System for digital television broadcasting using modified 2/3 trellis coding

Abstract

Serially concatenated convolutional coding (SCCC) transmitting ancillary data within DTV signals incorporates the ⅔ trellis coding used for all DTV signals as its inner convolutional coding. The outer convolutional coding of the SCCC is subjected to _“anti-Gray”_ coding, either before or after its interleaving, but before its inner convolutional coding. In a receiver for ancillary data as so transmitted, simple logic circuitry recodes portions of the trellis decoded DTV signal containing soft decisions as to the symbol-interleaved convolutionally coded ancillary data to provide a Gray-code mapping of symbols to modulation levels. This recoding is done either before or after symbol de-interleaving, but before decoding the outer convolutional coding to recover ancillary data. Soft decisions concerning extrinsic information to be fed back to the ⅔ trellis decoder to close a turbo decoding loop are derived from soft decisions as to the ancillary data, and this derivation includes recoding for a binary-code mapping of symbols to modulation levels.

1 . (canceled) 
   
   
       2 . A receiver for vestigial-sideband amplitude-modulation (VSB AM) signal, successive symbols of the modulating signal for said VSB AM signal defining a digital signal in accordance with an eight-level symbol alphabet superposed on a pedestal, said digital signal composed of successive frames each composed of two respective fields of digital-signal symbols, each said field composed of a respective initial segment of 832 digital-signal symbols succeeded by respective 312 consecutive further segments of 832 digital-signal symbols apiece, the four initial digital-signal symbols of each of said segments of 832 digital-signal symbols being a prescribed data segment synchronizing signal sequence, the final 828 digital-signal symbols of said 312 further segments of each said field of digital-signal symbols having prescribed ⅔ trellis coding, three-bit symbols of said ⅔ trellis coding being mapped to said eight-level symbol alphabet in such manner as to generate binary-coded modulation superposed on said pedestal, at least some said respective 312 further segments of said fields of digital-signal symbols including within selected portions thereof digital-signal symbols generated by said prescribed ⅔ trellis coding responding to M/H service data that has been randomized and encoded with an outer coding, two-bit symbols of which outer coding are subjected to symbol interleaving and anti-Gray-coding before being ⅔ trellis coded, said receiver comprising:
 apparatus for receiving a selected vestigial-sideband amplitude-modulation signal and converting it to a baseband digital signal including successive reproduced eight-level symbols of 12-phase ⅔ trellis-coded baseband digital signal;   an inner soft-input/soft-output (SISO) decoder connected for trellis decoding said successive reproduced eight-level symbols of 12-phase ⅔ trellis-coded baseband digital signal to generate an inner decoder response composed of soft decisions concerning two-bit symbols previously encoded within said eight-level symbols, each soft decision composed of a-respective hard decision as to the value of each of said two-bit symbols and an accompanying indication of the probability of that said respective two-bit symbol being correct;   a first soft-decision recoder of the kind set forth in  claim 37 , connected for recoding ones of said soft decisions generated by said inner SISO decoder that concern anti-Gray-coded two-bit symbols of symbol-interleaved M/H service data encoded with said outer coding, thus to generate soft decisions regarding two-bit symbols of symbol-interleaved M/H service data encoded with said outer coding; and   a symbol de-interleaver connected for receiving said soft decisions regarding two-bit symbols of symbol-interleaved M/H service data encoded with said outer coding and complementing said symbol interleaving to generate de-interleaved M/H service data encoded with said outer coding; and   an outer soft-input/soft-output (SISO) decoder for said M/H service data encoded with an outer coding connected for receiving said de-interleaved M/H service data encoded with said outer coding from said symbol de-interleaver and further decoding said de-interleaved M/H service data to generate soft decisions concerning bits of said M/H service data and accompanying bits from said outer coding.   
   
   
       3 . The  claim 2  receiver, further comprising:
 a symbol interleaver connected for receiving said soft decisions concerning bits of said M/H service data and accompanying bits from said outer coding from said outer SISO decoder and symbol-interleaving successive ones of them to generate symbol-interleaved soft decisions of a symbol-interleaved turbo feedback signal;   a second soft-decision recoder of the kind set forth in  claim 37 , connected for recoding said symbol-interleaved soft decisions in said symbol-interleaved turbo feedback signal to generate symbol-interleaved soft decisions of an anti-Gray-coded symbol-interleaved turbo feedback signal; and   a comparator for determining anti-Gray-coded extrinsic information to modify operation of said inner soft-input/soft-output decoder, said comparator being connected to determine said anti-Gray-coded extrinsic information by comparing said anti-Gray-coded symbol-interleaved turbo feedback signal with said inner SISO decoder response.   
   
