Note: Descriptions are shown in the official language in which they were submitted.
CA 02624477 2008-04-02
1
WO 2007/043803 PCT/KR2006/004086
Description
METHOD FOR TURBO TRANSMISSION OF DIGITAL
BROADCASTING TRANSPORT STREAM, A DIGITAL
BROADCASTING TRANSMISSION AND RECEPTION
SYSTEM, AND A SIGNAL PROCESSING METHOD THEREOF
Technical Field
[11 Aspects of the invention relate to a method for turbo processing and
transmitting a
digital broadcasting transport stream, a digital broadcasting reception and
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 and reception 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
2
WO 2007/043803 PCT/KR2006/004086
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
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
CA 02624477 2008-04-02
3
WO 2007/043803 PCT/KR2006/004086
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
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
caused 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
and reception 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 a digital broadcasting signal,
comprising: preparing a first area for parity insertion with respect to a dual
transport
stream (TS) which includes a normal stream multiplexed with a turbo stream, in-
terleaving the dual TS which includes the first area, 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 turbo processing, deinterleaving the
turbo-
processed dual TS, transmitting the deinterleaved turbo-processed dual TS,
receiving
CA 02624477 2008-04-02
CA 02624477 2008-04-02
4
WO 2007/043803 PCT/KR2006/004086
the transmitted dual TS, demodulating the received dual TS, equalizing the de-
modulated dual TS, decoding the normal stream of the equalized dual TS to
recover a
normal data packet, and decoding the turbo stream of the equalized dual TS to
recover
a turbo data packet.
[12] According to one aspect of the invention, the method of processing a
digital
broadcasting signal, further comprises, before preparing the first area,
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.
[13] According to one aspect of the invention, the detecting the turbo
stream comprises
detecting the turbo stream by demultiplexing the dual TS which is interleaved,
encoding the detected turbo stream by inserting a parity with respect to the
detected
turbo stream into a second area created for parity insertion, interleaving the
encoded
turbo stream, and generating the dual TS by multiplexing the interleaved turbo
stream,
and the normal stream.
[14] According to one aspect of the invention, the detecting the turbo
stream further
comprises converting a basic unit of the interleaved dual TS from a byte to a
symbol,
and converting a basic unit of the generated dual TS from a symbol to a byte.
[15] According to one aspect of the invention, the transmitting of the
deinterleaved 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 interleaved dual TS, multiplexing by adding a synchronization
signal to
the trellis-encoded dual TS, and channel-modulating the multiplexed dual TS
and
transmitting a resulting stream.
[16] According to one aspect of the invention, the dual TS comprises a
field containing a
plurality of consecutive packets, 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,
and the
option field comprises 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/or an adaptation field extension length.
[17] 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.
[18] According to one aspect of the invention, the decoding the normal
stream comprises
decoding in which an error is corrected with respect to the normal stream of
the
equalized dual TS and the error-corrected normal stream is decoded,
deinterleaving the
normal stream which is decoded by the viterbi decoder, correcting an error of
the dein-
5
WO 2007/043803 PCT/KR2006/004086
terleaved normal stream, and recovering the normal data packet by
derandomizing the
en-or-corrected normal stream.
[19] According to one aspect of the invention, the decoding the turbo
stream comprises
turbo decoding the turbo stream of the equalized dual TS, deinterleaving the
turbo-
decoded turbo stream, Reed-Solomon decoding the deinterleaved turbo stream,
and de-
randomizing the Reed-Solomon decoded turbo stream.
[20] According to one aspect of the invention, the method of processing a
digital
broadcasting signal, further comprises, inserting a supplementary reference
sequence
in a stuffing area of the dual TS which includes a normal stream multiplexed
with a
turbo stream, and equalizing the demodulated dual TS using the supplementary
reference sequence retrieved from the stuffing area as compared to a
supplementary
reference sequence stored at a receiver.
[21] According to one aspect of the invention, the method of processing a
digital
broadcasting signal, further comprises, multiplexing the normal stream and the
turbo
stream to generate the dual TS, and preparing the stuffing area in the dual
TS.
