KR20020093928A - Mapping arrangement for digital communication system - Google Patents

Abstract

The receiver receives the digital signal. The digital signal includes a frame of robust VSB data and ATSC data and further includes a map. The map includes information indicating the location of the robust VSB data and the ATSC data in the frame. The decoder of the receiver decodes the digital signal. The processor of the receiver processes at least one of the robust VSB data and the ATSC data according to the position information included in the map.

Description

[0001] MAPING ARRANGEMENT FOR DIGITAL COMMUNICATION SYSTEM [0002]

The US standard for digital televisions is known as 8VCB data (ATSC Digital Television Specification A / 53). This 8VSB data has a constellation that consists of eight possible symbol levels. The eight possible symbol levels in the VSB system are all in phase. However, in a QAM system, symbols are transmitted in a quadrature relationship.

The above-mentioned specifications specify the format and modulation of digital video and audio data. The transmission data is in the form of a symbol having three symbols representing two bits to be trellis encoded into three bits of trellis encode data. Each 3 bits of trellis encoded data is mapped to a symbol having a corresponding level of 8 levels. Reed / Solomon encoding and interleaving also increase the robustness of the transmission information.

Ancillary data (data different from digital video or audio data) is also transmitted on the digital television channel. These data are formatted and modulated according to standards in the same manner as video and audio data. A receiver made according to the 8VSB standard can read the packet identification (PIDS) that allows the receiver to identify between audio, video and ancillary data.

However, the robustness of the transmitted digital television signal is sufficient for digital television reception, but this robustness is not sufficient for the transmission of auxiliary data, in particular critical auxiliary data . Thus, one of the applications of the present invention is the transmission of ancillary data in a VSB format with an Outer that encodes additional robustness.

The auxiliary data transmitted in accordance with this application of the present invention is referred to as the robust VSB data (RVSB) in the present invention.

The present invention is a U.S. patent application No. 60 / 198,014 filed on April 18, 2000 and U.S. Patent Application No. 60 / 255,476 filed on December 13,

The present invention relates to transmission and / or reception of digital data.

The above and other features and advantages of the present invention will become more apparent from the detailed description of the present invention when taken in conjunction with the following drawings.

1 shows a robust VSB transmitter for transmitting robust data and ATSC data according to the present invention;

Figure 2 shows a standard ATSC receiver for receiving ATSC transmitted by the robust VSB transmitter of Figure 1;

FIG. 3 illustrates a robust VSB receiver for receiving robust VSB data transmitted by the robust VSB transmitter of FIG. 1; FIG.

4 is a more detailed illustration of the 2/3 rate encoder of FIG. 1;

Figure 5 illustrates mapping junctions performed by the maper of Figure 4;

Figure 6 shows the operation of the 2/3 fpd decoder of Figures 2 and 3;

7 illustrates another robust VSB transmitter for transmitting robust VSB data and ATSC data according to the present invention;

Figure 8 shows a standard ATSC receiver for receiving ATSC data transmitted by the robust VSB transmitter of Figure 7;

FIG. 9 illustrates a robust VSB receiver for receiving robust VSB data transmitted by the robust VSB transmitter of FIG. 7;

FIG. 10 shows a circuit for generating an appropriate control signal on the dispatch control line of FIG. 9; FIG.

11 is a diagram illustrating another robust VSB transmitter for transmitting robust VSB data and ATSC data according to the present invention;

12 illustrates an example of four data segments including half rate outer code data to be transmitted by a robust VSB transmitter according to the present invention;

FIG. 13 is a diagram illustrating an example of four data segments including 1/4 rate outer code data to be transmitted by a robust VSB transmitter according to the present invention; FIG.

13 illustrates an example of 4 data segments including 3/4 rate outer code data to be transmitted by a robust VSB transmitter in accordance with the present invention;

FIG. 15 is a more detailed view of the interleaver Ir of FIGS. 1, 9 and 11; FIG.

FIG. 16 is a diagram illustrating deinterleavers Dr of FIGS. 3 and 9; FIG.

17 shows a map defining structure of a first robust VSB data packet of a frame;

Figure 18 shows a portion of a frame sync segment of a frame that performs map display that may be found in frame robust VSB data;

Figure 19 illustrates an extended slice predictor in accordance with one embodiment of the present invention;

FIG. 20 shows a trellis for the inner decoder of FIG. 19; FIG.

FIG. 21 shows possible state transitions for the outer decoder of FIG. 19; FIG. And

22 is a diagram illustrating an extended slice predictor according to another embodiment of the present invention.

A method according to one aspect of the present invention further includes a map including robust VSB data and causing the receiver to process the robust VSB data, wherein the robust VSB data is a digital signal And processing the replica of the robust VSB data and the map in correspondence with the map.

According to another aspect of the present invention, an apparatus according to another aspect includes a receiver, a decoder, and a prescer. The receiver receives a digital signal comprising frames of first and second 8-VSB data. The first and second VSB data have different bit rates. The digital signal further includes a map that includes information indicating at least one location of the first and second 8VSB data in the frame. The decoder decodes the digital signal. The processor processes the first 8VSB data according to the position information included in the map.

According to yet another aspect of the present invention, an electrical signal comprises a map, a first data symbol and a second data symbol. The first and second data symbols have the same arrangement and have a different bit rate and the first and second data symbols are intermixed with each other in a data frame and the map includes at least one of the first and second 8VSB data As an electric signal.

According to another aspect of the present invention, an apparatus according to the present invention includes a receiver, a decoder, and a processor. The receiver receives a digital signal and the digital signal comprises a frame of first and second 8VSB data. The first and second 8VSB data have the same arrangement and the first and second 8VSB data have different bit rates. The digital signal further includes a map, and the map includes information indicating a position of the first 8VSB data in a frame. The decoder decodes the digital signal. The processor processes the first VSB data that has discarded the second VSB data.

