Note: Descriptions are shown in the official language in which they were submitted.
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Description
A DIGITAL BROADCASTING TRANSMISSION SYSTEM, AND
A SIGNAL PROCESSING METHOD THEREOF
Technical Field
[1] Aspects of the invention relate to a method for turbo processing and
transmitting a
digital broadcasting transport stream, a digital broadcasting transmission
system, and a
method of processing signals thereof. More particularly, aspects of the
invention relate
to a method for turbo processing and transmitting a digital broadcasting
transport
stream to enhance reception performance of a terrestrial-wave digital
television (DTV)
system in the U.S. in accordance with the Advanced Television Systems
Committee
(ATSC) vestigial sideband (VSB) transmission system through information
exchange
and mapping with respect to a dual transport stream (TS) which includes normal
data
and turbo data, and a digital broadcasting transmission system.
Background Art
[2] The Advanced Television Systems Committee (ATSC) vestigial sideband
(VSB)
transmission system, which is used in a terrestrial-wave digital television
(DTV)
system in the U.S., is a single-carrier system that transmits one field
synchronization
(sync) segment for each unit of 312 data segments. Therefore, reception
performance
of the ATSC VSB system is inferior over weak channels, especially over a
Doppler-
fading channel.
[31 FIG. 1 is a block diagram of an ATSC VSB digital broadcasting
transceiver of the
related art. The digital broadcasting transceiver shown in FIG. 1 is
configured in
accordance with an enhanced VSB (E-VSB) system proposed by Phillips, and
produces and transmits a dual stream configured by adding enhanced or robust
data to
normal data of the standard ATSC VSB system.
[4] As shown in FIG. 1, a digital broadcasting transmitter includes a
randomizer 11, a
Reed-Solomon (RS) encoder 12 having a concatenated encoder form adding panty
bytes to a dual transport stream to enable en-ors generated by channel
impairments
during transmission to be corrected during reception, an interleaver 13
interleaving the
RS-encoded data according to a predetermined pattern, and a 2/3 rate trellis
encoder 14
performing trellis-encoding at a rate of 2/3 with respect to the interleaved
data and
mapping the interleaved data to 8-level symbols. With this structure, the
digital
broadcasting transmitter performs error-correction encoding with respect to
the dual
stream.
[51 The digital broadcasting transmitter further includes a multiplexer
15 inserting field
synchronization (sync) and segment sync in the en-or-correction encoded data
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according to a data format shown in FIG. 2, and a modulator 16 inserting a
pilot by
adding a predetermined direct current (DC) value to the data symbols and the
inserted
segment sync and field sync, amplitude-modulating the resulting signal onto an
in-
termediate frequency (IF) carrier, filtering the resulting IF signal to
produce a vestigial
sideband (VSB) signal, up-converting the VSB signal to a radio-frequency (RF)
signal
having a frequency of a desired channel, and transmitting the RF signal
through the
channel.
[6] Accordingly, in the digital broadcasting transmitter, the normal data
and the
enhanced or robust data are multiplexed according to the dual stream system
that
transmits the normal data and the enhanced or robust data on one channel and
are
inputted to the randomizer 11. The inputted data is randomized by the
randomizer 11,
and the randomized data is outer-encoded by the RS encoder 12 which is an
outer
encoder. The interleaver 13 distributes the encoded data according to the pre-
determined pattern. The interleaved data is inner-encoded by the trellis
encoder 14 in
12-symbol units. The inner-encoded data is mapped to 8-level symbols. The
field sync
and the segment sync are inserted in the mapped data. The pilot is inserted
and the
VSB modulation is performed. The VSB signal is up-converted to the RF signal,
and
the RF signal is transmitted through the channel.
[71 A digital broadcasting receiver shown in FIG. 1 includes a tuner (not
shown)
converting the RF signal received through the channel to a baseband signal, a
de-
modulator 21 performing synchronization detection and demodulation with
respect to
the baseband signal, an equalizer 22 compensating for channel distortion
generated by
multiple transmission paths with respect to the demodulated signal, a Viterbi
decoder
23 correcting errors of the equalized signal and decoding the error-corrected
signal to
symbol data, a deinterleaver 24 rearranging the symbol data according to the
pre-
determined pattern by which data was distributed by the interleaver 13 of the
digital
broadcasting transmitter, an RS decoder 25 correcting en-ors, and a
derandomizer 26
derandomizing the data corrected by the RS decoder 25 and outputting an MPEG-2
(Moving Picture Experts Group) transport stream. Therefore, the digital
broadcasting
receiver of FIG. 1 down-converts the RF signal to the baseband signal in a
reverse
order relative to the digital broadcasting transmitter, demodulates and
equalizes the
converted signal, and performs channel-decoding, thereby recovering the
original
signal.
[8] FIG. 2 shows a VSB data frame where the segment sync and the field
sync are
inserted according to an 8-VSB system which is used in the DTV system in the
U.S.
As shown in FIG. 2, one frame includes two fields. One field includes one
field sync
segment which is a first segment of the field, and 312 data segments. In the
VSB data
frame, one segment corresponding to one MPEG-2 packet comprises a 4-symbol
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segment sync and 828 data symbols. The segment sync and the field sync in FIG.
2 are
used for synchronization and equalization in the digital broadcasting
receiver. More
specifically, the segment sync and the field sync, which are known to the
digital
broadcasting transmitter and receiver, are used as reference signals when the
receiver
performs synchronization and equalization. The U.S. terrestrial-wave digital
broadcasting system of FIG. 1 is configured to produce and transmit the dual
stream by
adding the enhanced or robust data to the normal data of the ATSC VSB system
of the
related art. Therefore, the U.S. terrestrial-wave digital broadcasting system
transmits
the enhanced or robust data as well as the normal data.
Disclosure of Invention
Technical Problem
[91 Although the enhanced or robust data is transmitted in the dual
stream in addition to
the normal data, inferior reception performance due to multipath channel
distortion c
aused by transmission of the normal data stream is not remarkably improved. In
fact,
almost no improvement in the reception performance is obtained by the improved
normal data stream. Moreover, reception performance is not much improved with
respect to the enhanced or robust stream, either.
Technical Solution
[10] Accordingly, an aspect of the invention is to provide a method for
turbo processing
and transmitting a digital broadcasting transport stream to enhance reception
performance of a terrestrial-wave digital television (DTV) in the US in
accordance
with the advanced television system committee (ATSC) vestigial sideband (VSB)
through information exchange and mapping with respect to a dual transport
stream
(TS) which includes normal data and turbo data, a digital broadcasting
transmission
system, and a signal-processing method thereof.
[11] The above aspects and/or other features of the invention can
substantially be
achieved by providing a method of processing digital broadcasting signal,
comprising:
preparing a first area for parity insertion with respect to a dual transport
stream (TS)
which includes a normal stream and a turbo stream as multiplexed; interleaving
the
dual TS which includes the first area for parity insertion therein; detecting
the turbo
stream from the interleaved dual TS, exclusively encoding the detected turbo
stream,
and stuffing the encoded turbo stream in the dual TS for robust processing;
and dein-
terleaving the turbo-processed dual TS.
[12] According to an aspect of the invention, further comprising
multiplexing the normal
stream and the turbo stream to generate the dual TS.
[13] According to an aspect of the invention, before preparing the first
area for parity
insertion, randomizing the dual TS may be also provided.
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[14] According to an aspect of the invention, the generating the dual TS
comprises:
preparing a second area for parity insertion with respect to the turbo stream;
and
generating the dual TS by multiplexing the turbo stream having the second area
for
parity insertion therein with the normal stream.
[15] According to an aspect of the invention, the generating the dual TS
further
comprises: performing Reed-Solomon encoding with respect to an externally-
received
turbo stream; and interleaving the turbo stream.