[22] According to one aspect of the invention, the method of processing a
digital
broadcasting signal, further comprises, before the inserting the supplementary
reference sequence, randomizing the dual TS which has the stuffing area
therein.
[23] According to one aspect of the invention, multiplexing the normal
stream and the
turbo stream comprises preparing a second area for parity insertion with
respect to the
turbo stream.
[24] According to one aspect of the invention, the dual TS is in a 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.
[25] 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.
[26] 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, the stuffing area is at least a part of the
adaptation field
excluding the option field, and the option field comprises 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/or an
adaptation field extension length.
[27] 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,
CA 02624477 2008-04-02
6
WO 2007/043803 PCT/KR2006/004086
n=0,1,2,3,4,5.
[28] In another aspect of the present invention, a digital broadcasting
system comprises:
a transmission source 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 multiplexed with a turbo stream, 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, and a digital broadcasting receiver system comprising: a de-
modulator receiving a dual transport stream (TS) and demodulating the received
dual
TS, an equalizer equalizing the demodulated dual TS, a first processor
decoding the
normal stream of the equalized dual TS and outputting a normal data packet,
and a
second processor decoding the turbo stream of the equalized dual TS and
outputting a
turbo data packet.
[29] According to one aspect of the invention, the first processor
comprises, a viterbi
decoder correcting an error with respect to the normal stream of the equalized
dual TS
and decoding the en-or-corrected normal stream, a first deinterleaver
deinterleaving the
normal stream which is decoded by the viterbi decoder, a first Reed-Solomon
decoder
correcting an error of the normal stream which is processed at the first
deinterleaver,
and a derandomizer recovering the normal data packet by derandomizing the
error-
corrected normal stream, and the second processor comprises, a turbo decoder
decoding the turbo stream of the equalized dual TS, a second deinterleaver
dein-
terleaving the turbo-decoded turbo stream, a second Reed-Solomon decoder
decoding
the deinterleaved turbo stream, and a derandomizer derandomizing the Reed-
Solomon
decoded turbo stream.
[30] 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.
[31] According to one aspect of the invention, the dual TS comprises; a
field containing
a plurality of consecutive packets, an option field recording a predetermined
type of
packet information therein, is arranged in the packet at a predetermined
position of the
field which does not overlap with the turbo stream, and 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.
[32] According to one aspect of the invention, the digital broadcasting
system, further
CA 02624477 2008-04-02
7
WO 2007/043803 PCT/KR2006/004086
comprises, 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.
[33] 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.
[34] 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 a
pre-
interleaver interleaving the encoded turbo stream and providing the resultant
stream to
the duplicator.
[35] 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.
[36] According to one aspect of the invention, the transmission source
further comprises
an additional reference signal inserting unit receiving the dual TS, and
inserting an
additional reference signal in a stuffing area provided in the dual TS, and
the equalizer
equalizes the demodulated dual TS using the additional reference signal
extracted from
the stuffmg area in comparison with an additional reference signal stored at
the
receiver.
[37] According to one aspect of the invention, the digital broadcasting
system, further
comprises; a transport stream (TS) structure unit generating the dual TS by
mul-
tiplexing 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.
[38] 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.
[39] According to one aspect of the invention, the TS structure unit
further comprises a
CA 02624477 2008-04-02
8
WO 2007/043803 PCT/KR2006/004086
first Reed-Solomon encoder performing Reed-Solomon encoding with respect to an
externally-received turbo stream, and a pre-interleaver interleaving the
encoded turbo
stream and providing the resultant stream to the duplicator.
[40] 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 stuffmg area is at least a part of the adaptation field.
[41] According to one aspect of the invention, 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, the stuffing area is at least a part of the adaptation field
excluding the
option field, and the option field comprises 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/or an adaptation
field
extension length.
[42] 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,
n=0,1,2,3,4,5.
Advantageous Effects
[43] 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.
[44] 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.
[45] 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
CA 02624477 2008-04-02
CA 02624477 2013-02-13
30235-70
9
in form and details may be made therein without departing from the scope of
the invention
as defined by the appended claims.