According to yet another aspect of the present invention, an apparatus of the present invention includes a receiver and first and second processors. The receiver receives a digital signal and the digital signal comprises robust VSB data, ATSC data, or a frame of these quantum data. The ATSC data has at least a packet identification (PID) number associated therewith. The digital signal further includes a map, which includes information indicating the location of the robust VSB data in the frame. The first processor processes the robust VSB data based on the map. The second processor processes the ATSC data based on the PID number.

RVSB and ATSC data transmission and reception

1 shows a robust VSB transmitter 10 that transmits both ATSC data and robust VSB data in accordance with an embodiment of the present invention.

Figure 2 shows a standard ATSC receiver 12 that receives ATSC data transmitted by a robust VSB transmitter 10 and Figure 3 shows a standard ATSC receiver 12 that receives robust VSB data transmitted by a robust VSB transmitter 10, And a robust VSB receiver 14.

Robust VSB transmitter 10 includes a Reed-Solomon encoder 16 that encodes an uncoded ancillary data byte by adding a lead / solomon parity byte to an uncoded (or uncoded) ancillary data byte. The unencoded ancillary data bytes and the Reed / Solomon parity bytes are interleaved by the interleaver 18. The interleaved unencoded ancillary data bytes and the Reed / Solomon parity bytes are then bit-coded by the outer coder 20 using either a convolutional code or another error correcting code. The out code 20 converts the unencoded ancillary data byte and the lead / solomon parity pair into a robust data byte (hereinafter referred to as a robust VSB data byte) and a lead / solomon parity byte, Thereby improving the robustness of the data bytes and the read / solomon parity pairs.

The outer coder 20 may include, for example, a half rate coder that generates two output bits for one input bit, a quarter rate coder that generates four output bits for one input bit, And may be a 3/4 rate coder that generates four output bits for three input bits.

At the output of the outer coder 20, a three byte transmit (tx) header is added to each group of robust VSB data and Reed / Solomon bytes encoded to form a robust VSB data packet. Multiplexer 24 multiplexes these robust VSB data packets with ATSC data packets (typically video and audio) each having a 3-byte transport header and 184 bytes of ATSC data packets. The inputs to the multiplexer 24 may be selected on a packet by packet basis and each selected input is supplied to the ATSC transmitter 26. [ The selection by the multiplexer 24 to be input to the ATSC transmitter 26 is based on the robust VSB map described below.

The ATSC transmitter 26 includes a Reed / Solomon encoder 28, an interleaver 30, and a 2/3 rate inner encoder 32, all operating in accordance with the ATSC standard, as is typical.

A standard ATSC receiver, such as the standard ATSC receiver 12 shown in FIG. 2, receives and processes ATSC data and discards the robust VSB data. Thus, the standard ATSC receiver 12 includes a 2/3 rate inner decoder 34, a deinterleaver 36 and a Reed / Solomon decoder 38, all of which operate in accordance with the ATSC standard. However, the standard ATSC receiver 12 is programmed to decode the ATSC data and the robust VSB data transmission header (which includes packet identifications or PIDS and is not encoded by the out-decoder 20). All of the ATSC receivers 12 read the PIDs of the packets and discard those packets with the PIDs of the robust VSB data at 40. The standard ATSC receiver also includes a slice predictor 42 (such as the slice predictor disclosed in U.S. Patent No. 5 / 923,711) that responds to the inner decoding data and returns the output to the phase tracker and / or equalizer, as in the known art. .

The robust VSB data packet may be received, decoded and processed by the robust VSB receiver, such as the robust VSB receiver 14 shown in Fig. 4, and as is known, the 2/3 rate inner encoder 32 of the ATSC transmitter 26 includes a precoder 44 and a 4-state trellis encoder 46. The 4- The combination of pro-recorder 44 and 4-state trellis encoder 46 generates 2 trellis coded output bits (Z ₀ , Z ₁ , Z ₂ ) for each of the 2 input bits (X ₁ , X ₂ ) State coder. ≪ / RTI >

The mapper 48 maps the tristimulus-coded output bits to symbols having one of the 8 levels shown in Fig. As is well known from the convolutional code theory, the operation of the pro-recorder 44 and the 4-state trellis encoder 46 can be regarded as an 8-state 4-ary trellis.

Therefore, the 2/3 rate inner decoder 50 in the robust VSB receiver 14 is a 4-state trellis encoder 46 of the 2/3-rate inner decoder 32 as shown in FIG. 6, (See, for example, " Optimum Soft Output Detection for Channels With Intersymbol Interference ", Li, Vucetic, and Sato, IEEE Transactions On Information Theory, May 1995 To generate a soft output Decision. Such an operation for soft decision making is more complicated than a widely used viterbi algorithm for generating a hard decision output, but the operation of making a soft decision is performed by the outcoder 20 Takes full advantage of the coding gain provided.

The output of the 2/3 raid inner decoder 50 is inversely interleaved by the de-interleaver 52. The robust VSB receiver 14 reads the PIDs of all packets at the output of the de-interleaver 52. Based on these PIDs, the robust VSB receiver 14 discards these packets with PIDs of the ATSC data at 54 and also by the transport header added after the outcoder 20 and the Reed / Solomon encoder 28 Discard the added parity byte. Thus, the robust VSB receiver 14 passes only the VSB data packet containing the robust VSB data encoded by the outcoder 20 at 54. The robust VSB data packet is decoded by the outer decoder 56 and deinterleaved by the de-interleaver 58 (serving as the interleaver 18), and re-interleaved by the Reed / Solomon decoder 56 Robust VSB data decoded by the decoder 60 is supplied to the read / solomon encoder 16 of Fig.