[16] According to an aspect of the invention, the detecting the turbo
stream comprises:
detecting the turbo stream by demultiplexing the dual TS which is interleaved;
encoding the turbo stream by inserting a parity with respect to the detected
turbo
stream into the second area for parity insertion; interleaving the encoded
turbo stream;
and structuring the dual TS by multiplexing the interleaved turbo stream, and
the
normal stream multiplexed from the dual TS.
[17] According to an aspect of the invention, the detecting the turbo
stream comprises
further comprises: converting the basic unit of the interleaved dual TS from
byte to
symbol; and converting the basic unit of the structured dual TS structured
from symbol
to byte.
[18] According to an aspect of the invention, further comprising
transmitting the dein-
terleaved dual TS.
[19] According to an aspect of the invention, the transmitting the dual TS
comprises:
encoding, by inserting a parity with respect to the deinterleaved dual TS into
the first
area for parity insertion; interleaving the encoded dual TS; trellis-encoding
the in-
terleaved dual TS; multiplexing, by adding a synchronous signal to the trellis-
encoded
dual TS; and channel-modulating the multiplexed dual TS and transmitting the
resultant stream.
[20] According to an aspect of the invention, the dual TS comprises a field
containing a
plurality of consecutive packets, and the turbo stream is arranged in the
packets of the
field at predetermined packet intervals.
[21] According to an aspect of the invention, the dual TS comprises a field
containing a
plurality of consecutive packets, and an option field recording a
predetermined type of
packet information therein, is arranged in the packet which is located in a
pre-
determined position on the field without overlapping with the turbo stream.
[22] According to an aspect of the invention, the option field comprises at
least one of a
program clock reference (PCR), an original program clock reference (OPCR), a
splice
countdown which indicates a number of macro blocks, a transport private data
length
and an adaptation field extension length.
[23] The dual TS comprises a field containing a plurality of consecutive
packets, and the
turbo stream and the normal stream are arranged in the plurality of packets,
re-
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spectively.
[24] According to one aspect of the invention, a method of processing
digital
broadcasting signal may be provided, comprising: inserting an additional
reference
signal to a stuffing area of a dual transport stream (TS) which includes a
normal stream
and a turbo stream as multiplexed; preparing a first area for parity insertion
with
respect to the dual TS; interleaving the dual TS having the first insertion
for parity
insertion therein; detecting the turbo stream from the interleaved dual TS,
exclusively
encoding the detected turbo stream for robust processing, and stuffing the
encoded
turbo stream into the dual TS; and deinterleaving the dual TS which has the
encoded
turbo stream stuffed therein.
[25] According to one aspect of the invention, the method further comprises
transmitting
the deinterleaved dual TS.
[26] According to one aspect of the invention, the method further comprises
mul-
tiplexing the normal stream and the turbo stream to generate the dual TS, and
preparing the stuffing area in the dual TS, may be also provided.
[27] According to one aspect of the invention, before the inserting the
additional
reference signal, the method further comprises randomizing the dual TS which
has the
stuffing area therein.
[28] According to one aspect of the invention, the multiplexing comprises
preparing a
second area for parity insertion with respect to the turbo stream.
[29] According to one aspect of the invention, the multiplexing further
comprises: Reed-
Solomon encoding with respect to an externally-received turbo stream; and In-
terleaving the turbo stream.
[30] According to one aspect of the invention, the detecting the turbo
stream comprises:
detecting the turbo stream by demultiplexing the interleaved dual TS; encoding
the
turbo stream by inserting a parity with respect to the detected turbo stream
into the
second area for parity insertion; interleaving the encoded turbo stream; and
structuring
the dual TS by multiplexing the interleaved turbo stream and the demultiplexed
normal
stream.
[31] According to one aspect of the invention, the detecting the turbo
stream comprises
converting the basic unit of the interleaved dual TS from byte to symbol, and
detects
the turbo stream by demultiplexing.
[32] According to one aspect of the invention, the structuring the dual TS
structures
comprises multiplexing the interleaved turbo stream and the demultiplexed
normal
stream, and converting the basic unit of the dual TS from symbol to byte.
[33] According to one aspect of the invention, the method further
comprises: encoding,
by inserting a parity with respect to the deinterleaved dual TS into the first
area for
parity insertion; interleaving the encoded dual TS; trellis-encoding the
interleaved dual
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TS; multiplexing, by adding a synchronous signal to the trellis-encoded dual
TS; and
channel-modulating the multiplexed dual TS and transmitting the resultant
stream.
[34] According to one aspect of the invention, the trellis-encoding further
comprises ini-
tializing the trellis-encoder to a predetermined value.
[35] According to one aspect of the invention, the method further comprises
generating a
compatible parity, using the parity-added dual TS and the trellis-encoded dual
TS; and
recording the compatible parity in a location of the dual TS which corresponds
to the
parity added.
[36] According to one aspect of the invention, the dual TS is in the form
of a frame
comprising a plurality of consecutive packets, each packet comprising an
adaptation
field, and the stuffing area is at least a part of the adaptation field.
[37] According to one aspect of the invention, the dual TS comprises the
turbo stream
arranged in the packets of the frame at predetermined packet intervals.
[38] According to one aspect of the invention, the dual TS comprises an
option field
arranged in the packet located in a predetermined position of the field which
does not
overlap with the turbo stream, and the stuffing area is at least a part of the
adaptation
field excluding the option field.
[39] According to one aspect of the invention, the option field comprises
at least one of a
program clock reference (PCR), an original program clock reference (OPCR), a
splice
countdown which indicates a number of macro blocks, a transport private data
length
and an adaptation field extension length.
[40] According to one aspect of the invention, a digital broadcasting
transmission system
comprises a parity area generating unit preparing a first area for parity
insertion with
respect to a dual transport stream (TS) which includes a normal stream and a
turbo
stream as multiplexed; a first interleaver interleaving the dual TS which is
transmitted
from the parity area generating unit; a turbo processing unit detecting the
turbo stream
from the interleaved dual TS, exclusively encoding the detected turbo stream
for turbo-
processing, and stuffing the encoded turbo stream into the dual TS; a
deinterleaver
deinterleaving the dual TS which is processed by the turbo processing unit;
and a
transmitting unit transmitting the dual TS which is processed at the
deinterleaver.
[41] According to one aspect of the invention, the system further includes
a TS structure
unit generating the dual TS by multiplexing the normal stream and the turbo
stream;
and a randomizing unit randomizing the dual TS which is generated at the TS
structure
unit, and providing the generated dual TS to the parity area generating unit.
[42] According to one aspect of the invention, the TS structure unit
comprises: a
duplicator preparing a second area for parity insertion with respect to the
turbo stream;
and a service MUX multiplexing the turbo stream which is processed at the
duplicator,
and the normal stream, and outputting the resultant stream.
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[431 According to one aspect of the invention, the TS structure unit
further comprises: a
first Reed-Solomon encoder encoding an externally-received turbo stream, and
providing the resultant stream to the duplicator; and a pre-interleaver
interleaving the
turbo stream.
[441 According to one aspect of the invention, the turbo processing unit
comprises: a de-
MUX demultiplexing the dual TS which is interleaved in the first interleaver
and
detecting the turbo stream; a turbo encoder encoding the turbo stream by
inserting a
parity with respect to the turbo stream which is detected by the de-MUX, into
the
second area for parity insertion; a turbo interleaver interleaving the turbo
stream which
is processed at the turbo encoder; and a turbo data MUX structuring a dual
transport
stream (TS) by multiplexing the turbo stream which is processed at the turbo
in-
terleaver, and the normal stream which is demultiplexed at the de-MUX.