Summary of the Invention
[45a] According to an aspect of the present invention, there is
provided a digital
broadcast receiver, comprising: a demodulator receiving and demodulating a
transport
stream in which a normal data, known data, and an additional data are
contained; an
equalizer equalizing the demodulated transport stream using the known data
which is
known previously between the digital broadcasting receiver and a digital
broadcasting
transmitter; and a turbo decoder performing turbo decoding of the additional
data in the
transport stream, wherein the transport stream is generated by, at a digital
broadcast
transmitter, encoding and interleaving the additional data and multiplexing
the additional
data with the normal data, and the additional data multiplexed with the normal
data is
interleaved with the known data.
145b1 According to another aspect of the present invention, there is
provided a
method for processing a stream in a digital broadcast receiver, the method
comprising:
receiving and demodulating a transport stream in which a normal data, known
data, and an
additional data are contained; equalizing the demodulated transport stream
using the known
data which is known previously between the digital broadcasting receiver and a
digital
broadcasting transmitter; and performing turbo decoding of the additional data
in the
interleaved transport stream, wherein the transport stream is generated by, at
a digital
broadcast transmitter, encoding and interleaving the additional data and
multiplexing the
additional data with the normal data, and the additional data multiplexed with
the normal
data is interleaved with the known data.
CA 02624477 2009-10-30
30235-70
9a
Brief Description of the Drawings
[461 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:
[47] 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;
[48] 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;
[49] FIG. 3 is a block diagram showing a digital broadcasting transmission
system
according to an embodiment of the invention;
[50] FIG. 4 is a block diagram provided to explain in detail the structure
of the digital
broadcasting transmission system of FIG. 3;
[51] FIG. 5 is a block diagram showing a transport stream (TS) constructing
unit of the
digital broadcasting transmission system of FIG. 4;
[52] FIG. 6 is a block diagram showing in detail the structure of a
transmitting unit of
the digital broadcasting transmission system of FIG. 4;
[53] FIG. 7 is a block diagram showing an example of a turbo processing
unit of the
digital broadcasting transmission system of FIG. 4;
[54] FIG. 8 is a block diagram showing the structure of a turbo encoder of
the turbo
processing unit of FIG. 7;
[55] FIGS. 9 through 15 show exemplary structures of a dual transport
stream packet of
the digital broadcasting transmission system of FIG. 4;
[56] 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;
[57] 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;
[58] FIG. 24 is a block diagram showing the structure of a digital
broadcasting reception
system according to an embodiment of the invention;
[59] FIG. 25 is a block diagram of a turbo decode of the digital
broadcasting reception
system of FIG. 24;
[60] FIG. 26 is a flowchart for explaining an example of a signal
processing method in
the digital broadcasting transmission system of FIG. 6;
10
WO 2007/043803 PCT/KR2006/004086
[61] FIG. 27 is a flowchart for explaining an example of a signal
processing method in
the turbo processing unit of FIG. 7;
[62] FIG. 28 is a flowchart for explaining an example of a signal
processing method in
the digital broadcasting reception system of FIG. 24; and
[63] FIG. 29 is a flowchart for explaining an example of a signal
processing method in
the turbo decoder of FIG. 25.
Best Mode for Carrying Out the Invention
[64] 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.
[65] 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-Generic coding of moving pictures and associated audio information:
Systems (second edition) (MPEG-2); and ISOJEC IS 13818-2:2000(E), Information
technology-Generic coding of moving pictures and associated audio information:
Video (second edition) (MPEG-2), the contents and disclosures of which are in-
corporated herein by reference. However, it is understood that aspects of the
invention
can be implemented 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".
[66] 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
CA 02624477 2008-04-02
11
WO 2007/043803 PCT/KR2006/004086
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.
[67] 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.
[68] 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.
[69] 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, internet 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.
[70] 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
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.
[71] 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
CA 02624477 2008-04-02
12
WO 2007/043803 PCT/KR2006/004086
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.
[72] 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.
[73] 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.
[74] 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.
[75] 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.
[76] 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
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.
[77] 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
CA 02624477 2008-04-02
CA 02624477 2013-02-13
30235-70
13
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.
[78] 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.
[79] 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 (A153)..
[80] 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.