   
       4 . The  claim 3  receiver, further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions concerning bits of said M/H service data, which said soft decisions are generated by said outer SISO decoder;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       5 . The  claim 3  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions concerning bits of said M/H service data, which said soft decisions are generated by said outer SISO decoder;   a bit interleaver for interleaving said successive hard decisions in accordance with a bit-interleaving pattern complementary to said bit de-interleaving pattern, thereby generating successive bit-interleaved hard decisions;   an M/H Frame decoder connected for receiving as an input signal thereto said successive bit-interleaved hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       6 . The  claim 3  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said symbol-interleaved soft decisions generated by said symbol interleaver;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       7 . The  claim 2  receiver, further comprising:
 a second soft-decision recoder of the kind set forth in  claim 37 , connected for generating soft decisions concerning an anti-Gray-coded turbo feedback signal by recoding said soft decisions generated by said outer SISO decoder;   a symbol interleaver connected for receiving said soft decisions concerning said anti-Gray-coded turbo feedback signal and symbol-interleaving successive ones of them to generate symbol-interleaved soft decisions in a symbol-interleaved anti-Gray-coded turbo feedback signal; and   a comparator for determining anti-Gray-coded extrinsic information to modify operation of said inner SISO decoder, said comparator being connected to determine said anti-Gray-coded extrinsic information by comparing said symbol-interleaved anti-Gray-coded turbo feedback signal with said inner decoder response.   
   
   
       8 . The  claim 7  receiver, further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       9 . The  claim 7  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   a bit interleaver for interleaving said successive hard decisions in accordance with a bit-interleaving pattern complementary to said bit de-interleaving pattern, thereby generating successive bit-interleaved hard decisions;   an M/H Frame decoder connected for receiving as an input signal thereto said successive bit-interleaved hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       10 . The  claim 2  receiver, further comprising:
 a symbol interleaver connected for receiving said soft decisions generated by said outer SISO decoder and symbol-interleaving successive ones of them to generate successive symbol-interleaved soft decisions within a symbol-interleaved turbo feedback signal;   a comparator for determining extrinsic information by comparing soft decisions in said symbol-interleaved turbo feedback signal with said soft decisions regarding two-bit symbols of symbol-interleaved M/H service data encoded with said outer coding as supplied to said symbol de-interleaver; and   a second soft-decision recoder of the kind set forth in  claim 37 , connected for recoding two-bit symbols of said extrinsic information to generate anti-Gray-coded extrinsic information supplied to said inner SISO decoder to modify its operation.   
   
   
       11 . The  claim 10  receiver, further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       12 . The  claim 10  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   a bit interleaver for interleaving said successive hard decisions in accordance with a bit-interleaving pattern complementary to said bit de-interleaving pattern, thereby generating successive bit-interleaved hard decisions;   an M/H Frame decoder connected for receiving as an input signal thereto said successive bit-interleaved hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       13 . The  claim 10  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said symbol-interleaved soft decisions generated by said symbol interleaver;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       14 . The  claim 2  receiver, further comprising:
 a comparator for determining de-interleaved extrinsic information, said comparator being connected to determine said de-interleaved extrinsic information by comparing soft decisions regarding M/H service data encoded with said outer coding as supplied from said symbol de-interleaver with said soft decisions generated by said outer SISO decoder;   a symbol interleaver connected for receiving said de-interleaved extrinsic information as determined by said comparator and symbol-interleaving successive two-soft-bit symbols of said de-interleaved extrinsic information to generate successive two-soft-bit symbols of symbol-interleaved extrinsic information; and   a second soft-decision recoder of the kind set forth in  claim 37 , connected for being addressed by at least successive two-soft-bit data symbol portions of said symbol-interleaved extrinsic information, said second soft-decision recoder anti-Gray coding said successive two-soft-bit symbols of said symbol-interleaved extrinsic information to generate successive two-soft-bit symbols of anti-Gray-coded extrinsic information supplied to said inner SISO decoder to modify its operation.   
   