[451 According to one aspect of the invention, the turbo processing unit
further
comprises: a byte/symbol converting unit converting the basic unit from byte
to
symbol with respect to the dual TS which is processed at the first
interleaver, and
providing the converted stream to the de-MUX; and a symbol/byte converting
unit
converting the basic unit from symbol to byte with respect to the dual TS
which is
structured by the turbo data MUX.
[461 According to one aspect of the invention, the transmission unit
comprises: a second
Reed-Solomon encoder inserting a parity with respect to the dual TS, which is
processed at the deinterleaver, into the first area for parity insertion; a
second in-
terleaver interleaving the dual TS which is encoded at the second Reed-Solomon
(RS)
encoder; a trellis-encoder trellis-encoding the dual TS which is interleaved
by the
second interleaver; a MUX adding a synchronous signal to the trellis-encoded
dual TS;
and a modulating unit channel-modulating the multiplexed dual TS and
transmitting
the modulated signal.
[471 According to one aspect of the invention, the dual TS comprises a
field containing a
plurality of packets, and the turbo stream is arranged in the packets of the
field at pre-
determined packet intervals.
[481 According to one aspect of the invention, the dual TS comprises an
option field
recording a predetermined type of packet information therein, which is
arranged in the
packet at a predetermined position of the field which does not overlap with
the turbo
stream.
[491 According to one aspect of the invention, the dual TS comprises a
field containing a
plurality of consecutive packets, and the turbo stream and the normal stream
are
arranged in the plurality of packets, respectively.
[501 According to one aspect of the invention, a digital broadcasting
transmission system
comprises an additional reference signal inserting unit receiving a dual
transport
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stream (TS) including a normal stream and a turbo stream as multiplexed, and
inserting
an additional reference signal in a stuffing area provided in the dual TS; a
parity area
generating unit preparing a first area for parity insertion with respect to
the dual TS; a
first interleaver interleaving the dual TS which is transmitted from the
parity area
generating unit; a turbo processing unit detecting the turbo stream from the
interleaved
dual TS, exclusively encoding the detected turbo stream for robust processing,
and
stuffing the encoded turbo stream in the dual TS; a deinterleaver
deinterleaving the
dual TS which is processed at the turbo processing unit; and a transmitting
unit
transmitting the dual TS which is processed at the deinterleaver.
[51] According to one aspect of the invention, the transmission system
further includes a
transport stream (TS) structure unit generating the dual TS by multiplexing
the normal
stream and the turbo stream, and preparing the stuffmg area in the dual TS;
and a
randomizing unit randomizing the dual TS provided from the TS structure unit
and
providing the randomized stream to the additional reference signal inserting
unit, may
also be provided.
[52] According to one aspect of the invention, the TS structure unit
comprises: a
duplicator preparing a second area for parity insertion with respect to the
turbo stream;
and a service MUX multiplexing the turbo stream and the normal stream which
are
processed at the duplicator, preparing the stuffing area, and outputting the
resultant
stream.
[53] According to one aspect of the invention, the TS structure unit
further comprises: a
first Reed-Solomon encoder performing Reed-Solomon encoding with respect to an
externally-received turbo stream and providing the resultant stream to the
duplicator;
and a pre-interleaver interleaving the turbo stream.
[54] According to one aspect of the invention, the turbo processing unit
comprises: a de-
MUX demultiplexing the dual TS which is processed at the first interleaver and
detecting the turbo stream; a turbo encoder inserting a parity with respect to
the
detected turbo stream into the second area for parity insertion, and encoding
the turbo
stream; a turbo interleaver interleaving the turbo stream which is processed
at the turbo
encoder; and a turbo data MUX structuring the dual TS by multiplexing the
turbo
stream processed at the turbo interleaver, and the normal stream processed at
the de-
MUX.
[55] According to one aspect of the invention, the turbo processing unit
further
comprises: a byte/symbol converting unit converting the basic unit from byte
to
symbol with respect to the dual TS which is processed at the first
interleaver, and
providing the converted stream to the de-MUX; and a symbol/byte converting
unit
converting the basic unit from symbol to byte with respect to the dual TS,
which is
structured by the turbo data MUX.
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[56] According to one aspect of the invention, the transmitting unit
comprises; a second
Reed-Solomon encoder inserting a parity with respect to the dual TS, which is
processed at the deinterleaver, into the first area for parity insertion; a
second in-
terleaver interleaving the dual TS which is encoded by the second Reed-Solomon
encoder; a trellis-encoder trellis-encoding the dual TS which is interleaved
by the
second interleaver; a MUX adding a synchronous signal to the trellis-encoded
dual TS;
and a modulating unit channel-modulating the multiplexed dual TS.
[57] According to one aspect of the invention, the trellis-encoder
initializes to a preset
value before trellis-encoding the additional reference signal contained in the
dual TS
which is interleaved by the second interleaver.
[58] According to one aspect of the invention, the system further includes
a compatible
parity generating unit generating a compatible parity using the dual TS which
is
encoded by the trellis-encoder, and the dual TS added with the parity by the
second
Reed-Solomon encoder, may be also provided.
[59] According to one aspect of the invention, the trellis-encoder receives
the compatible
parity and records the received compatible parity in a position of the dual TS
which
corresponds to the parity added to the dual TS by the second Reed-Solomon
encoder.
[60] According to one aspect of the invention, the dual TS comprises a
frame containing
a plurality of consecutive packets, with each packet comprising an adaptation
field, and
the stuffing area is at least a part of the adaptation field.
[61] According to one aspect of the invention, the dual TS includes the
turbo stream
arranged in the packets of the frame at predetermined packet intervals.
[62] The dual TS comprises an option field arranged in the packet at a
location of the
adaptation field which does not overlap with the turbo stream, and the
stuffing area is
at least a part of the adaptation field excluding the option field.
[63] According to one aspect of the invention, the option field comprises
at least one of a
program clock reference (PCR), an original program clock reference (OPCR), a
splice
countdown which indicates a number of macro blocks, a transport private data
length
and an adaptation field extension length.
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[63a] According to one aspect of the invention, there is provided a digital
broadcast
receiver processes a transmission stream transmitted from a digital broadcast
transmitter, the
digital broadcast receiver, comprising: a decoder for performing decoding on a
supplementary
data included in the transmission stream, when the transmission stream
including the
supplementary data and a normal data is received, wherein the transmission
stream is
processed, at a digital broadcast transmitter, by performing error correction
encoding and
interleaving on the supplementary data and the processed supplementary data is
multiplexed
with the normal data, wherein the transmission stream further comprises a
field sync, a
segment sync and known data, and wherein the known data is used for
equalization at the
digital broadcast receiver, and the known data is a signal pattern which is
predetermined
between the digital broadcast transmitter of the transmission stream and the
digital broadcast
receiver.
[63b] According to one aspect of the present invention, there is provided a
method
for processing a transmission stream transmitted from a digital broadcast
transmitter, of a
digital broadcast receiver, the method comprising: performing decoding on a
supplementary
data included in the transmission stream, when the transmission stream
including the
supplementary data and a normal data is received, wherein the transmission
stream is
processed, at a digital broadcast transmitter, by performing error correction
encoding and
interleaving on the supplementary data and the processed supplementary data is
subsequently
multiplexed with the normal data, wherein the transmission stream further
comprises a field
sync, a segment sync and known data, and wherein the known data is used for
equalization at
the digital broadcast receiver, and the known data is a signal pattern which
is predetermined
between the digital broadcast transmitter of the transmission stream and the
digital broadcast
receiver.
[64] Additional aspects and/or advantages of the invention will be set
forth in part
in the description which follows and, in part, will be obvious from the
description, or may be
learned by practice of the invention.