[81] 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
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)
=
[82] An example of the byte-to-symbol table of table D5.2 is as follows:
[83]
14
WO 2007/043803 PCT/KR2006/004086
3y n'il).D I Se9nhin1 0 Segment 1 Se chit 2 S4g merit 2 S=pg
ri-Fen1 4
Tro II Is Byte. 13 Its Tr4.11IG Ery14. EIV, 7rol II.s P.fle BIti: Tre.I Ils
Pyle Blt9 liel Ils. Eyte Blt--,.
f.i 7.8 4 208 5.4 8 4 IP 3,2 0 616
1 .1:1 4 :':'. 7,6
i 1
1 i
1 1 1 7.0 5 200 5.4 3 41:6 2,2 1 617 1,0 5 512.3
7,6
2 2 2 7.13 6 210 5.4 10 414 2,2 2 616 1,0 8 83u
7,6
3 3 3 7, o 7 211 Z.4 11 41:. :7,2 f.k
..1C1 1,0 ...
4 4 4 7,0 8 212 ...4 0 418 :?.2 4 520 1,0 .. .. .
5 5 7.0 :3 213 5,4 1 417 2,2 5 621 1,0 ...
6 6 6 7,0 10 214 Z.4 2 418 22 6 6.7.2
1,0 ... ..
.
7 7 7 7,19 11 21 5 -r...4 9 410 ."?.,=,2
7 f;;D:?. 1 .0 ... ..
.
8 a 8 7.0 Ci 2.:4 f..4 4 408 :72 e. 512
1,0 ... .. ...
7.0 1 205 5.4 5 40g 2,2 g 613 1,0 ... ..
...
IC.. 10 10 7.13 2 206 5.4 6 410 2,2 1'
514 1 ..:, ... .. ...
11 11 11 7.0 3 207 .f..4 7 411 :7,2 11
,;-15.. 1..2 ... .. ...
12 0 V 5.4 4 208 3.2 8 412 1,C.. r... 524 7.5 ...
12. 1 1 5.4 5 20.3 3.2 g 413 1,0 1.62 5
7 ,6 . . . ... ...
... ...
7 7 5.4 11 215 3.2 3 41.3 1,0 7 631 7.6 ... ... ...
20. 8 8 5.4 0 204 3.2 4 4:,8 1,0 e. 632 7,6 ... ...
...
21 3 g 5.4 1 205 3.2 5 40.3' 1,0 g 633 7,6 ... ...
...
22 10 10 5,4 2 206 3.2 6 410 .1,0 1,) 634 7.6 ... ...
...
22, 11 11 5,4 3 207 3.2 7 411 1,0 1 1
1.8 7.Ã ... ... ...
24 0 i_. a24 208 1.0 6 420 7,8 0 6.24 5,4 ...
... ...
2.7- 1 1 3.2 5 2.:0:0 1.0 42:.1 7,0. 1 52!..
!..4 ... ... ...
51 7 7 3.2 11 215 1.0 3 427 7,6. ... ... ...
...
... ...
'525 8 3,2 ':.1 2(.4 1,0. -1 428 7,5 ...... ...
... ... ...
32.. =.]. g 32 1 205 1.0 5 42.3 7,6...
.. ..
.
34- 10 10 3.2 2 211E. 1.1:1 4307,... .... .
. .. .
..
35 11 11 732 3 207 1.0 7 431 7,6.. ... ...
.. ... ...
38,''... 0 1.0 4 216 7.6 6. 420 5,4 .... .
. .. .
..
37 1 1 1.1.k 5 217 7.8 g 421 5,4
..... ...
.. ... ...
. ... ...
47 ii 11 1,0' S 27 7,...=...
... ... ...
... ...
... ... ...
4.5. 2 12 7.3. 4 216 5.4.. .. ... ...
... . ...
40 1 19 7.1.:. 5 217 5..4
.... ..
.. ... ...
... . ...
=
=
== == = =-
... . . .
g 5 11 23 1.0 .... . . .
.. ... ..
... .
.. .
[841
24 7,8 ..... ... ...
. _.. ...
... .._ ...
. ... ... ..
1 25 7,8 ... ... ... ...
... ... ...
... ... ... ... ...
- -
--- === = == - = =-= - =
=-= === ===
7t.:7 11 1:.:.1 1,0 ..... -==
==-
... _ .. .._ . ... ...