   
       15 . The  claim 14  receiver, further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       16 . The  claim 14  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said MI/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   a bit interleaver for interleaving said successive hard decisions in accordance with a bit-interleaving pattern complementary to said bit de-interleaving pattern, thereby generating successive bit-interleaved hard decisions;   an M/H Frame decoder connected for receiving as an input signal thereto said successive bit-interleaved hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       17 . The  claim 2  receiver, further comprising:
 a comparator for determining de-interleaved extrinsic information, said comparator being connected to determine two-soft-bit symbols of said de-interleaved extrinsic information by comparing soft decisions regarding two-bit symbols of M/H service data encoded with said outer coding as supplied from said symbol de-interleaver with said soft decisions regarding two-bit symbols of M/H service data encoded with said outer coding as supplied from said outer SISO decoder;   a second soft-decision recoder of the kind set forth in  claim 37 , connected for being addressed by two-soft-bit symbols of said de-interleaved extrinsic information, said second read-only memory anti-Gray coding each respective two-soft-bit symbol of said de-interleaved extrinsic information to generate a respective two-soft-bit symbol of anti-Gray-coded de-interleaved extrinsic information; and   a symbol interleaver connected for receiving successive said two-soft-bit symbols of anti-Gray-coded de-interleaved extrinsic information and symbol-interleaving successive ones of them to generate two-soft-bit symbols of symbol-interleaved anti-Gray-coded extrinsic information supplied to said inner SISO decoder to modify its operation.   
   
   
       18 . The  claim 17  receiver, further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       19 . The  claim 17  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   a bit interleaver for interleaving said successive hard decisions in accordance with a bit-interleaving pattern complementary to said bit de-interleaving pattern, thereby generating successive bit-interleaved hard decisions;   an M/H Frame decoder connected for receiving as an input signal thereto said successive bit-interleaved hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       20 . A receiver for vestigial-sideband amplitude-modulation (VSB AM) signal, successive symbols of the modulating signal for said VSB AM signal defining a digital signal in accordance with an eight-level symbol alphabet superposed on a pedestal, said digital signal composed of successive frames each composed of two respective fields of digital-signal symbols, each said field composed of a respective initial segment of 832 digital-signal symbols succeeded by respective 312 consecutive further segments of 832 digital-signal symbols apiece, the four initial digital-signal symbols of each of said segments of 832 digital-signal symbols being a prescribed data segment synchronizing signal sequence, the final 828 digital-signal symbols of said 312 further segments of each said field of digital-signal symbols having prescribed ⅔ trellis coding, three-bit symbols of said ⅔ trellis coding being mapped to said eight-level symbol alphabet in such manner as to generate binary-coded modulation superposed on said pedestal, at least some said respective 312 further segments of said fields of digital-signal symbols including within selected portions thereof digital-signal symbols generated by said prescribed ⅔ trellis coding responding to M/H service data that has been randomized and encoded with an outer coding, two-bit symbols of which outer coding are subjected to symbol interleaving and anti-Gray-coding before being ⅔ trellis coded, said receiver comprising:
 apparatus for receiving a selected vestigial-sideband amplitude-modulation signal and converting it to a baseband digital signal including successive reproduced eight-level symbols of 12-phase ⅔ trellis-coded baseband digital signal, an inner soft-input/soft-output (SISO) decoder connected for trellis decoding said successive reproduced eight-level symbols of 12-phase ⅔ trellis-coded baseband digital signal to generate an inner decoder response composed of soft decisions concerning two-bit symbols previously encoded within said eight-level symbols, each soft decision composed of a respective hard decision as to the value of each of said two-bit symbols and an accompanying indication of the probability of that said respective two-bit symbol being correct;   a symbol de-interleaver connected for receiving said soft decisions generated by said inner SISO decoder and complementing said symbol interleaving to supply de-interleaved soft decisions;   a first soft-decision recoder of the kind set forth in  claim 37 , connected for recoding said de-interleaved soft decisions supplied from said symbol de-interleaver to generate recoded de-interleaved soft decisions; and   an outer soft-input/soft-output (SISO) decoder for said M/H service data encoded with an outer coding connected for receiving said recoded de-interleaved soft decisions and further decoding said recoded de-interleaved soft decisions as so received to generate soft decisions concerning said bits of said M/H service data and accompanying bits from said outer coding.   
   