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[65] According to one aspect of the invention, the field comprises
312 packets, and
when the 312 packets are divided into units of 52 packets each, the option
field is located in
the field as follows: Program clock reference (PCR): 52n+15, n=0; Original
program clock
reference (OPCR): 52n+15, n=1; Adaptation field extension length: 52n+15, n=2;
Transport
private data length: 52n+15, n=3,4,5; and Splice countdown: 52n+19,
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Advantageous Effects
[66] As can be appreciated from the above description of the method for
turbo-
processing and transmitting the TS for digital broadcasting, the digital
broadcasting
transmission/reception system, and the signal processing method thereof,
according to
certain embodiments of the invention, reception performance of a terrestrial-
wave
digital television (DTV) in the US in accordance with the advanced television
system
committee (ATSC) vestigial sideband (VSB) can be enhanced through information
exchange and mapping with respect to a dual transport stream (TS) which
includes
normal data and turbo data. As a result, the digital broadcasting transmission
system
provides not only the compatibility with existing normal data transmission
systems, but
also the improved receptivity under a variety of reception environments.
[67] While not required, it is understood that aspects of the invention can
be im-
plemented using software, hardware, and combinations thereof. While described
in
terms of a broadcast signal sent through air or cable, it is understood that,
the
transmission can be made through recording on a medium for delayed playback in
other aspects of the invention.
[68] While the invention has been shown and described with reference to
certain em-
bodiments thereof, it will be understood by those skilled in the art that
various changes
in form and details may be made therein without departing from the scope of
the claims.
Brief Description of the Drawings
[69] These and/or other aspects and advantages of the invention will become
apparent
and more readily appreciated from the following description of embodiments of
the
invention, taken in conjunction with the accompanying drawings, of which:
[70] FIG. 1 is a block diagram showing a digital broadcasting transceiver
of the related
art according to the Advanced Television Systems Committee (ATSC) vestigial
sideband (VSB) system;
[71] FIG. 2 shows an exemplary frame structure of a VSB data frame used in
the digital
broadcasting transceiver of the related art shown in FIG. 1;
[72] FIG. 3 is a block diagram showing a digital broadcasting transmission
system
according to an embodiment of the invention;
[73] FIG. 4 is a block diagram provided to explain in detail the structure
of the digital
broadcasting transmission system of FIG. 3;
[74] FIG. 5 is a block diagram showing a transport stream (TS) constructing
unit of the
digital broadcasting transmission system of FIG. 4;
[75] FIG. 6 is a block diagram showing in detail the structure of a
transmitting unit of
the digital broadcasting transmission system of FIG. 4;
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[76] FIG. 7 is a block diagram showing an example of a turbo processing
unit of the
digital broadcasting transmission system of FIG. 4;
[77] FIG. 8 is a block diagram showing the structure of a turbo encoder of
the turbo
processing unit of FIG. 7;
[78] FIGS. 9 through 15 show exemplary structures of a dual transport
stream packet of
the digital broadcasting transmission system of FIG. 4;
[79] FIG. 16 is a block diagram showing a digital broadcasting transmission
system that
transmits a supplementary reference sequence (SRS) according to an embodiment
of
the invention;
[80] FIGS. 17 through 23 show exemplary structures of a dual transport
stream packet
including the supplementary reference sequence (SRS) of the digital
broadcasting
transmission system of FIG. 16;
[81] FIG. 24 is a flowchart for explaining an example of a signal
processing method in
the digital broadcasting transmission system of FIG. 6; and
[82] FIG. 25 is a flowchart for explaining an example of a signal
processing method in
the turbo processing unit of FIG. 7.
Best Mode for Carrying Out the Invention
[83] Reference will now be made in detail to embodiments of the invention,
examples of
which are shown in the accompanying drawings, wherein like reference numerals
refer
to like elements throughout. The embodiments are described below in order to
explain
the invention by referring to the figures. The specific structures and
elements in the
following description are merely to assist in obtaining a comprehensive
understanding
of the invention. Thus, it is apparent that the invention can be implemented
without
using these specific structures and elements. Also, well-known functions,
structures,
and elements have not been described in detail in the following description to
avoid
obscuring the invention with unnecessary details.
[84] The following description presumes a familiarity with the Advanced
Television
Systems Committee (ATSC) Digital Television (DTV) System which incorporates
aspects of the MPEG-2 system, details of which are described in the
corresponding
standards. Examples of such standards which may be relevant are ATSC A/52B,
Digital Audio Compression Standard (AC-3, E-AC-3), Revision B, 14 June 2005;
ATSC A/53E, ATSC Digital Television Standard (A/53), Revision E, 27 December
2005; ATSC A/54A, Recommended Practice: Guide to the Use of the ATSC Digital
Television Standard, 4 December 2003; ISOJEC IS 13818-1:2000(E), Information
technology-enefic coding of moving pictures and associated audio information:
Systems (second edition) (MPEG-2); and ISOJEC IS 13818-2:2000(E), Information
technology-enefic coding of moving pictures and associated audio information:
Video
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(second edition) (MPEG-2).
However, it is understood that aspects of the invention can be im-
plemented according to other standards and systems without restriction.
Moreover, the
following description uses the terms "turbo" and "turbo data" which are
represented in
some of the drawings by the terms "robust" and "robust data".
[85] FIG. 3 is a block diagram showing a digital broadcasting transmission
system
according to an embodiment of the invention. Referring to FIG. 3, the digital
broadcasting transmission system includes a parity area generating unit 110, a
first in-
terleaver 120, a turbo processing unit 130, a deinterleaver 140, and a
transmitting unit
150. The parity area generating unit 110 provides an area for the insertion of
parity
bytes in a dual transport stream (TS), which includes a normal stream and a
turbo
stream. In other words, the parity is computed with respect to the dual TS,
and inserted
(that is, recorded in bits) into the parity area. The parity area provided by
the parity
area generating unit 110 will be called "a first parity insertion area" in the
following
description.
[86] The first interleaver 120 interleaves the dual TS which has an area
provided by the
parity area generating unit 110 for parity insertion. The turbo processing
unit 130
detects the turbo stream included in the interleaved dual TS, turbo-processes
the
detected turbo TS, and stuffs the dual TS. While not required in all aspects,
it is
understood that the turbo processing of the turbo processing unit 130 may
include
encoding processes such as convolution encoding with respect to the turbo TS
to make
the data turbo.
[87] The deinterleaver 140 deinterleaves the dual TS outputted from the
turbo processing
unit 130. The transmitting unit 200 transmits the dual TS after it has been
processed in
the deinterleaver 140. The structure of the transmitting unit 200 will be
described
below in detail.
[88] According to the embodiment shown in FIG. 3, a turbo stream, which has
been
treated with a separate turbo processing, is transmitted together with the
normal
stream. Therefore, reception performance under multipath conditions or in a
mobile
environment improves, and at the same time, compatibility with existing normal
stream transmission/reception system is provided. It is further understood
that the turbo
data can be various forms of data, such as audio, video, computer software,
game data,
music, shopping information, inter/let data, text, voice data, and other types
of data
transmitted in addition to the normal data. Additionally, the normal data can
include
other data in addition to or instead of the audio-video data used in digital
broadcasting
according to aspects of the invention.
[89] The digital broadcasting transmission system of FIG. 3 will be
explained in greater
detail below with reference to the block diagram of FIG. 4. Referring to FIG.
4, the
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WO 2007/043802 PCT/KR2006/004085
digital broadcasting transmission system further includes a transport stream
(TS)
generating unit 300 and a randomizer unit 150. The TS generating unit 300
generates a
dual TS by receiving a normal stream and a turbo stream, processing the turbo
stream,
and multiplexing the normal stream and the processed turbo stream. While not
required
in all aspects, the normal stream and the turbo stream may be received from an
external
module such as a broadcasting camera, or internal modules such as compression
module such as MPEG-2 module, a video encoder, and an audio encoder.