... .._ ...
78.8 0 1::.2 7,6 _._
1 1:12 7,6 .... ...
...
.. ... ...
... ... ...
... ... ...
- "-
al 7, 11 .7.1:1:3 1.0 3 419 7,0 7 523 5,4 ii
827 3.2 ... ... ....
al; 0. 204 7,0 4 408 5,4 0 0.12 3,2 0 818. 1.0 ...
... ...
817 1 205 7,6 5 409 7.,4 0 813 2.,2 1 817 1.0 ... ...
...
... ...
627 11 215 7.5 :3 419 5,4 7 0.23 V 11 827
1.0 ... ... ..
[851 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
CA 02624477 2008-04-02
15
WO 2007/043803 PCT/KR2006/004086
recursive systematic convolutional (RSC) code, to insert parities in the
second parity
area.
[861 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
(PD),
and 184 bytes of turbo data.
[871 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.
[881 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 PD, and the turbo data of FIG. 9.
[891 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
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.
[901 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.
[911 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
CA 02624477 2008-04-02
16
WO 2007/043803 PCT/KR2006/004086
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.
[92] 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.
[93] 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.
[94] 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.
[95] When dividing the 312 segments into 52-segment units, the locations of
the option
fields can be expressed as follows:
[96] Program clock reference (PCR) (using 6 bytes): 52n+15, n=0;
[97] Original program clock reference (OPCR) (using 6 bytes): 52n+15, n=1;
[98] Adaptation field extension length (using 2 bytes): 52n+15, n=2;
[99] Transport private data length (using 5 bytes): 52n+15, n=3, 4, 5; and
[100] a number of macro blocks (splice countdown) (using 1 byte): 52n+15,
n=0, 1, 2, 3,
4, 5
[101] 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.
[102] 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
CA 02624477 2008-04-02
17
WO 2007/043803 PCT/KR2006/004086
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
supplementary 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.
[103] 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
will be called as a second Reed-Solomon encoder for the convenience in
explanation.
[104] 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.
CA 02624477 2008-04-02
18
WO 2007/043803 PCT/KR2006/004086
[105] 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.
[106] 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.
[107] 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.
[108] 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
trellis encodes the secondarily interleaved packet.
[109] 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.
[110] The trellis encoder 819 according to an embodiment of the invention
may include i)
CA 02624477 2008-04-02
19
WO 2007/043803 PCT/KR2006/004086
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.
[111] 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.
[112] 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
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 panty 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.
[113] 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.
[114] FIGS. 17 through 23 show the structure of a TS packet including the
SRS,
CA 02624477 2008-04-02
20
WO 2007/043803 PCT/KR2006/004086
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.
[115] 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.
[116] 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. 12.
[117] 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
CA 02624477 2008-04-02
21
WO 2007/043803 PCT/KR2006/004086
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.
[118] 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.
[119] When dividing the 312 segments by 52-segment unit, location of the
option field
can be expressed as follows:
[120] Program clock reference (PCR) (using 6 bytes): 52n+15, n=0;
[121] Original program clock reference (OPCR) (using 6 bytes): 52n+15, n=1;
[122] Adaptation field extension length (using 2 bytes): 52n+15, n=2;
[123] Transport private data length (using 5 bytes): 52n+15, n=3, 4, 5; and
[124] The number of macro blocks (splice countdown) (using 1 byte): 52n+15,
n=0, 1, 2,
3, 4, 5.
[125] The "Transport private data length" among these, for example, exists
on the location
where n=3, 4, or 5.
[126] 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.
[127] FIG. 24 is a block diagram showing a digital broadcasting reception
system
according to an embodiment of the invention. Referring to FIG. 24, the digital
broadcasting reception system comprises a modulator 1001, an equalizer 1003, a
first
processor 1050, and a second processor 1060. The digital broadcasting
reception
system receives the dual TS, demodulates the received dual TS, equalizes the
de-
modulated dual TS, Viterbi-decodes and deinterleaves the normal stream of the
equalized dual TS, RS-decodes the deinterleaved normal stream, and
derandomizes the
RS-decoded normal stream. The digital broadcasting reception system turbo-
decodes
and deinterleaves the turbo stream of the equalized dual TS, RS-decodes the
dein-
terleaved turbo stream, and derandomizes the RS-decoded turbo stream. The
modulator
1001 performs synchronization detection and demodulation with respect to the
baseband signal of the received dual TS. The equalizer 1003 compensates for
channel
CA 02624477 2008-04-02
22
WO 2007/043803 PCT/KR2006/004086
distortion generated by multipaths of the channel from the demodulated dual
TS,
thereby removing interference between the received symbols.
