization data and replacing the
initialization
data place holder of the corresponding memory with the generated
initialization data
are required to be performed immediately before the inputted known data
sequence is
trellis-encoded.
[417] Additionally, a value of the trellis memory initialization data is
decided and
generated based upon a memory status of the trellis encoding module 1256.
Further,
due to the newly replaced initialization data, a process of newly calculating
the RS
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parity and replacing the RS parity, which is outputted from the data
interleaver 1253,
with the newly calculated RS parity is required. Therefore, the non-systematic
RS
encoder 1255 receives the mobile broadcast service data packet including the
ini-
tialization data place holders, which are to be replaced with the actual
initialization
data, from the data interleaver 1253 and also receives the initialization data
from the
trellis encoding module 1256.
[4181 Among the inputted mobile broadcast service data packet, the
initialization data
place holders are replaced with the initialization data, and the RS parity
data that are
added to the mobile broadcast service data packet are removed and processed
with
non-systematic RS encoding. Thereafter, the new RS parity obtained by
performing the
non-systematic RS encoding process is outputted to the parity replacer 255. Ac-
cordingly, the parity replacer 255 selects the output of the data interleaver
1253 as the
data within the mobile broadcast service data packet, and the parity replacer
255
selects the output of the non-systematic RS encoder 1255 as the RS parity. The
selected data are then outputted to the trellis encoding module 1256.
[4191 Meanwhile, if the main broadcast service data packet is inputted or if
the mobile
broadcast service data packet, which does not include any initialization data
place
holders that are to be replaced, is inputted, the parity replacer 1254 selects
the data and
RS parity that are outputted from the data interleaver 1253. Then, the parity
replacer
1254 directly outputs the selected data to the trellis encoding module 1256
without any
modification. The trellis encoding module 1256 converts the byte-unit data to
symbol
units and performs a 12-way interleaving process so as to trellis-encode the
received
data. Thereafter, the processed data are outputted to the synchronization
multiplexer
1260.
[4201 FIG. 40 illustrates a detailed diagram of one of 12 trellis encoders
included in the
trellis encoding module 1256. Herein, the trellis encoder includes first and
second mul-
tiplexers 1531 and 1541, first and second adders 1532 and 1542, and first to
third
memories 1533, 1542, and 1544. More specifically, the first to third memories
1533,
1542, and 1544 are initialized by a set of trellis initialization data
inserted in an ini-
tialization data place holder by the parity replacer 1254 and, then,
outputted. More
specifically, when the first two 2-bit symbols, which are converted from each
trellis
initialization data byte, are inputted, the input bits of the trellis encoder
will be
replaced by the memory values of the trellis encoder, as shown in FIG. 40.
[4211 Since 2 symbols (i.e., 4 bits) are required for trellis initialization,
the last 2 symbols
(i.e., 4 bits) from the trellis initialization bytes are not used for trellis
initialization and
are considered as a symbol from a known data byte and processed accordingly.
When
the trellis encoder is in the initialization mode, the input comes from an
internal trellis
status (or state) and not from the parity replacer 1254. When the trellis
encoder is in
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the normal mode, the input symbol provided from the parity replacer 1254 will
be
processed. The trellis encoder provides the converted (or modified) input data
for
trellis initialization to the non-systematic RS encoder 1255.
[422] More specifically, when a selection signal designates a normal mode, the
first
multiplexer 1531 selects an upper bit X2 of the input symbol. And, when a
selection
signal designates an initialization mode, the first multiplexer 1531 selects
the output of
the first memory 1533 and outputs the selected output data to the first adder
1532. The
first adder 1532 adds the output of the first multiplexer 1531 and the output
of the first
memory 1533, thereby outputting the added result to the first memory 1533 and,
at the
same time, as a most significant (or uppermost) bit Z2. The first memory 1533
delays
the output data of the first adder 1532 by 1 clock, thereby outputting the
delayed data
to the first multiplexer 1531 and the first adder 1532.
[423] Meanwhile, when a selection signal designates a normal mode, the second
multiplexer 1541 selects a lower bit X1 of the input symbol. And, when a
selection
signal designates an initialization mode, the second multiplexer 1541 selects
the output
of the second memory 1542, thereby outputting the selected result to the
second adder
1543 and, at the same time, as a lower bit Z1. The second adder 1543 adds the
output
of the second multiplexer 1541 and the output of the second memory 1542,
thereby
outputting the added result to the third memory 1544. The third memory 1544
delays
the output data of the second adder 1543 by 1 clock, thereby outputting the
delayed
data to the second memory 1542 and, at the same time, as a least significant
(or
lowermost) bit Z0. The second memory 1542 delays the output data of the third
memory 1544 by 1 clock, thereby outputting the delayed data to the second
adder 1543
and the second multiplexer 1541.