The reliable output of the out decoder 56 (either soft or hard output may be used) is fed back to the interleaver 62 (interleaver 62) in the feedback path 64 to recover the procedure of the out- (Which corresponds to the first half 30). The interleaved outer decoded data in this way can be used by the slice predictor 66 to create a reliable feedback with, for example, a phase tracker and / or an equalizer. However, the overall feedback delay introduced by the de-interleaver 52 and the interleaver 62 within the robust VSB receiver 14 is generally too long to provide useful feedback to the phase tracker and / or equalizer.

The apparatus shown in Figures 7, 8 and 9 avoids the feedback delay introduced by the de-interleaver 52 and the interleaver 62 of the robust VSB receiver 14. 7 shows an example in which the uncoded ancillary data bytes are encoded by the read / solomon encoder 82, and the read / solomon encoder 82 adds the read / solomon parity bytes to the uncoded ancillary data bytes. The unencoded ancillary data bytes and the Reed / Solomon parity bytes are interleaved by the interleaver 84. The interleaved uncoded ancillary data bytes are then bit-coded by the outer coder 86 using either a convolutional code or a turbo product code. The bit-wise output of the outer coder 86 is interleaved into small blocks by a small block interleaver 88 to mitigate the impact of channel burst errors in the outer decoder. The data provided by the small block interleaver 88 is referred to as Rdata (n.o), which refers to the robust VSB data in the normal sequence.

(I) a valid 3-byte transport header with a PID number for the robust VSB data, (ii) dummy robust VSB data 184 placeholder bytes, and iii) receive ATSC format packets each having 20 placeholder bytes for pseudo ATSC lead / solomon parity data. The other input of the first multiplexer 92 receives the ATSC format pseudo-packet comprising 207 bytes of pseudo ATSC data, respectively. These ATSC format pseudo-packets act as placeholders so that real ATSC packets are appended downstream. The input of the first multiplexer 92 can be selected on the packet by the packet basis, and this selection is based on the robust VSB map as described below.

The selected outputs of the first multiplexer 92 are interleaved by an interleaver 94 in accordance with the ATSC standard for convolution byte interleaving. A data replicator 96 receives both the output of the interleaver 94 and the output of the small block interleaver 88. The data replicas 96 replace each pseudo robust VSB data placeholder byte from the interleaver 94 with the next normal level robust VSB data byte from the small block interleaver 88.

The output of the data replicas 96 includes normalized robust VSB data with interspersed transport header pseudo ATSC lead / solomon parity bytes, and pseudo ATSC data packet bytes.

The deinterleaver 98, which operates in accordance with the ATSC standard for byte interleaving, deinterleaves the output of the data replicators 96 to generate a packet of the transport header, reordering robust VSB data Rdatd (r, o) &Quot; repacketize " data such as ATSC lead / solomon parity bytes and pseudo ATSC data. The reordering of the normally reordered robust VSB data results from the result of the de-interleaving of the de-interleaver 98 and the re-ordered data is referred to herein as the reordered robust VSB data.

The pseudo ATSC lead / solomon parity bytes (20 bytes per packet) and pseudo ATSC data packets (207 bytes per packet) of the robust VSB packet are discarded at 100.

The remaining robust VSB packets, each containing a transport header and reordered robust VSB data, are multiplexed by the second multiplexer 102 into a real ATSC data packet, each containing 187 bytes of transport header and ATSC data. Any input to the second multiplexer 102 can be selected in the packet by the packet basis and supplied to the ATSC transmitter 104. The preamble by the second multiplexer 102, which is input and passes to the ATSC transmitter, is based on the robust VSB map described below.

The ATSC transmitter 104 typically includes a Reed / Solomon encoder 106, an interleaver 108 and a 12-way 2/3 rate inner encoder 110, all operating in accordance with the ATSC standard. The Reed / Solomon encoder 106 outputs transmission headers multiplexed into a packet of a transport header, ATSC data and ATSC lead / solomon parity bytes, reordering robust VSB data, and packets of an ATSC lead / solomon parity byte. The ATSC lead / solomon parity bytes for the robust VSB data are computed based on the reordered robust VSB data. The interleaver 108 also changes the procedure of the robust VSB data so that the robust VSB data at the output of the interleaver 108 is robust VSB data that is normally rearranged again.

The interleaver 108 also distributes the transmit header, the ATSC lead / Solomon parity byte, and the ATSC data. This data is encoded and transmitted at a 2/3 rate by the 12-way 2/3 rate inner encoder 110. The transmitted robust VSB data is in a normal procedure, that is, a procedure provided at the output of the small block interleaver 88. This normal procedure allows the robust VSB receiver to avoid the delay caused by the de-interleaver 52 and interleaver 62 of the robust VSB receiver 14. [

As shown in FIG. 8, the sub-ATSC receiver 120 includes a normal transmission procedure with an ATSC lead / solomon parity byte located according to the ATSC convolutional byte interleave provided by the ATSC data interleaver 108, And a 12-way 2/3 inner decoder 122 for encoding the transmitted data to provide an output data stream having robust data. The ATSC de-interleaver 124 restores the transport header, ATSC data, and ATSC lead / solomon parity bytes to their transported " packetized " The ATSC de-interleaver 124 also converts the normalized robust VSB data into the re-arranged robust VSB data. This reordered format allows for correctly testing the parity for the ATSC lead / Solomon decoder 126 and the robust ATSC data packet of the sub-ATSC receiver 120. And the standard ATSC receiver 120 can read the robust VSB data packet transmission header and appropriately discard the robust VSB data packet at 128 based on their PID.