[90] The randomizer unit 150 randomizes the dual TS generated by the TS
generating
unit 300 and provides it to the parity area generating unit 110. Accordingly,
the parity
area generating unit 110 provides a parity area for the dual TS. Since the
elements in
FIG. 4 other than the TS generating unit 300 and the randomizer unit 150 are
same in
function as those of the above-described embodiment of FIG. 3, additional
description
will be omitted for the sake of brevity.
[91] An exemplary structure of the TS generating unit 300 will be described
below with
reference to FIG. 5. The TS generating unit 300 includes a first Reed-Solomon
encoder
310, a pre-interleaver 320, a duplicator 330, and a service MUX (multiplexer)
340.
Although the example shown in FIG. 5 uses the first Reed-Solomon encoder 310
and
the pre-interleaver 320, these can be omitted or replaced with other elements
(not
shown). It is preferable, but not required, that the first Reed-Solomon
encoder 310,
when used, be used together with the pre-interleaver 320. The position of the
pre-
interleaver 320 is interchangeable with that of the duplicator 330.
[92] The first Reed-Solomon encoder 310 performs encoding by adding parity
bytes to
the received turbo stream. The pre-interleaver 320 interleaves the turbo
stream having
the added parity bytes. The duplicator 330 provides a parity area with respect
to the in-
terleaved turbo stream. The parity area provided by the duplicator 330 will be
called a
"second parity area" in the following description.
[93] In order to provide the second parity area, the byte, which is the
basic unit of the
turbo stream, is divided into two or four bytes. A part of bits of one byte,
and null data
such as 0, are then stuffed in each of the bytes. The area stuffed with the
null data
becomes the parity area.
[94] The service MUX 340 multiplexes the normal stream which is separately
received
with the turbo stream processed in the duplicator 330. As the dual TS is
generated, the
service MUX 340 provides the dual TS to the randomizer unit 150.
[95] An exemplary structure of the transmitting unit 200 of the digital
broadcasting
transmission system of FIG. 4 will be explained below with reference to the
block
diagram of FIG. 6. As shown in FIG. 6, the transmitting unit 200 includes a
second
Reed-Solomon encoder 210, a second interleaver 220, a trellis encoder 230, a
MUX
240, and a modulator 250. The second Reed-Solomon encoder 210 encodes the dual
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TS received from the deinterleaver 140 by adding the parity bytes to the dual
TS. More
specifically, the second Reed-Solomon encoder 210 inserts parity bytes
computed with
respect to the dual TS in the first parity area provided by the parity area
generating unit
110.
[96] The second interleaver 220 interleaves the dual TS having the added
parity bytes
added by the second Reed-Solomon encoder 210. The trellis encoder 230 encodes
the
dual TS after the dual TS is interleaved by the second interleaver 220. The
MUX 240
multiplexes the dual TS after the trellis encoding by adding segment sync and
field
sync to the dual TS. The modulator 250 modulates channel of the dual TS after
the
multiplexing, and up-converts into a signal of RF channel band. Accordingly,
the dual
TS is transmitted to a variety of reception systems via the channel. Although
not
shown in FIG. 6 and while not required in all aspects, the transmission unit
200 may
additionally include general components for the signal transmission, such as a
power
amplifier (not shown) which amplifies the power of the modulated signal of the
modulator 250, and an antenna (not shown), and may further include elements
used to
broadcast within cable, internet, and/or satellite systems and media through
which
digital broadcasts can be implemented.
[97] An exemplary structure of the turbo processing unit 130 of the digital
broadcasting
transmission system of FIG. 4 will be explained below with reference to the
block
diagram of FIG. 7. With reference to FIG. 7, the turbo processing unit 130
includes a
byte/symbol converting unit 131, a de-MUX 132, a turbo encoder 133, a turbo in-
terleaver 134, a turbo data MUX 135, and a symbol/byte converting unit 136.
The
byte/symbol converting unit 131, the de-MUX 132, the turbo data MUX 135, and
the
symbol/byte converting unit 136 may be omitted, or replaced with other
components in
other aspects of the invention.
[98] The byte/symbol converting unit 131 converts the basic unit of the
interleaved dual
TS of the first interleaver 120 from bytes to symbols. Conversion of the basic
unit from
byte to symbol will be easily understood with reference to the table D5.2 of
U.S.
ATSC DTV standard (A/53).
[99] The de-MUX 132 demultiplexes the dual TS of symbol unit to recover the
turbo
stream. The turbo encoder 133 computes parity bytes with respect to the
detected turbo
stream, and encodes the turbo stream by stuffing the second parity area with
the
computed parity bytes. In this particular example, the turbo encoder 133
performs
encoding in the unit of each byte of the turbo stream. However, it is
understood that
other units can be used.
[100] The turbo interleaver 134 interleaves the turbo stream which is
convolution-
encoded. In this example, the turbo interleaver 134 interleaves in the unit of
bit. The
15
WO 2007/043802 PCTXR2006/004085
turbo data MUX 135 generates a dual TS by multiplexing the interleaved turbo
stream
and the normal stream. More specifically, the turbo data MUX 135 constructs a
dual
TS by stuffing the turbo stream to the place before it is detected by the de-
MUX 132.
The symbol/byte converting unit 136 converts the basic unit of the dual TS
from
symbols to bytes. This conversion will be easily understood with reference to
the table
D5.2 of the U.S. ATSC DTV standard (A/53), the disclosure of which is
incorporated
by reference.
[1011 An example of the byte-to-symbol table of table D5.2 is as follows:
[1021
.yril 1:'.I Seri LIM 0 Segment 1 Se c 111@flt 2 Si rne.i It 2
S=Pg rrm-11 4
Troll's Byte. Eft; Tr4.111G Er5.14. EIV, 7rolll.s Bile BIti: Tre.Ills By1e
Blt9 "Trellis. Eyte B11-3
1 1 1 1 0 7.8 4 21:18 .5.4 8 412 :3,2 0
61e. 1,0 -} =.c'e. 7,'.5
1 1 1 7.3 5 200 5,4 c. 4 13 :?.,2 1
617 Li:. 5 .=I'g 7,6
2 2 7. E; 6 21':' 5.4 10 -114 :?.,2 2
618 LC. b 6311. 7,6
=
3 3 3 7,3 7 211 Z.4 11 415 :?.,2 f.k
.. 1 CI 1 ,.: ...
4 4 4 7,3 6 212 Z.4 0 41E :?.,2 4 ;20 1,0 .. .. .
.`:. 7.3 :;. 21: Z,4 1 417 :3,2 5 621 1,0 ...
6 6 6 7,3 10 214 Z.4 2 418 :?.,2 6
6'7'2 1,0 ... . ..
7 7 7 7,1; 11 215 -`...-1 2 411 :.1,;1' 7
;T:?. 1,') ... . ..
8 a 8 7.3 0 2.14 5.4 4 406. :3,2 8 612
1,0 ... .. ...
9 ..? 6, 7.3 1 205 5.4 5 409 :3,2 g 613 1,0 ... ..
...
ID 1 C. E. 7.3 2 206 5.4 6 410 :3,2 10
,;14 1 ..:, ... .. ...
11 11 11 7.3 3 207 .5.4 7 411 :3,2 1 1
615 1..:. ... .. ...
12 1.) .-1- 4 2028 :32 8 412 1,G, 0 ,524
7,,f= ...
12.. 1 1 5.4 5 20g --3.2 g 412. 1,C. 1
... ...
7 7 5.4 11 215 :3.2 3 419 1,0 7 '631 7.6 ... ... ...
8 5.4 0 2.:4 :3.2 4 4:.6. 1,0
8.'632 7,6 ... ... ...
21 g 5.4 1 205 :3.2 5 4..:19 1,C. g 633 7,6 ... ...