[424] The synchronization multiplexer 1260 inserts a field synchronization
signal and a
segment synchronization signal to the data outputted from the trellis encoding
module
1256 and, then, outputs the processed data to the pilot inserter 1271 of the
transmission
unit 1270. Herein, the data having a pilot inserted therein by the pilot
inserter 1271 are
modulated by the modulator 1272 in accordance with a pre-determined modulating
method (e.g., a VSB method). Thereafter, the modulated data are transmitted to
each
receiving system though the radio frequency (RF) up-converter 1273.
[425]
[426] Multiplexing Method of Packet Multiplexer 1240
[427] Data of the error correction encoded and 1/H-rate encoded primary RS
frame (i.e.,
when the RS frame mode value is equal to '00') or primary/secondary RS frame
(i.e.,
when the RS frame mode value is equal to '01'), are divided into a plurality
of data
groups by the group formatter 1303. Then, the divided data portions are
assigned to at
least one of regions A to D of each data group or to an MPH block among the
MPH
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blocks B 1 to B 10, thereby being deinterleaved. Then, the deinterleaved data
group
passes through the packet encoder 1304, thereby being multiplexed with the
main
broadcast service data by the packet multiplexer 1240 based upon a de-decided
mul-
tiplexing rule. The packet multiplexer 1240 multiplexes a plurality of
consecutive data
groups, so that the data groups are assigned to be spaced as far apart from
one another
as possible within the sub-frame. For example, when it is assumed that 3 data
groups
are assigned to a sub-frame, the data groups are assigned to a 1 slot (Slot
#0), a 5`h slot
(Slot #4), and a 9`h slot (Slot #8) in the sub-frame, respectively.
[4281 As described-above, in the assignment of the plurality of consecutive
data groups, a
plurality of parades are multiplexed and outputted so as to be spaced as far
apart from
one another as possible within a sub-MPH frame. For example, the method of
assigning data groups and the method of assigning parades may be identically
applied
to all sub-frames for each MPH frame or differently applied to each MPH frame.
[4291 FIG. 22 illustrates an example of a plurality of data groups included in
a single
parade, wherein the number of data groups included in a sub-frame is equal to
'3', and
wherein the data groups are assigned to an MPH frame by the packet multiplexer
1240.
Referring to FIG. 22, 3 data groups are sequentially assigned to a sub-frame
at a cycle
period of 4 slots. Accordingly, when this process is equally performed in the
5 sub-
frames included in the corresponding MPH frame, 15 data groups are assigned to
a
single MPH frame. Herein, the 15 data groups correspond to data groups
included in a
parade.
[4301 When data groups of a parade are assigned as shown in FIG. 22, the
packet
multiplexer 1240 may either assign main broadcast service data to each data
group, or
assign data groups corresponding to different parades between each data group.
More
specifically, the packet multiplexer 1240 may assign data groups corresponding
to
multiple parades to one MPH frame. Basically, the method of assigning data
groups
corresponding to multiple parades is very similar to the method of assigning
data
groups corresponding to a single parade. In other words, the packet
multiplexer 1240
may assign data groups included in other parades to an MPH frame according to
a
cycle period of 4 slots. At this point, data groups of a different parade may
be se-
quentially assigned to the respective slots in a circular method. Herein, the
data groups
are assigned to slots starting from the ones to which data groups of the
previous parade
have not yet been assigned. For example, when it is assumed that data groups
cor-
responding to a parade are assigned as shown in FIG. 22, data groups
corresponding to
the next parade may be assigned to a sub-frame starting either from the 12`h
slot of a
sub-frame.