As shown in FIG. 9, the robust VSB receiver 130 includes a soft output 12-way 2/3 rate inner decoder 132. Hard 2/3 decoders cause significant loss of coding gain. The output of the soft output 12-way 2/3 rate inner decoder 132 is the ATSC lead / solomon parity distributed in the robust VSB data at the locations indicated by the reordered ATSC data transmission header and the dispatch control line 134, Normalized robust VSB data with symbols. Under control of the dispatch control line 134, the dispatch block 136 discards the reordered ATSC data, the transport header and the ATSC Reed / Solomon parity symbol.

The small block de-interleaver 138 de-interleaves the robust VSB data. The small block de-interleaver 138 has a relatively low delay time. This de-interleaving distributes possible burst errors within the robust VSB data at the output of the soft output 12-way 2/3 rate inner decoder 132. The normal procedure robust VSB data is also decoded bit-by-bit by an outer decoder 140 that bundles the robust VSB data into bytes. Amp information is provided to the outer decoder 140 at the R _MAP data input to inform the outer decoder 140 of what decoding rate is used for some data. Neither the de-interleaver 52 nor the interleaver 62 is needed in the robust VSB receiver 130 to allow for a lower overall feedback delay with the phase tracker and / or equalizer. The outer decoded data may be used by the extended slice predictor 142 to generate feedback with, for example, a phase tracker and / or an equalizer. If necessary, the feedback may be controlled by a gate or the step size of the equalizer gradient algorithm may be adjusted in proportion to the reliability of the decoded data.

The robust VSB data packet payload decoded by the outer decoder 140 is deinterleaved to reconstruct the original uncoded unsupported data supplied to the Reed / Solomon encoder 82 of FIG. 7, Solomon decoding by the decoder 146 (corresponding to the lead / Solomon encoder 82).

As defined in the ATSC standard, the frames each comprise a plurality of segments including a preset number of bytes. The first segment of the frame is a frame sync segment and the remaining segments in the frame are data segments. Although the robust VSB data may be transmitted in segments or segments, it is convenient to transmit the robust VSB data in a segment pair. The robust VSB map described above indicates which segment pair contains robust VSB data to discard correctly reordered ATSC data in diskette block 136 before the reordered ATSC data can reach outer decoder 140 . The transport header and ATSC lead / solomon parity data (VSB and ATSC) for all segments must also be discarded by the diskette block 136.

10 shows a conceptual simple circuit for generating appropriate control signals on the dispatch control line 134 to control such a discard function and also showing the relevant parts of the robust VSB receiver 130. In FIG. The robust VSB receiver 130 uses the received map information (how to transmit and receive such map information will be described later) to instruct the pseudo-segment generator 150 when to configure the pseudo 207 byte segment. The pseudo-segment generator 150 also uses a frame sync signal. For each ATSC pseudo-segment, pseudo-segment generator 150 sets all bytes to FF. For each robust VSB data pseudo segment, the pseudo segment generator 150 sets the transmit header and the ATSC lead / solomon parity byte to FF. Pseudo-segment generator 150 sets the remaining bytes of each robust VSB data pseudo-segment to 00.

These pseudo segments are supplied by the pseudo segment generator 150 to the ATSC convolution line byte interleaver 152 where the output of the interleaver 152 is used to control the discrete block 136, (136) correctly discards the reordered ATSC data, the transmit header, and the ATSC lead / solomon parity data interleaved in the received data stream in response to the FF and 00 codes. Thus, the discrete block 136 passes only the robust VSB data.

FIG. 11 shows a multiple outer code robust VSB transmitter 160. The robust VSB transmitter 160 operates similarly to the robust VSB transmitter 160 of FIG. The robust VSB transmitter 160 includes a first Reed-Solomon encoder 162 for encoding the first non-encoded ancillary data by adding a Reed / Solomon parity byte to the first non-encoded ancillary data, a Reed / A second Reed-Solomon encoder 164 for encoding the second non-encoding ancillary data by adding the second non-encoding ancillary data to the Solomon parity byte and a Reed-Solomon encoder 164 for encoding the third non-encoding ancillary data And a third Reed / Solomon encoder 166. The read / solomon encoded data of the first non-encoded auxiliary data is interleaved by the first interleaver 168, the read / Solomon encoded data of the second non-encoded auxiliary data is interleaved by the second interleaver 170, The read / solomon encoded data of the third non-coded auxiliary data is interleaved by the third interleaver 172. Then, the first non-coded auxiliary data interleaved Reed-Solomon coded data is coded bit by bit by the first outer coder 174 and the interleaved Reed-Solomon coded data of the second non-coded auxiliary data is coded by the second outer coder 174. [ And the interleaved Reed-Solomon encoded data of the third non-encoded auxiliary data is encoded bit-by-bit by the third outer coder 180. [

The bit output of the first outer coder 174 is interleaved by the first small block interleaver 180 and the bit output of the second outer coder 176 is interleaved by the second small block interleaver 182, The bit output of the outer coder 178 is interleaved by the third small block interleaver 184.

The first outer coder 174 is a 1/4 rate coder, the second outer coder 178 is a half rate coder, and the third outer coder 178 is a 3/4 rate coder. However, combinations of these or other outcoder employing different coding rates may be used.