...
22 10 10 5,4 1.. 206 :3.2 6 410 1,0 10 .;84
7.6 ... ... ...
11 11 .4 3 21117 --?..2 7 411 1,0 11
1.8 7.Ã ... ... ...
24 (.1 u -2.2 4 206 1.0 6 420 7,6. 0 624 5,4 ... ...
...
1 2.2 5 '''.'...f.1 LC. 41 7 ,., 1
;I.!: !..4 ... ... ...
31 7 7 22 11 215 1.0 3 427 7,6. ...... ... ...
... ...
''Z' 6 2 =,i' ':.1 2(.4 1,r., 4 42.::.
7,6. ... ... ...
... ... ...
32. ..]. g 2 =7= 1 205 1.0 7. 429 7,6 ...
. .. ..
34 111 El 2.2 2 21-Jti 1.11 4.?0 7,=.. ...
. .. .. . ..
3 5 11 11 2.2 3 207 1.0 7 431 7,6 ... ..
... ... .. ...
36. 0 0 1..) 4 216 7.6 B 420 5,4 ... . .. ..
. ..
37 1 1 1.L 5 217 7.6 g 421 5,4 ... ..
... ... .. ...
. ... ...
41 11 11 i=':, 3 -7 7,,f.. ...
... ...
... ... ... ... ... ...
4.-?. 12 7.i. 4 21E. 5.4 .. ... . ... ..
... ...
4g 1 i'. 7.1; 5 217 '...4. .. ... . ...
.. ... ... .. ..
... . . . .. ... .. .
.
11 23 1.C.. .. .. . . .. ... . . ..
... .. . .
[1031
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WO 2007/043802 PCT/KR2006/004085
.) L-4 . .
1
. .
- - - -
11 1 1 ,1) . . .
71,8 1) 1:22 7,5 ..
. .
1 i Tb .
11 2=',3 1,0 $ 41D 7,6 7 6)3 ;,4 11 X27 32 .
2.4 7, 4 ==12 .2..2 C.
.q17 1 7,5 5 4f_19 ',4 =,13 2..2 1 ki7 _
N-27 11 215 7,6 3 419 f,4 7 623 .3,2
11R:27 1.. .
[1041 An exemplary structure of the turbo encoder 133 of the turbo
processing unit 130 of
FIG. 7 will now be explained with reference to the block diagram of FIG. 8.
According
to FIG. 8, the turbo encoder 133 includes a shift register having three
elements D and
two adders. Accordingly, the turbo encoder 133 convolution-encodes the data to
recursive systematic convolutional (RSC) code, to insert parities in the
second parity
area.
[1051 FIGS. 9 through 15 show exemplary structures of the dual TS of the
digital
broadcasting transmission system of FIG. 4. FIG. 9 shows an example of a turbo
stream packet received by the TS structure unit 300. The turbo stream packet
may
comprise 188 bytes, for example. In this case, more particularly, the turbo
stream
packet comprises 1 byte of sync which is a header, 3 bytes of packet identity
(MD),
and 184 bytes of turbo data.
[1061 FIG. 10 shows an example of a normal stream packet received by the TS
structure
unit 300. The normal stream packet may comprise 188 bytes, more particularly,
1 byte
of sync that is a header, 2 bytes of an adaptation field (AF) header, N bytes
of null
data, and 182-N bytes of normal data. The AF header is an area where
information
about an adaptation field is recorded, so it contains information such as a
location, a
size, and so on of the adaptation field.
[1071 FIG. 11 shows an example of a dual TS (or, a stream packet) generated
by the TS
generating unit 300. In FIG. 11, a part of the turbo stream packet of FIG. 9
is inserted
in the null data of the normal stream packet of FIG. 10. In this embodiment,
the dual
TS comprises 188 bytes, more particularly, 1 byte of sync which is a header, 3
bytes of
PID, 2 bytes of an AF header, N bytes of null data, and 182-N bytes of normal
data
which is a payload. The inserted turbo data shown in FIG. 11 may be a part of
the
turbo stream packet of FIG. 9. For example, the inserted turbo data of FIG. 11
may be
at least one of the sync, the MD, and the turbo data of FIG. 9.
[1081 FIG. 12 shows a dual TS generated by the TS generating unit 300
according to
another embodiment of the invention. According to the embodiment shown in FIG.
12,
the dual TS includes a plurality of consecutive packets. Turbo data is
arranged with
respect to a predetermined number of packets. That is, FIG. 12 shows that 78-
packet
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WO 2007/043802 PCT/KR2006/004085
turbo streams are inserted in 312-segment packets of one field of the dual TS.
The dual
TS comprises 1 packet (188 bytes) of the turbo stream and 3 consecutive
packets (188
bytes) of the normal streams which are repeatedly arranged at the rate of 1:3.
[109] In case that 70-packet turbo streams are inserted in 312-segment
packets of the dual
TS, the dual TS is structured in a manner that 4 packets comprising 1 packet
(188
bytes) of the turbo streams and 3 consecutive packets (188 bytes) of the
normal
streams are repeatedly arranged 70 times, and the rest 32 packets comprise the
normal
stream packets.
[110] FIG. 13 shows a dual TS packet structured by the TS structure unit
300, according
to yet another embodiment of the invention. 88 packets of the turbo streams
are
inserted in 312 segments of the packets of one field of the dual TS. The dual
TS is
structured in a manner that 4 packets comprising 2 packets (188 bytes) of the
turbo
streams and 2 packets (188 bytes) of the normal streams are repeatedly
arranged 10
times, and 4 packets comprising 1 packet (188 bytes) of the turbo stream and 3
consecutive packets (188 bytes) of the normal streams are repeatedly arranged
at the
rate of 1:3 as shown in FIG. 12.
[111] FIG. 14 shows a dual TS structured by the TS structure unit 300,
according to still
another embodiment of the invention, which is a combined form of the dual TS
shown
in FIGS. 11 and 12. The dual TS is structured in a manner that 4 packets are
repeatedly
arranged, the 4 packets comprising 1 packet (188 bytes) of the turbo stream, 1
packet
of the normal stream wherein SRS data and the turbo data are inserted in a
part of the
AF of the normal stream packet, and 2 packets (188 bytes) of the normal stream
packets.
[112] FIG. 15 shows the dual TS which is structured in the form of 312-
segment packets.
As shown in FIG. 15, packet information, along with the turbo data and the
normal
data, is included in the dual TS. The packet information may be recorded in
the option
field. In this case, locations of option field can be designated and fixed so
as not to
overlap with the turbo data. In FIG. 15, "m" denotes a possible length (byte)
of the
turbo data.
[113] According to FIG. 15, the option fields recording the number of macro
blocks
(splice countdown) are arranged in the segments 11, 63, 115, 167, 219, 271,
while the
option fields recoding program clock reference (PCR) are arranged in the
segments 15,
67, 119.
[114] When dividing the 312 segments into 52-segment units, the locations
of the option
fields can be expressed as follows:
[115] Program clock reference (PCR) (using 6 bytes): 52n+15, n=0;
[116] Original program clock reference (OPCR) (using 6 bytes): 52n+15, n=1;
[117] Adaptation field extension length (using 2 bytes): 52n+15, n=2;
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WO 2007/043802 PCT/KR2006/004085
[118] Transport private data length (using 5 bytes): 52n+15, n=3, 4, 5; and
[119] a number of macro blocks (splice countdown) (using 1 byte): 52n+15,
n=0, 1, 2, 3,
4, 5
[120] The "Transport private data length" among these, for example, exists
in the
segments 171, 223, 275. The dual TS in which the turbo data is inserted in the
null data
except the option fields can be structured in various ways besides the above-
introduced
ways. Additionally, the structural rate of the turbo data can be adjusted
according to
the structure of the dual TS packet.