[4311 FIG. 23 illustrates an example of assigning and transmitting 3 parades
(Parade #0,
Parade #1, and Parade #2) to an MPH frame. For example, when the 15t parade
(Parade
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#0) includes 3 data groups for each sub-frame, the packet multiplexer 1240 may
obtain
the positions of each data groups within the sub-frames by substituting values
'0' to '2'
for i in Equation 1. More specifically, the data groups of the 1St parade
(Parade #0) are
sequentially assigned to the 1s`, 5`h, and 9`h slots (Slot #0, Slot #4, and
Slot #8) within
the sub-frame. Also, when the 2d parade includes 2 data groups for each sub-
frame,
the packet multiplexer 1240 may obtain the positions of each data groups
within the
sub-frames by substituting values '3' and '4' for i in Equation 1. More
specifically, the
data groups of the 2d parade (Parade #1) are sequentially assigned to the 2d
and 12t
slots (Slot #3 and Slot #11) within the sub-frame. Finally, when the 3rd
parade includes
2 data groups for each sub-frame, the packet multiplexer 1240 may obtain the
positions
of each data groups within the sub-frames by substituting values '5' and '6'
for i in
Equation 1. More specifically, the data groups of the 3rd parade (Parade #2)
are se-
quentially assigned and outputted to the 7`h and 11t slots (Slot #6 and Slot
#10) within
the sub-frame.
[4321 As described above, the packet multiplexer 1240 may multiplex and output
data
groups of multiple parades to a single MPH frame, and, in each sub-frame, the
mul-
tiplexing process of the data groups may be performed serially with a group
space of 4
slots from left to right. Therefore, a number of groups of one parade per sub-
frame
(NOG) may correspond to any one integer from 'I' to W. Herein, since one MPH
frame
includes 5 sub-frames, the total number of data groups within a parade that
can be
allocated to an MPH frame may correspond to any one multiple of '5' ranging
from '5'
to '40'.
[4331
[4341 Processing Signaling Information
[4351 The present invention assigns signaling information areas for inserting
signaling in-
formation to some areas within each data group. FIG. 41 illustrates an example
of
assigning signaling information areas for inserting signaling information
starting from
the 1 segment of the 4`h MPH block (B4) to a portion of the 2nd segment. More
specifically, 276(=207+69) bytes of the 4d' MPH block (B4) in each data group
are
assigned as the signaling information area. In other words, the signaling
information
area consists of 207 bytes of the 1St segment and the first 69 bytes of the 2d
segment of
the 4d' MPH block (B4). For example, the 1St segment of the 4`h MPH block (B4)
corresponds to the 17`x' or 173rd segment of a VSB field. The signaling
information that
is to be inserted in the signaling information area is FEC-encoded by the
signaling
encoder 1304, thereby inputted to the group formatter 1303.
[4361 The group formatter 1303 inserts the signaling information, which is FEC-
encoded
and outputted by the signaling encoder 1304, in the signaling information area
within
the data group. Herein, the signaling information may be identified by two
different
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types of signaling channels: a transmission parameter channel (TPC) and a fast
in-
formation channel (FIC). Herein, the TPC information corresponds to signaling
in-
formation including transmission parameters, such as RS frame-associated in-
formation, SCCC-associated information, and MPH frame-associated information.
However, the signaling information presented herein is merely exemplary. And,
since
the adding or deleting of signaling information included in the TPC may be
easily
adjusted and modified by one skilled in the art, the present invention will,
therefore,
not be limited to the examples set forth herein. Furthermore, the FIC is
provided to
enable a fast service acquisition of data receivers, and the FIC includes
cross layer in-
formation between the physical layer and the upper layer(s).
[437] FIG. 42 illustrates a detailed block diagram of the signaling encoder
1304 according
to the present invention. Referring to FIG. 42, the signaling encoder 1304
includes a
TPC encoder 1561, an FIC encoder 1562, a block interleaver 1563, a multiplexer
1564,
a signaling randomizer 1565, and a PCCC encoder 1566. The TPC encoder 1561
receives 10-bytes of TPC data and performs (18,10)-RS encoding on the 10-bytes
of
TPC data, thereby adding 8 bytes of parity data to the 10 bytes of TPC data.
The 18
bytes of RS-encoded TPC data are outputted to the multiplexer 1564. The FIC
encoder
1562 receives 37-bytes of FIC data and performs (51,37)-RS encoding on the 37-
bytes
of FIC data, thereby adding 14 bytes of parity data to the 37 bytes of FIC
data.
Thereafter, the 51 bytes of RS-encoded FIC data are inputted to the block
interleaver
1563, thereby being interleaved in predetermined block units.