The data outputs of the first, second and third small block interleavers 180, 182 and 184 are selected by the multiplexer 186 under the control of a selection input which determines the order in which the other out- do. The data at the output of the multiplexer 186 is referred to as Rdata (n.o) representing the normal procedure robust VSB data, as described above. The top three inputs of the multiplexer 190 are a valid 3-byte transmit header with a PID number for robust VSB data, 184 place holder bytes of pseudo-robust VSB data, and 20 pseudo-place holder bytes for ATSC lead / solomon parity data Lt; RTI ID = 0.0 > ATSC < / RTI > The robust VSB data at the top input of the multiplexer 190 corresponds to the 1/4 rate coded data from the first outer coder 174 and the robust VSB data at the next input of the multiplexer 190 is the second outer And the robust VSB data at the next input of the multiplexer 190 corresponds to the 3/4 rate encoded data from the third outer coder 178. [ The data supplied to the lowest input of the multiplexer 190 comprises ATSC format pseudo-packets each having 207 bytes of pseudo ATSC data. These pseudo ATSC data packets are used as placeholders for the real ATSC data packets to be added downstream of the multiplexer 190. The input to the multiplexer 190 may be selected on the packet by the packet basis in accordance with the input on the selection line. This selection is based on the robust VSB data map described below.

The output of multiplexer 190 is interleaved by interleaver 192 to achieve correct ATSC convolutional line interleaving. The data replicas 194 receive both the output of the interleaver 192 and the output of the multiplexer 186. The data replicas 194 receive both the output of the interleaver 192 and the output of the multiplexer 186. Data replicas 194 replace each pseudo robust VSB data placeholder byte from multiplexer 190 with the next corresponding normal level robust VSB data byte from multiplexer 186. [

The output of the data replicas 194 is the normal level of robust VSB data (suitably 1/4 rate encoding, 1/2 rate, and so on) with sparse transmission header, pseudo ATSC lead / solomon parity byte and pseudo ATSC data packet byte Encoding and / or 3/4 rate encoding index). The convolutional byte byte deinterleaver 196 (as described in the ATSC specification) deinterleaves the output of the data replicators 194 to deinterleave the packets of the transport header, the reordered robust VSB data (1/4, 1/2, And / or 3/4 rate coded data) and pseudo-packets of ATSC data. The reordering of the normal level of robust VSB data results from the de-interleaving of the de-interleaver 190.

Pseudo ATSC lead / Solomon parity bytes, (20 per packet) and pseudo ATSC data packets (207 bytes per packet) are similar to those provided by dispatch control line 134 and dispatch block 136 of FIG. 9 . The remaining robust VSB packets, each including the transport header and the robust VSB data of the reordering, are multiplexed by the multiplexer 200 with a real ATSC data packet each containing 187 bytes of transport header and ATSC data. The input to the multiplexer 200 is selected on the packet by the packet basis and supplied to the ATSC transmitter 202.

The selection by the multiplexer 200, which is entered and passed to the ATSC transmitter 202, is based on the robust VSB map described below.

The ATSC transmitter 202 typically includes a Reed / Solomon encoder 204, an interleaver 206 and a 12-way 2/3 date inner encoder 208, all operating in accordance with the ATSC standard. The Reed-Solomon encoder 204 outputs a packet of transport headers multiplexed into a packet of a transport header, ATSC data and ATSC lead / solomon parity bytes, reordered robust VSB data, and a packet of an ATSC lead / Solomon parity byte. The ATSC lead / solomon parity bytes for the robust VSB data are calculated for the robust VSB data of the reordering. Furthermore, the interleaver 206 changes the procedure of the robust VSB data so that the robust VSB data at the output of the interleaver 206 is again normal robust VSB data. In addition, the interleaver 206 distributes the transmission header byte, the ATSC lead / Solomon parity byte, and the ATSC data.

These data are encoded and transmitted at a 2/3 rate by a 12-way 2/3 rate inner encoder 208.

The transmitted robust VSB data is in a normal procedure, that is, a procedure provided at the output of the multiplexer 186. This normal data procedure allows the robust VSB receiver to avoid the delays caused by the deinterleaver 52 and the interleaver 62.

As described above, the ATSC frame has a frame sync segment and a plurality of data segments, and the robust VSB data is packetized into a group of four segments for convenience.

More specifically, FIG. 12 shows an example of four data segments that can be used in a frame to transmit half rate encoded robust VSB data.

FIG. 13 shows an example of four data segments that can be used in a frame to transmit the 1/4 rate encoded robust VSB data, and FIG. 14 shows an example of a 4 / Lt; RTI ID = 0.0 > 4 < / RTI >

These examples illustrate a frame preceding the interleaver 108 and each assume 184 bytes in length, 20 of which include a robust / Solomon encoded block of integer parity bytes.

For the case of a 1/2 rate outer code, FIG. 12 shows that the outcoder outputs two bits for each input bit. The robust VSB data packet is used as a RVSB lead / solomon block for a pair of data segments (one bit per symbol) so that for a half rate outter god, the four segments include two robust / solomon encoded blocks Packet. As shown in Fig. 13, in the case of the 1/4 rate outer code, the outer coder outputs 4 bits for each input bit. The robust VSB data has one RVSB lead for each of the four data segments (1/2 bit per symbol) so that for a quarter rate outer code, the four segments include one robustread / solomon encoded block. / Solomon block. As shown in Fig. 14, in the case of the 3/4 rate outer code, the outer coder outputs 4 bits for each of the 3 input bits. In this case, the transmitted symbols and byte boundaries are not always matched. However, the three complete RVSB Reed / Solomon blocks compress exactly four data segments (1.5 bits per symbol) for the 3/4 rate outer code, so that the four segments include three robust / solomon encoded blocks . 12, 13 and 14 can be represented as the following table.

S X Y 1/2 One 2 1/4 One 4 3/4 3 4

Where X denotes the number of complete robustread / syllable encoded blocks and Y denotes the number of frame segments required to contain the corresponding number (X) of the Robustrild / Solomon encoded blocks.

However, it should be noted that different coding rates may be used in connection with the present invention, and thus the table will vary depending on the particular coding rate used.