[128] The first processor 1050 includes a Viterbi decoder 1017, a
deinterleaver 1021, an
RS decoder 1023, and a derandomizer 1025. The Viterbi decoder 1017 performs
error
correction with respect to the normal stream of the equalized dual TS and
decodes the
en-or-corrected symbols, thereby outputting the symbol packet. The distributed
decoded packet can be rearranged by the deinterleaver 1021. The RS decoder
1023
performs en-or correction with respect to the deinterleaved packet. The
derandomizer
1025 derandomizes the packet en-or-corrected by the RS decoder 1023.
Accordingly,
the normal stream of the dual TS is restored.
[129] The second processor 1060 includes a turbo decoder 1005, a second
deinterleaver
1009, an RS decoder 1011, a derandomizer 1013, and a turbo DE-MUX 1015.
However, it is understood that the second processor 1060 need not include all
shown
elements, such as the turbo DE-MUX 1015, in all aspects of the invention. The
turbo
decoder 1005 turbo-decodes the turbo stream of the equalized dual TS. The
turbo
decoding is performed by trellis-decoding the turbo stream of the equalized
dual TS,
deinterleaving and convolution-decoding the trellis-decoded turbo stream,
frame-
formatting the convolution-decoded turbo stream, and thereby converting the
turbo
stream in the symbol form to the byte form.
[130] Meanwhile, the turbo decoder 1005 is capable of trellis-decoding the
normal stream
of the equalized dual TS. The trellis-decoded normal stream is converted from
the
symbol form to the byte form using a symbol-byte converter (not shown). The
converted normal stream is deinterleaved to remove the parity. The panty-
removed
normal stream is derandomized, thereby being restored.
[131] The deinterleaver 1009 deinterleaves the turbo-decoded turbo stream.
The RS
decoder 1011 removes the parity added to the deinterleaved turbo stream. The
de-
randomizer 1013 derandomizes the parity-removed turbo stream. The turbo DE-MUX
1015 demultiplexes the derandomized turbo stream. The turbo stream herein is
capable
of receiving the turbo data among the turbo stream demultiplexed and formatted
to the
frame form.
[132] FIG. 25 is a block diagram of the turbo decoder of the digital
broadcasting reception
system of FIG. 24. Referring to FIGS. 24 and 25, the turbo decoder 1005
comprises a
trellis decoder 2001, a turbo deinterleaver 2003, a turbo decoder 2005, a
turbo in-
terleaver 2007, a frame formatter 2009, and a symbol/bye converting unit 2011.
[133] The trellis decoder 2007 trellis-decodes the equalized dual TS.
According to this
embodiment, the trellis decoder 2007 may trellis-decode the turbo stream of
the dual
TS and also a soft decision turbo stream which is turbo-interleaved. The turbo
dein-
terleaver 2003 deinterleaves the trellis-decoded turbo stream. The turbo
decoder 2005
CA 02624477 2008-04-02
23
WO 2007/043803 PCT/KR2006/004086
convolution-decodes the deinterleaved turbo stream, thereby outputting a soft
decision
or a hard decision. "Soft decision" refers to a value including information on
a metric
of the turbo stream. For example, when the metric of the turbo stream is
"1"and when
the metric of the turbo stream results in "0.8" the soft decision value "0.8"
is output.
When the metric of the turbo stream results in "1" the hard decision, that is,
the turbo
stream, is output.
[134] The turbo interleaver 2007 interleaves the hard decision turbo stream
that is
convolution-decoded. The frame formatter 2009 formats the convolution-decoded
hard
decision turbo stream corresponding to the frame of the dual TS.