[438] Herein, the block interleaver 1563 corresponds to a variable length
block in-
terleaver. The block interleaver 1563 interleaves the FIC data within each sub-
frame in
TNoG(column)x51(row) block units and then outputs the interleaved data to the
multiplexer 1564. Herein, the TNoG corresponds to the total number of data
groups
being assigned to all sub-frames within an MPH frame. The block interleaver
1563 is
synchronized with the first set of FIC data in each sub-frame. The block
interleaver
1563 writes 51 bytes of incoming (or inputted) RS codewords in a row direction
(i.e.,
row-by-row) and left-to-right and up-to-down directions and reads 51 bytes of
RS
codewords in a column direction (i.e., column-by-column) and left-to-right and
up-
to-down directions, thereby outputting the RS codewords.
[439] The multiplexer 1564 multiplexes the RS-encoded TPC data from the TPC
encoder
1561 and the block-interleaved FIC data from the block interleaver 1563 along
a time
axis. Then, the multiplexer 1564 outputs 69 bytes of the multiplexed data to
the
signaling randomizer 1565. The signaling randomizer 1565 randomizes the
multiplexed data and outputs the randomized data to the PCCC encoder 1566. The
signaling randomizer 1565 may use the same generator polynomial of the
randomizer
used for mobile broadcast service data. Also, initialization occurs in each
data group.
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The PCCC encoder 1566 corresponds to an inner encoder performing PCCC-encoding
on the randomized data (i.e., signaling information data). The PCCC encoder
1566
may include 6 even component encoders and 6 odd component encoders.
[4401 FIG. 43 illustrates an example of a syntax structure of TPC data being
inputted to
the TPC encoder 1561. The TPC data are inserted in the signaling information
area of
each data group and then transmitted. The TPC data may include a sub-
frame_number
field, a slot-number field, a parade_id field, a starting-group-number (SGN)
field, a
number-of-groups (NoG) field, a parade_repetition_cycle (PRC) field, an
RS_frame_mode field, an RS_code_mode_primary field, an
RS_code_mode_secondary field, an SCCC_block_mode field, an
SCCC_outer_code_mode_A field, an SCCC_outer_code_mode_B field, an
SCCC_outer_code_mode_C field, an SCCC_outer_code_mode_D field, an
FIC_version field, a parade-continuity-counter field, and a TNoG field.
[4411 The Sub-Frame_number field corresponds to the current Sub-Frame number
within
the MPH frame, which is transmitted for MPH frame synchronization. The value
of the
Sub-Frame_number field may range from 0 to 4. The Slot_number field indicates
the
current slot number within the sub-frame, which is transmitted for MPH frame
syn-
chronization. Also, the value of the Sub-Frame_number field may range from 0
to 15.
The Parade-id field identifies the parade to which this group belongs. The
value of this
field may be any 7-bit value. Each parade in a MPH transmission shall have a
unique
Parade id field.
[4421 Communication of the Parade-id between the physical layer and the
management
layer may be performed by means of an Ensemble-id field formed by adding one
bit to
the left of the Parade-id field. If the Ensemble_id field is used for the
primary
Ensemble delivered through this parade, the added MSB shall be equal to U.
Otherwise, if the Ensemble-id field is used for the secondary ensemble, the
added
MSB shall be equal to '1'. Assignment of the Parade-id field values may occur
at a
convenient level of the system, usually in the management layer. The
starting-group-number (SGN) field shall be the first Slot-number for a parade
to
which this group belongs, as determined by Equation 1 (i.e., after the Slot
numbers for
all preceding parades have been calculated). The SGN and NoG shall be used
according to Equation 1 to obtain the slot numbers to be allocated to a parade
within
the sub-frame.
[4431 The number _of Groups (NoG) field shall be the number of groups in a sub-
frame
assigned to the parade to which this group belongs, minus 1, e.g., NoG = 0
implies that
one group is allocated (or assigned) to this parade in a sub-frame. The value
of NoG
may range from 0 to 7. This limits the amount of data that a parade may take
from the
main (legacy) service data, and consequently the maximum data that can be
carried by
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one parade. The slot numbers assigned to the corresponding Parade can be
calculated
from SGN and NoG, using Equation 1. By taking each parade in sequence, the
specific
slots for each parade will be determined, and consequently the SGN for each
succeeding parade. For example, if for a specific parade SGN = 3 and NoG = 3
(010b
for 3-bit field of NoG), substituting i = 3, 4, and 5 in Equation 1 provides
slot numbers
12, 2, and 6. The Parade_repetition_cycle (PRC) field corresponds to the cycle
time
over which the parade is transmitted, minus 1, specified in units of MPH
frames, as
described in Table 12.