The interleavers 18, 84, 168, 170, and 172 are shown in more detail in FIG. 15 to illustrate that the Roberstream / Solomon encoded blocks are selected with a length of 184 bytes and the de-interleavers 58, Is shown in more detail. The interleavers 18, 84, 168, 170 and 172 are convolutional line interleavers with B = 46, M = 4, N = 184 interleaving the robust VSB data on a byte by byte basis. The structure of such an interleaver is similar to that of the ATSC digital television specification A / 53 and the ATSC digital television specification A / 54 except that the B parameter for the robust interleaver is 46 instead of 52 and the parameter N is 184 instead of 208 It is the same as the ATSC interleaver structure described in the guide. Such an interleaver is required so that the robust VSB receiver can overcome a long noise burst in the channel even if the ATSC deinterleaver Da is bypassed as shown in FIG. As shown in FIG. 16, the de-interleavers 58 and 144 are convolution line interleavers with B = 46, M = 4, N = 184 for de-interleaving the robust VSB data byte by byte. The structure of such an inverse interleaver is also similar to that of the ATSC Digital Television Specification A / 53 and ATSC Digital Television Specification A / 54 except that the B parameter for the robust inverse interleaver is 46 instead of 52 and the parameter N is 184 instead of 208 It is the same as the ATSC reverse interleaver structure described in the Usage Guide.

Since the robust VSB lead / Solomon block has 184 bytes and the constants of the robust VSB lead / Solomon block are data frames, the number of robust VSB data bytes in one data frame plus the robust VSB lead / Parity bytes can always be evenly divided by 46. Thus, the frame sync segment may be used as a synchronization device for the de-interleaver 58, 144 (Dr) at the receiver regardless of the value of G (described below). In frame synchronization, the deinterleaver commutators are placed in the top position. The de-interleavers 58 and 144 are de-interleaved on a byte-by-byte basis.

Data mapping

As discussed above, each data frame may comprise a mixture of robust VSB data segments and ATSC (non-robustly encoded) data segments.

Furthermore, the robust VSB data may include data encoded with a mixture of coding rates. The robust VSB receivers 14 and 130 are robust VSBs in which the segments are coded so that the robust VSB receivers 14 and 130 correctly process the robust VSB data to discard the ATSC data, It must have a robust VSB map indicating whether it is used for coding. The robust VSB transmitter 10, 80, 160 also uses the robust VSB map to control their corresponding multiplexing and discarding functions. This robust VSB map is transmitted by the robust VSB transmitter 10, 80, 160 to the robust VSB receiver 14, 130 in accordance with all other data in the manner described below.

The presence, amount and location of the robust VSB data within a data frame encoded with a particular outline code is represented by one or more numbers Sc appearing as two-level data in the frame sync segment of the data frame. As is known, the frame sync segment is the first segment in the frame. Therefore, for the above described outer codes (1/4 rate, 1/2 rate and 3/4 rate), the frame sync segment should preferably include [S1 / 4, S1 / 2, S3 / 4].

Each Sc (equal to S1 / 4 or S1 / 2 or S3 / 4) is encoded as 18 symbols (bits) of two-level data. For all three codes, a total of 3 x 18 = 54 symbols is required as the definition of the robust VSB map. These symbols are inserted into the spare area near the end of each frame synchronizing segment (immediately before the 12 preceding bits). For each group of 18 bits (b ₁₈ ... b ₁ ), the last six bits (B ₆ ... b ₁ ) are the 8 segments (8 segments according to the outer code = 2 , 4 or 6 robust VSB data packets). The 12 leading bits are for comb filter compensation (see the ATSC Digital Television Specification A / 54 User Guide). Therefore, the cost, the bit b ₆ ‥‥ b ₁ is (G) represents a, the bit b ₁₈ b ₁₃ is ‥‥ complement (complement) of the bit b ₆ ‥‥ b _1, as shown in Figure 18, the bit b ₁₂ ..., b ₇ may represent alternating +1 and -1 (or any other pattern).

S = S _1/4 + S _1/2 + S _3/4 .

Since 312/8 = 39, 0 to 39 groups of 8 segments can be mapped as robust VSB data or 8VSB data (ATSC data). Therefore, as long as their sum S is S? 39, each Sc can have a value of 0? 39.

It is desirable that the robust VSB data segments be evenly distributed as long as possible over the data frame. For example, if S = 1 then the next 8 segments are mapped as robust VSB data segments and all other segments are mapped as ATSC data segments: 1, 40, 79, 118, 157, 196, 235 and 274.

If S = 2, then 16 segments are mapped as robust VSB data segments: 1, 20, 39, 58, 77, 96, 115, 134, 153, 172, 191, 210, 229, 248, 267 and 286. These examples continue until S = 39, and the entire data frame is mapped as a robust VSB data segment. For any value of S, the spacing between the pairs of robust VSB data segments is not completely uniform. However, the interval is predetermined for any value of S, and therefore notifies all receivers.

If the frame includes robust VSB data provided by a three outer coder operating at 1/4 rate, 1/2 rate, and 3/4 rates, then the data from these outcoder are, for RVSB segments, The 8 x S _1/4 segment contains 1/4 rate outer-coded data, then the 8 x S _1/2 segment contains 1/2 rate outer-coded data, and the final 8 x S _3/4 segment contains And 3/4 rate outer-coded data. However, other robust VSB data segment combinations are possible for any of these three outcoder or other types of outcoder.

Since the robust VSB map continues in the frame sync segment, as described above, the robust VSB map can not obtain the same coding gain level as the robust VSB data. However, the robust VSB map can still be reliably obtained by the robust VSB receiver by correlating the robust VSB map to any number of frames. Therefore, the robust VSB map should not be changed too frequently (for example, every 60 frames or more).