[135] The operation of the symbol/byte converter 2011 to convert the frame-
formatted
turbo stream from the symbol form to the byte form can be easily understood by
referring to Table D5.2 of the 'ATSC DTV standard (A/53)' as set forth above.
[136] FIG. 26 is a flowchart for explaining an example of a signal
processing method in
the digital broadcasting transmission system of FIG. 6. Referring to FIG. 26
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).
[137] 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).
[138] FIG. 27 is a flowchart for explaining an example of a signal
processing method in
the turbo processing unit of FIG. 7. Referring to FIG. 27 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
CA 02624477 2008-04-02
24
WO 2007/043803 PCT/KR2006/004086
(S1305).
[139] 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).
[140] FIG. 28 is a flowchart for explaining an example of a signal
processing method in
the digital broadcasting reception system of FIG. 24. Referring to FIG. 28 and
FIG. 24,
the demodulator 1001 detects and demodulates synchronization according to the
sync
added to the signal of the baseband of the received dual TS (S1401). The
equalizer
1003 compensates channel distortion generated by multipaths of the channel
from the
demodulated dual TS, thereby removing interference between the received
symbols
(S1403).
[141] The Viterbi decoder 1005 of the first processor 1050 performs en-or
correction with
respect to the normal stream of the equalized dual TS, decodes the error-
corrected
symbol, and outputs the symbol packet (S1405). The distributed decoded packet
is
rearranged by the deinterleaver 1009 (S1407). The RS decoder 1023 performs en-
or
correction with respect to the deinterleaved packet (S1409). The derandomizer
1025
derandomizes the packet error-corrected by the RS decoder 1023 (S1411). Ac-
cordingly, the normal stream of the dual TS is restored.
[142] The turbo decoder 1005 of the second processor 1060 turbo-decodes the
turbo
stream of the equalized dual TS (S1413). The turbo decoding is performed by
trellis-
decoding the turbo stream of the equalized dual TS, deinterleaving and
convolution-
decoding the trellis-decoded turbo stream, frame-formatting the convolution-
decoded
turbo stream, and thereby converting the turbo stream from the symbol form to
the
byte form. The deinterleaver 1009 deinterleaves the turbo-decoded turbo stream
(S1415). The RS decoder 1011 removes the parity added to the deinterleaved
turbo
stream (S1417). The derandomizer 1013 derandomizes the parity-removed turbo
stream (S1419). The turbo DE-MUX 1015 demultiplexes the derandomized turbo
stream (S1421). The turbo stream herein is capable of receiving the turbo data
among
the turbo stream demultiplexed and formatted to the frame form.
[143] FIG. 29 is a flowchart for explaining an example of a signal
processing method in
the turbo decoder of FIG. 25. Referring to FIG. 29 and FIG. 25, the trellis-
decoder
2007 of the turbo decoder 1005 trellis-decodes the equalized dual TS (S1501),
the
turbo deinterleaver 2003 deinterleaves the trellis-decoded turbo stream
(S1503), and
the turbo decoder 2005 convolution-decodes the deinterleaved turbo stream
(S1507),
thereby outputting soft decision or hard decision. Here, the soft decision
refers to a
CA 02624477 2008-04-02
25
WO 2007/043803 PCT/KR2006/004086
value including information on a metric of the turbo stream. For example, when
the
metric of the turbo stream is "1" and when the metric of the turbo stream
results in
"0.8", the soft decision value "0.8" is output. When the metric of the turbo
stream
results in "1" the hard decision, that is, the turbo stream is output. The
output soft
decision is interleaved through the turbo interleaver 2007 (S1505) and trellis-
decoded
for error correction. Therefore, the above processes are repeated until the
metric of the
turbo stream becomes "1" to output the hard decision. Details of turbo coding
per se
are not provided because they are well known in the art. Moreover, the
invention is not
limited to turbo coding, and aspects of the invention may use other types of
coding in
place of or in addition to turbo coding.
[1441 The frame formatter 2009 formats the convolution-decoded hard
decision turbo
stream corresponding to the frame of the dual TS (S1509). The symbol-byte
converter
2011 may convert the frame-formatted turbo stream from the symbol form to the
byte
form (S1511).
CA 02624477 2008-04-02