[121] FIG. 16 is a block diagram showing a digital broadcasting
transmission system that
transmits a supplementary reference sequence (SRS). While described in the
context of
SRS, it is understood that other training sequences and/or sets of known data
can be
implemented in other aspects of the invention. Referring to FIG. 16, the
digital
broadcasting transmission system includes a TS structure unit 801 including a
stuffing
region to insert SRS data in respective packets of the dual TS, a randomizer
803
randomizing the dual TS packet (hereinafter, referred to as merely "packet"),
a sup-
plementary reference sequence inserting unit 805 inserting the SRS data in the
stuffing
region of the randomized packet, a parity area generating unit 807 generating
a first
area for inserting a parity for error correction, a first interleaver 809
primarily in-
terleaving the packet where the first area is generated, a turbo processing
unit 811
convolution-encoding and interleaving the turbo stream included in the
primarily in-
terleaved packet, a deinterleaver 813 deinterleaving the packet processed by
the turbo
processing unit 811, a Reed-Solomon (RS) encoder 815 inserting the parity in
the first
area of the deinterleaved packet, a second interleaver 817 secondarily
interleaving the
packet where the parity is inserted, a trellis encoder 819 trellis encoding
the interleaved
packet, a MUX 823 multiplexing the trellis-encoded packet by adding a sync,
and a
modulator 825 channel-modulating and transmitting the multiplexed packet. Ad-
ditionally, a backwards compatibility parity generator 821 generating a
compatible
parity may be further included.
[122] Known SRS data for synchronization and/or channel equalization may be
inserted
in the dual TS packet received by the digital broadcasting transmission, which
will be
described in detail with reference to FIG. 9. The TS structure unit 801
receives the
normal stream and the turbo stream and structures the dual TS packet.
According to an
embodiment of the invention, the dual TS packet may include a stuffing region
for
inserting therein the known SRS data for synchronization and/or channel
equalization.
The TS structure unit 801 may be constructed in the same way as explained
above with
reference to FIG. 5, and therefore, description thereof will be omitted for
the sake of
brevity. If the TS structure unit 801 includes the first Reed-Solomon encoder
310 as in
the above embodiment shown in FIG. 5, the Reed-Solomon encoder 815 of FIG. 16
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WO 2007/043802 PCT/KR2006/004085
will be called as a second Reed-Solomon encoder for the convenience in
explanation.
[123] The stuffing region for inserting therein the known SRS data for
synchronization
and/or channel equalization will now be described. The stuffing region may be
a part
of the packet including a header and a payload. More particularly, the packet
further
includes an adaptation field (AF). The stuffing region as part of the AF is
positioned
not to be overlapped with the option field included in the AF. The option
field
comprises a program clock reference (PCR) used for synchronization of a
demodulator
of a receiver, an original PCR (OPCR) used for recording, reservation, and re-
production of a program in the receiver, four circuit blocks, the number of
macro
blocks (splice countdown) denoting the number of consecutive macro blocks
comprising one Cr block and one Cb block, transport private data length
denoting
length of text data for teletext broadcasting, and AF extension length.
[124] According to an embodiment of the invention, the AF of the packet may
further
include a stuffing region for inserting therein data for initializing the
trellis encoder
809 that will be described hereinafter. The randomizer 803 randomizes the
packet
including the stuffing region.
[125] The SRS inserting unit 805 inserts the SRS data in the stuffing
region of the
randomized packet. Here, the SRS data is a reference signal, that is, specific
sequence
data having a pattern predetermined by the transmitter and the receiver. Since
the SRS
data is different from general payload data transceiving the pattern of the
reference
signal, the SRS data can be detected easily from general packets to be
transmitted and
thereby used for synchronization of the receiver and/or channel equalization.
The
insertion of the SRS data in the stuffing region can be controlled by a
predetermined
controlling signal.
[126] The parity area generating unit 807 generates a first area for
inserting the parity for
en-or correction in the packet where the SRS data is inserted. As shown, the
first area is
for inserting therein the parity added by the RS encoder 815. The first
interleaver 809
primarily interleaves the packet where the parity area is generated. The turbo
processing unit 811 convolution-encodes the turbo stream included in the
primarily in-
terleaved packet and interleaves the convolution-encoded turbo stream. The
turbo
processing unit 811 is configured as shown in FIG. 7 and operates in the same
manner
as described with reference to FIG. 7.
[127] The deinterleaver 813 deinterleaves the packet output from the turbo
processing
unit 811. The RS encoder 815 adds the parity to the deinterleaved dual TS.
According
to an embodiment of the invention, the RS encoder 815, being structured in the
form of
concatenated code, inserts the parity to correct en-ors generated by the
channel at the
first area of the packet where the SRS data is inserted. The second
interleaver 817
secondarily interleaves the packet where the parity is inserted. The trellis
encoder 819
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WO 2007/043802 PCT/KR2006/004085
trellis encodes the secondarily interleaved packet.
[128] According to an embodiment of the invention, the trellis encoder 819
can be
initialized to a predetermined value right before the SRS data included in the
in-
terleaved packet is trellis-encoded. The initialization is required due to the
SRS data.
More specifically, the trellis encoder 819 may generate different encoded
results for
the same data depending on the previously encoded data. Therefore, the result
of trellis
encoding of the SRS data may vary according to data previous to the SRS data
and in
this case, the receiver cannot discriminate the SRS data. To solve such a
problem, the
trellis encoder 819 is initialized to the predetermined value right before
trellis encoding
of the SRS data. In other words, the predetermined value is trellis encoded
right before
the SRS data is trellis-encoded.
[129] The trellis encoder 819 according to an embodiment of the invention
may include i)
a general mode that trellis encodes the packet interleaved by the interleaver,
ii) an ini-
tialization mode that initializes the trellis encoder 819, and iii) a panty
replacement
mode that trellis-encodes the compatible panty substituted for the whole or a
part of
the parity applied by the RS encoder 815. For this purpose, the trellis
encoder 819 may
receive a control signal from a control signal generation unit (not shown),
the control
signal operated in the general mode, the initialization mode, or the parity
replacement
mode.
[130] When the trellis encoder 819 receives a control signal commanding the
initialization
mode while operating in the general mode, the trellis encoder 819 is operated
in the
initialization mode. If it receives a control signal commanding the parity
replacement
mode while it is operating in the general mode, the trellis encoder 819 is
operated in
the parity replacement mode. The control signal may be supplied from the
control
signal generation unit (not shown) which is aware of location of the inserted
SRS data,
location of the inserted value for initializing the trellis encoder 819, and
location for
replacing the compatible parity.
[131] The backwards compatibility panty generating unit 821 receives the
packet where
the parity is added by the RS encoder 815 and the packet encoded by the
trellis encoder
819, and generates the compatible panty based on the received packets. More
specifically, the backwards compatibility parity generating unit 821 includes
a symbol
decoder (not shown) receiving the packet encoded by the trellis encoder 819
and
converting a symbol-mapped packet to a byte form, a deinterleaver (not shown)
dein-
terleaving the decoded packet, and a memory (not shown) replacing at least a
part of
the received packet with the deinterleaved packet and storing the
deinterleaved packet.
Preferably, the memory (not shown) may replace and store only the different
part
between the received packet and the deinterleaved packet. For this, the
backwards
compatibility panty generating unit 821 may receive a predetermined control
signal
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from the control signal generation unit (not shown), for example. The memory
(not
shown) may include an RS encoder (not shown) adding the compatible parity to
the
packet stored in the memory, an interleaver (not shown) interleaving the
packet where
the compatible parity is added, and a symbol encoder (not shown) symbol-
mapping the
packet in the byte form in order to transmit the interleaved packet to the
trellis encoder
819.