The mapping method described above allows the receiver to reliably and simply obtain the robust VSB map by correlation. Once the receiver has acquired the map, it is desirable that this receiver immediately and reliably tracks changes in the map. The definition in the robust VSB map for each outer code containing comb-like compensation bits is replicated in the first robust VSB lead / solomon coding block of the frame to immediately and reliably track changes in the map. There are also (i) future map changes and (ii) future map definitions. Therefore, the first robust VSB data packet of the frame for the outcoder has the structure shown in Fig. 17, and the robust VSB map definition data is given as follows. That is, they represent 8 bits representing the current map (only 6 of these bits are used), 8 bits representing the number of frames until the map is changed (if there is 1 to 125: 0, then no changes are made) 8 bits representing the next map (again, only 6 of these bits are used). The remaining portion of the first robust VSB data packet is data. The first RVSB segment in the frame for each outer coder has the arrangement shown in Fig.

In this way, the receiver can track the map changes using reliable robust VSB data. Even if the burst error destroys the number of frames, the receiver can keep its own frame using the number of frames already read from the received frame. If the receiver finds at any time that the definition for the outer code previously obtained by the frame synchronous correlation does not match the definition for the outer code in the first robust VSB data segment, the receiver must resume its map acquisition process do.

RVSB Extended Slice Prediction and Equalizer Feedback

The ATSC 8VSB receiver is described in the ATSC Digital Television Specification A / 53 issued by The Advanced Television Systems Committee and also in the instructions for use of the ATSC Digital Television Specification A / 54 issued by Advance Television Systems Comiti As well as adaptive equalization and phase tracking. The RVSB as described above has features that allow for improvements in adaptive equalization and phase tracking.

One such improvement is caused by feedback of delayed reliable evaluation of the input symbol level to the adaptive equalizer and / or phase tracker based on sequence evaluation from the extended Viterbi algorithm (" The Viterbi Algorithm " GD Forney, Tr , Proc. IEEE, Vol. 61, pp. 268-278, March, 1973). This type of feedback avoids the need for re-encoding with initialization initialization problems.

In the " slice predictor for a signal receiver " No. 5,923,711 discloses an ATSC 8VSB receiver that uses a slice predictor to provide more reliable feedback with a phase tracker or adaptive equalizer. Such feedback can be made more reliable by the extended slice predictor system 300 shown in FIG. The extended slice predictor system 300 has an inner decoder 302 and an outer decoder 304 that operate similarly to the inner decoder and the outer decoder described above.

The slice prediction output from the inner decoder 302 operates in a similar manner as disclosed in the above-mentioned U.S. Patent No. 5,923,711. As described above, the inner decoder 302 is based on an 8-state 4-ary trellis including a precoder. Based on the best path metric at the current time t, the slice predictor of the inner decoder 302 determines the most desirable state at time t. Based on the possible state of the next pair, four possible predicted input levels (8 outputs) for the next symbol are selected at time t + 1. For example, as shown by the inner decoder trellis in FIG. 20, if the most desirable state at time t is state 1, the next state is E [1526]. Thus, the next input level at time t + 1 may be -8, +1, -3, or +5. These next input levels correspond to bit pairs 00, 10, 01 and 11, respectively, to be decoded.

Likewise, the outer decoder 304 also looks for the optimal path metric for the current time t for each trellis. A portion of this trellis is shown in FIG. 21 for an exemplary outer decoder and is generally applicable to all three outer codes. As shown in FIG. 21, the two possible outer decoder input bit pairs are then selected for time t + 1 based on a pair of possible states. According to one example method, the two possible pairs of outer decoder input bits may be 11 or 01. The bit pair selected by the outer coder 304 is a prediction that selects amplitude level -5 or -3 from the four level set preselected by the slice predictor of the inner decoder 302 as extended slice prediction for time t + And is sent to the expander 306. Since the slice prediction of the inner decoder 302 is a delay of n zeros but the outer decoder 304 can not operate with the same symbol until after the inner decoder 302 provides the coded soft output, Provides a slightly longer delay time than the tracking delay time of the inner decoder 302. [ The slice prediction provided by the prediction extender 306 may be supplied as feedback to the equalizer of the phase tracker 310. [

The outer decoder 304 may make a final hard decision to have a little additional delay time to select a single most desirable input bit pair for time t + l. For example, if 11 is found to be the most desirable input bit pair to the outer decoder 304 as determined by the Viterbi algorithm, then such information is already stored by the 4-level set and the slice predictor of the inner decoder 302 Is sent by the outer decoder 304 to a prediction extender 306 that selects +5 from the selected corresponding bit pair. The outer decoder may be a convolutional code or other type of error correction code. The prediction extender 306 is disabled while the ATSC data is being received.

The maximal likelihood sequence estimator (MLSE) slice predictor system 320 of the feedback extension uses the Viterbi algorithm and is shown in FIG. 22 as in other related parts of the RVSB receiver. The MLSE slice predictor system 320 of the feedback extension has an inner decoder 322 and an outer decoder 302 that operate similarly to the inner decoder 302 and the outer decoder 304 described above.

However, instead of using the slice prediction output of the inner decoder 302, the extended MLSE module 326 may use the 8 state 213 rate code trellis (the same trellis used by the inner decoder 322 including the precoder) So as to perform a normal Viterbi algorithm on the received signal.

The extended MLSE module 326 may then receive as input a noise 8 level received signal as delayed by the delay module 328 if the input is then a non-RVSB symbol or (ii) if the next input is an RVSB symbol, (Hard or soft) of the bit-pair determination output of the selector 324. The extended MLSE module 326 makes this selection according to the symbol by symbol information in the RVSB map.