[444]
[445] Table 12
PRC Description
000 This parade shall be transmitted once every MPH frame.
001 This parade shall be transmitted once every 2 MPH frames.
010 This parade shall be transmitted once every 3 MPH frames.
011 This parade shall be transmitted once every 4 MPH frames.
100 This parade shall be transmitted once every 5 MPH frames.
101 This parade shall be transmitted once every 6 MPH frames.
110 This parade shall be transmitted once every 7 MPH frames.
111 Reserved
[446]
[447] The RS_Frame_mode field shall be as defined in Table 1. The
RS_code_mode_primary field shall be the RS code mode for the primary RS frame.
Herein, the RS code mode is defined in Table 6. The RS_code_mode_secondary
field
shall be the RS code mode for the secondary RS frame. Herein, the RS code mode
is
defined in Table 6. The SCCC Block mode field shall be as defined in Table 7.
The
SCCC_outer_code_mode_A field corresponds to the SCCC outer code mode for
Region A. The SCCC outer code mode is defined in Table 8. The
SCCC_outer_code_mode_B field corresponds to the SCCC outer code mode for
Region B. The SCCC_outer_code_mode_C field corresponds be the SCCC outer code
mode for Region C. And, the SCCC_outer_code_mode_D field corresponds to the
SCCC outer code mode for Region D.
[448] The FIC_version field may be supplied by the management layer (which
also
supplies the FIC data). The Parade-continuity-counter field counter may
increase from
0 to 15 and then repeat its cycle. This counter shall increment by 1 every
(PRC+1)
MPH frames. For example, as shown in Table 12, PRC = 011 (decimal 3) implies
that
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Parade_continuity_counter increases every fourth MPH frame. The TNoG field may
be identical for all sub-frames in an MPH Frame. However, the information
included
in the TPC data presented herein is merely exemplary. And, since the adding or
deleting of information included in the TPC may be easily adjusted and
modified by
one skilled in the art, the present invention will, therefore, not be limited
to the
examples set forth herein.
[4491 Since the TPC parameters (excluding the Sub-Frame_number field and the
Slot-number field) for each parade do not change their values during an MPH
frame,
the same information is repeatedly transmitted through all MPH groups
belonging to
the corresponding parade during an MPH frame. This allows very robust and
reliable
reception of the TPC data. Because the Sub-Frame_number and the Slot - number
are
increasing counter values, they also are robust due to the transmission of
regularly
expected values.
[4501 Furthermore, the FIC information is provided to enable a fast service
acquisition of
data receivers, and the FIC information includes cross layer information
between the
physical layer and the upper layer(s).
[4511 FIG. 44 illustrates an example of a transmission scenario of the TPC
data and the
FIC data. The values of the Sub-Frame_number field, Slot-number field, Parade -
id
field, Parade_repetition_cycle field, and Parade-continuity-counter field may
corresponds to the current MPH frame throughout the 5 sub-frames within a
specific
MPH frame. Some of TPC parameters and FIC data are signaled in advance. The
SGN,
NoG and all FEC modes may have values corresponding to the current MPH frame
in
the first two sub-frames. The SGN, NoG and all FEC modes may have values cor-
responding to the frame in which the parade next appears throughout the 3rd,
4' and 5'
sub-frames of the current MPH frame. This enables the MPH receivers to receive
(or
acquire) the transmission parameters in advance very reliably.
[4521 For example, when Parade_repetition_cycle = '000', the values of the 3rd
4`,, and 5`,
sub-frames of the current MPH frame correspond to the next MPH frame. Also,
when
Parade_repetition_cycle = '011', the values of the 3rd, 4`,, and 5`, sub-
frames of the
current MPH frame correspond to the 4d' MPH frame and beyond. The FIC_version
field and the FIC_data field may have values that apply to the current MPH
Frame
during the 1 sub-frame and the 2nd sub-frame, and they shall have values cor-
responding to the MPH frame immediately following the current MPH frame during
the 3rd, 4ffi, and 5`f' sub-frames of the current MPH frame.