[132] The MUX 823 multiplexes the trellis-encoded packet by adding the
segment sync
and the field sync to the trellis-encoded packet. The modulator 825 performs
channel-
modulation with respect to the packet where the segment sync and the field
sync are
added, up-converts the modulated packet to a signal of an RF channel band, and
transmits the converted signals.
[133] FIGS. 17 through 23 show the structure of a TS packet including the
SRS,
according to an embodiment of the invention. FIG. 17 shows a turbo stream
packet
received by the TS structure unit 801. The turbo stream packet (188 bytes)
comprises 1
byte of sync which is a header, 3 bytes of PID, and 184 bytes of turbo data.
FIG. 18
shows a normal stream packet including a stuffing region for inserting the
known SRS
signal for synchronization in the TS structure unit. The normal stream packet
(188
bytes) comprises 1 byte of sync which is a header, 3 bytes of PID, 2 bytes of
AF
header, S-bytes of stuffing region, N-bytes of null data, and 182-N-S bytes of
normal
data which is a payload. FIG. 19 shows a dual TS packet including the stuffing
region
for inserting the known SRS signal for synchronization in the TS structure
unit,
according to an embodiment of the invention. More specifically, in FIG. 19,
part of the
turbo stream packet of FIG. 17 is inserted in the null data of the normal
stream packet
of FIG. 11B, and the SRS data is inserted in the stuffing region. In this
embodiment,
the dual TS comprises 188 bytes, more particularly, 1 byte of sync which is a
header, 3
bytes of PID, 2 bytes of AF header, S-bytes of SRS data, N-bytes of null data,
and a
182-N-S bytes of normal data which is a payload.
[134] FIG. 20 shows a dual TS packet including the stuffing region for
inserting the
known SRS signal for synchronization in the TS structure unit, according to
another
embodiment of the invention. Differently from the dual TS packet of FIG. 11,
78-packet turbo streams are inserted in 312-segment packets of one field of
the dual
TS. The dual TS is structured in a manner that 4 packets comprising 1 packet
(188
bytes) of the turbo stream and 3 consecutive packets (188 bytes) of the normal
streams
are repeatedly arranged at the rate of 1:3. When 70 packets of the turbo
streams are
inserted in 312 segments of the packets of the dual TS, on the other hand, the
dual TS
is structured in a manner that 4 packets comprising 1 packet (188 bytes) of
the turbo
streams and 3 consecutive packets (188 bytes) of the normal streams are
repeatedly
arranged 70 times, and the rest 32 packets comprise the normal stream packets.
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[135] FIG. 21 shows a dual TS packet including the stuffing region for
inserting the
known SRS signal for synchronization in the TS structure unit, according to
yet
another embodiment of the invention. Differently from the dual TS packet of
FIG. 11,
88-packet turbo streams are inserted in 312-segment packets of one field of
the dual
TS. The dual TS is structured in a manner that 4 packets comprising 2 packets
(188
bytes) of the turbo streams and 2 packets (188 bytes) of the normal streams
are
repeatedly arranged 10 times, and 4 packets comprising 1 packet (188 bytes) of
the
turbo stream and 3 consecutive packets (188 bytes) of the normal streams are
repeatedly arranged at the rate of 1:3 as shown in FIG. 9D.
[136] FIG. 22 shows a dual TS packet including the stuffing region for
inserting the
known SRS signal for synchronization in the TS structure unit, according to
still
another embodiment of the invention, which is a combined form of the dual TS
packets
shown in FIGS. 19 and 20. The dual TS packet is structured in a manner that 4
packets
are repeatedly arranged, the 4 packets comprising 1 packet (188 bytes) of the
turbo
stream, 1 packet of the normal stream wherein the SRS data and the turbo data
are
inserted in a part of the AF of the normal stream packet, and 2 packets (188
bytes) of
the normal stream packets.
[137] FIG. 23 shows the dual TS packet including the stuffing region for
inserting the
known SRS signal for synchronization in the TS structure unit, in the form of
segment
packets as shown in FIG. 19. Among 312-segment packets of one field of dual
TS, the
turbo data is inserted in a non-option field part of the packet including data
of the
option field. In FIG. 23, 'k' denotes a possible length (byte) of the SRS
data. In
addition, the turbo data is inserted next to the SRS data. Here, 'm' denotes a
possible
length (byte) of the turbo data.
[138] When dividing the 312 segments by 52-segment unit, location of the
option field
can be expressed as follows:
[139] Program clock reference (PCR) (using 6 bytes): 52n+15, n=0;
[140] Original program clock reference (OPCR) (using 6 bytes): 52n+15, n=1;
[141] Adaptation field extension length (using 2 bytes): 52n+15, n=2;
[142] Transport private data length (using 5 bytes): 52n+15, n=3, 4, 5; and
[143] The number of macro blocks (splice countdown) (using 1 byte): 52n+15,
n=0, 1, 2,
3, 4, 5.
[144] The "Transport private data length" among these, for example, exists
on the location
where n=3, 4, or 5.
[145] The dual TS in which the turbo data is inserted in the null data
except the option
field can be structured in various ways besides the above-introduced ways. Ad-
ditionally, the structural rate of the turbo data can be adjusted according to
the
structure of the dual TS packet.
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[146] FIG. 24 is a flowchart for explaining an example of a signal
processing method in
the digital broadcasting transmission system of FIG. 6. Referring to FIG. 24
and FIG.
6, the TS structure unit 300 receives the normal stream and the turbo stream,
generates
the second area for inserting the parity in the received turbo stream, and
multiplexes
the received normal stream and the turbo stream where the second area is
generated,
thereby structuring the dual TS (S1201). The randomizer 150 randomizes the
dual TS
output from the TS structure unit 300 (S1203). The parity area generator 110
generates
the first area for inserting the parity for en-or correction in the randomized
dual TS
(S1205). The first interleaver 120 primarily interleaves the dual TS where the
parity
area is generated (S1207), and the turbo processing unit 130 convolution-
encodes the
turbo stream included in the primarily interleaved dual TS and interleaves the
convolution-encoded turbo stream (S1209). The deinterleaver 140 deinterleaves
the
dual TS output from the turbo processing unit 130 (S1211). The RS encoder 210
inserts the parity in the first area of the deinterleaved dual TS (S1213).
[147] The second interleaver 220 secondarily interleaves the dual TS where
the parity is
inserted (S1215). The trellis-encoder 230 trellis-encodes the secondarily
interleaved
dual TS (S1217). The MUX 240 multiplexes the trellis-encoded dual TS by adding
the
segment sync and the field sync (S1219). The modulator 250 channel-modulates
the
multiplexed dual TS, up-converts the dual TS to a signal of a radio frequency
(RF)
channel band, and transmits the up-converted signal (S1221).
[148] FIG. 25 is a flowchart for explaining an example of a signal
processing method in
the turbo processing unit of FIG. 7. Referring to FIG. 25 and FIG. 7, the byte-
symbol
converter 131 converts the primarily interleaved dual TS from the byte form to
the
symbol form (S1301). The TS DE-MUX 132 demultiplexes the dual TS converted to
the symbol form into the normal stream and the turbo stream (S1303). The turbo
encoder 133 convolution-encodes the turbo stream of the demultiplexed dual TS
(S1305).
[149] Through the convolution-encoding, the parity with respect to the
turbo stream is ad-
ditionally generated and inserted in the second area of the turbo stream. The
turbo in-
terleaver 134 interleaves the convolution-encoded turbo stream (S1307). The
turbo
data MUX 135 multiplexes the interleaved turbo stream and the demultiplexed
normal
stream, thereby structuring the dual TS (S1309). The symbol-byte converter 136
converts the dual TS from the symbol form to the byte form (S1311).
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