The extended MLSE module 326 outputs one of the eight possible symbols on its slice side and this slice prediction is provided by the MLSE module 326 incremented by feedback to the equalizer or phase tracker 330 do.

Because the extended MLSE module 326 can obtain a more reliable input from the outer decoder 324 when the RVSB symbol is available, the extended MLSE module 326 is able to receive the more reliable input from the outer decoder 324 through the 8 state trellis You should follow a more correct path.

The output of the extended MLSE module 326 may be a hard slice decision or soft level. An indication of any symbol reliability from the inner decoder 322 or the outer decoder 324 may also be used to change the step size of the equalizer CMS algorithm (see the ATSC Digital Television Specification A / 54 Usage Guide). An optional pre-set encoding training sequence may be included within a particular portion of the first RVSB segment of the data field. This sequence is known in advance by both the transmitter and the receiver. During the time that the decoded training sequence is output from the outer decoder 324, the input to the extended MLSE module 326 is switched to the stored version of the decoded training sequence.

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 spirit and scope of the invention as defined by the appended claims. For example, although the standard ATSC receiver 12 and the robust VSB receiver 14 have been described above as separate receivers, the functionality of these two sub-ATSC receivers 12 and robust VSB receivers 14 is of two types Can be combined into two data paths of a single receiver capable of decoding data (ATSC data and robust VSB data).

Accordingly, the description of the invention should be construed as illustrative only, and the best mode of carrying out the invention is to be learned by those skilled in the art.

Substantial details may be changed without departing from the spirit of the invention, and the exclusive use of all modifications within the scope of the appended claims is intended to be embraced therein.

Included in the above.

Claims (23)

Level data having first and second N-level data having the same arrangement and different bit rates as the map including information indicating the position of at least one of the first and second N-level data in the data frame, Receiving a signal; And And processing the first and second N-level data according to the map. The method according to claim 1, Wherein the received digital signal comprises a replica of the map. 3. The method of claim 2, Characterized in that the data frame comprises an ATSC frame having a frame sync segment and a plurality of data segments, the map being contained in the frame sync segment and the duplication of the map being included in one of the data segments. Receiving and processing method. The method according to claim 1, 2, or 3, Wherein the received digital signal further comprises data indicating when the map will change in the future. The method according to claim 1, 2, or 3, Wherein the received digital signal further comprises a new map to be transmitted in the future. 6. The method of claim 5, Wherein the received digital signal further comprises data indicating when a new map is to be transmitted in the future. The method according to claim 1, Wherein the map includes information indicating a coding rate of the first and second N-level data, and the processing step comprises decoding the first and second N-level data based on the different coding rates indicated by the map Wherein the digital signal is received and processed. The method according to claim 1, Wherein the first N level data comprises first robust 8 VSB data and the second N level data comprises second robust 8 VSB data. The method according to claim 1, Wherein the first N-level data comprises robust 8 VSB data and the second N-level data comprises ATSC data. The method according to claim 1, Further comprising correlating multiple transmissions of the map. ≪ RTI ID = 0.0 > 11. < / RTI > The method according to claim 1, Wherein the digital signal further comprises third N-level data, wherein the map is generated such that the first N-level data is outcoded at a first coding rate, the second N-level data is outcoded at a second coding rate, Level data is outcoded at a third coding rate, the map comprising first, second and third portions, wherein the first portion comprises a first N-level data The second portion indicates that second level data can be found in a portion of the data frame and the third portion indicates that third level data can be found in which portion of the data frame Receiving and processing a digital signal. 12. The method of claim 11, The map has 54 symbols, the first portion has the 18th symbol out of 54 symbols, the second portion has the second other 18 symbols out of 54 symbols, the third portion has 54 symbols out of 54 symbols, And further comprises 18 symbols. ≪ RTI ID = 0.0 > 18. < / RTI > 13. The method of claim 12, The first, second and third 18 symbols each comprise 6 symbols designated as G supporting which first, second and third N-level data in the data frame can be found; Six symbols designating the complement of G; And Characterized in that it comprises six sub-specific symbols. 14. The method of claim 13, Characterized in that the data frame comprises an ATSC frame with a frame sync segment, the frame sync segment comprises 12 pre-coding symbols, and the map is included in a frame sync segment of an ATSC frame immediately before the 12 pre- Receiving and processing a digital signal. 12. The method of claim 11, The first, second, A first symbol designated as G indicating which portion of the data frame corresponding first, second and third N-level data can be found; A second symbol indicating a repair of G; And And a third part specific symbol. 12. The method of claim 11, Wherein the data frame comprises m data segments and wherein the first portion of the map comprises a first number of zeros to n indicating a first subset of m data segments comprising all of the first N level data, And the second portion of the map has a second number from zero to n indicating a second subset of the m data segments including all of the second N level data, And a third number from zero to n indicating a third subset of m data segments comprising all of the N-level data, wherein the first number plus second number plus third number is less than or equal to n, m. < / RTI > The method according to claim 1, Further comprising the step of: maintaining a counter as to when the map is to be changed. The method according to claim 1, Wherein the data frame comprises m data segments and the map specifies a plurality of predefined data segments, wherein all of the first N level data is contained within the predefined segment. 19. The method of claim 18, Wherein the map includes numbers from zero to n, and n is evenly divided into m. 20. The method of claim 19, Wherein n is 39. The method of claim 1, 21. The method of claim 20, Wherein the m data segment includes only the first N level data if the map includes the number 39. < Desc / Clms Page number 13 > The method according to claim 1, Wherein the processing step comprises discarding the first N-level data based on the PID number. The method according to claim 1, Wherein the processing step includes discarding the first N-level data based on the PID number, And discarding the second N-level data based on the map.