[4531 Meanwhile, the receiving system may turn the power on only during a slot
to which
the data group of the designated (or desired) parade is assigned, and the
receiving
system may turn the power off during the remaining slots, thereby reducing
power
consumption of the receiving system. Such characteristic is particularly
useful in
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portable or mobile receivers, which require low power consumption. For
example, it is
assumed that data groups of a 1s` parade with NOG=3, a 2nd parade with NOG=2,
and a
3rd parade with NOG=3 are assigned to one MPH frame, as shown in FIG. 45. It
is also
assumed that the user has selected a mobile broadcast service included in the
1s` parade
using the keypad provided on the remote controller or terminal. In this case,
the
receiving system turns the power on only during a slot that data groups of the
1s` parade
is assigned, as shown in FIG. 45, and turns the power off during the remaining
slots,
thereby reducing power consumption, as described above. At this point, the
power is
required to be turned on briefly earlier than the slot to which the actual
designated data
group is assigned (or allocated). This is to enable the tuner or demodulator
to converge
in advance.
[454]
[455] Assignment of Known Data (or Training Signal)
[456] In addition to the payload data, the MPH transmission system inserts
long and
regularly spaced training sequences into each group. The regularity is an
especially
useful feature since it provides the greatest possible benefit for a given
number of
training symbols in high-Doppler rate conditions. The length of the training
sequences is also chosen to allow fast acquisition of the channel during
bursted power-
saving operation of the demodulator. Each group contains 6 training sequences.
The
training sequences are specified before trellis-encoding. The training
sequences are
then trellis-encoded and these trellis-encoded sequences also are known
sequences.
This is because the trellis encoder memories are initialized to pre-determined
values at
the beginning of each sequence. The form of the 6 training sequences at the
byte level
(before trellis-encoding) is shown in FIG. 46. This is the arrangement of the
training
sequence at the group formatter 1303.
[457] The 1s` training sequence is located at the last 2 segments of the 3rd
MPH block (B3).
The 2d training sequence may be inserted at the 2d and 3rd segments of the 4`h
MPH
block (B4). The 2d training sequence is next to the signaling area, as shown
in FIG. 17.
Then, the 3rd training sequence, the 4`h training sequence, the 5`h training
sequence, and
the 6`h training sequence may be placed at the last 2 segments of the 4`h, 5`h
6`h, and 7`h
MPH blocks (B4, B5, B6, and B7), respectively. As shown in FIG. 46, the 1s`
training
sequence, the 3rd training sequence, the 4`h training sequence, the 5`h
training sequence,
and the 6`h training sequence are spaced 16 segments apart from one another.
Referring
to FIG. 46, the dotted area indicates trellis initialization data bytes, the
lined area
indicates training data bytes, and the white area includes other bytes such as
the FEC-
coded MPH service data bytes, FEC-coded signaling data, main broadcast service
data
bytes, RS parity data bytes (for backwards compatibility with legacy ATSC
receivers)
and/or dummy data bytes.
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[458] FIG. 47 illustrates the training sequences (at the symbol level) after
trellis-
encoding by the trellis encoder. Referring to FIG. 47, the dotted area
indicates data
segment sync symbols, the lined area indicates training data symbols, and the
white area
includes other symbols, such as FEC-coded mobile broadcast service data
symbols,
FEC-coded signaling data, main broadcast service data symbols, RS parity data
symbols
(for backwards compatibility with legacy ATSC receivers), dummy data symbols,
trellis
initialization data symbols, and/or the first part of the training sequence
data symbols.
Due to the intra-segment interleaving of the trellis encoder, various types of
data symbols
will be mixed in the white area.
[459] After the trellis-encoding process, the last 1416(=588+828) symbols of
the
1 st training sequence, the 3rd training sequence, the 4th training sequence,
the 5th training
sequence, and the 6th training sequence commonly share the same data pattern.
Including the data segment synchronization symbols in the middle of and after
each
sequence, the total length of each common training pattern is 1424 symbols.
The 2nd
training sequence has a first 528-symbol sequence and a second 528-symbol
sequence
that have the same data pattern. More specifically, the 528-symbol sequence is
repeated after the 4-symbol data segment synchronization signal. At the end of
each
training sequence, the memory contents of the twelve modified trellis encoders
shall be
set to zero(0).
[460] It will be apparent to those skilled in the art that various
modifications and
variations can be made to the embodiments described above. Thus, it is
intended that
the present invention covers the modifications and variations of this
invention provided
they come within the scope of the appended claims and their equivalents.
Mode for the Invention
[461] The embodiments of the invention are described in the best mode of the
invention.
Industrial Applicability
[462] The present invention can be used in broadcast and communication fields.