   
       21 . The  claim 20  receiver, further comprising:
 a symbol interleaver connected for receiving said soft decisions concerning two-bit symbols of said M/H service data from said outer SISO decoder and symbol-interleaving successive ones of them to generate symbol-interleaved soft decisions of a symbol-interleaved turbo feedback signal;   a second soft-decision recoder of the kind set forth in  claim 37 , connected for recoding said symbol-interleaved soft decisions in said symbol-interleaved turbo feedback signal to generate symbol-interleaved soft decisions of an anti-Gray-coded symbol-interleaved turbo feedback signal; and   a comparator for determining anti-Gray-coded extrinsic information to modify operation of said inner soft-input/soft-output decoder, said comparator being connected to determine said anti-Gray-coded extrinsic information by comparing said anti-Gray-coded symbol-interleaved turbo feedback signal with said inner SISO decoder response.   
   
   
       22 . The  claim 21  receiver, further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       23 . The  claim 21  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   a bit interleaver for interleaving said successive hard decisions in accordance with a bit-interleaving pattern complementary to said bit de-interleaving pattern, thereby generating successive bit-interleaved hard decisions;   an M/H Frame decoder connected for receiving as an input signal thereto said successive bit-interleaved hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       24 . The  claim 21  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said symbol-interleaved soft decisions generated by said symbol interleaver;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       25 . The  claim 20  receiver, further comprising:
 a second soft-decision recoder of the kind set forth in  claim 37 , connected for generating soft decisions concerning two-bit symbols of an anti-Gray-coded turbo feedback signal by recoding said soft decisions generated by said outer SISO decoder;   a symbol interleaver connected for receiving said soft decisions concerning two-bit symbols of said anti-Gray-coded turbo feedback signal and symbol-interleaving successive ones of them to generate symbol-interleaved soft decisions in a symbol-interleaved anti-Gray-coded turbo feedback signal; and   a comparator for determining anti-Gray-coded extrinsic information to modify operation of said inner SISO decoder, said comparator being connected to determine said anti-Gray-coded extrinsic information by comparing said symbol-interleaved anti-Gray-coded turbo feedback signal with said inner decoder response.   
   
   
       26 . The  claim 25  receiver, further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       27 . The  claim 25  receiver as adapted for receiving MI/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   a bit interleaver for interleaving said successive hard decisions in accordance with a bit-interleaving pattern complementary to said bit de-interleaving pattern, thereby generating successive bit-interleaved hard decisions;   an M/H Frame decoder connected for receiving as an input signal thereto said successive bit-interleaved hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       28 . The  claim 20  receiver, further comprising:
 a second soft-decision recoder of the kind set forth in  claim 37 , connected for generating soft decisions concerning an anti-Gray-coded turbo feedback signal by recoding said soft decisions generated by said outer SISO decoder;   a comparator for determining de-interleaved anti-Gray-coded extrinsic information, said comparator being connected to determine successive two-soft-bit symbols of said de-interleaved anti-Gray-coded extrinsic information by comparing successive two-soft-bit symbols of said anti-Gray-coded turbo feedback signal with two-soft-bit symbols of M/H service data encoded with said outer coding as supplied from said symbol de-interleaver; and   a symbol interleaver connected for receiving successive said successive two-soft-bit symbols of said de-interleaved anti-Gray-coded extrinsic information from said comparator and symbol-interleaving them to generate successive two-soft-bit symbols of symbol-interleaved anti-Gray-coded extrinsic information supplied to said inner SISO decoder to modify its operation.   
   
   
       29 . The  claim 28  receiver, further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       30 . The  claim 28  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   a bit interleaver for interleaving said successive hard decisions in accordance with a bit-interleaving pattern complementary to said bit de-interleaving pattern, thereby generating successive bit-interleaved hard decisions;   an M/H Frame decoder connected for receiving as an input signal thereto said successive bit-interleaved hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       31 . The  claim 20  receiver, further comprising:
 a comparator for determining de-interleaved extrinsic information, said comparator being connected to determine said de-interleaved extrinsic information by comparing soft decisions supplied from said symbol de-interleaver with said soft decisions generated by said outer SISO decoder;   a symbol interleaver connected for receiving said de-interleaved extrinsic information as determined by said comparator and symbol-interleaving successive two-soft-bit symbols of said de-interleaved extrinsic information to generate successive two-soft-bit symbols of symbol-interleaved extrinsic information; and   a second soft-decision recoder of the kind set forth in  claim 37 , connected for being addressed by at least successive two-soft-bit data symbol portions of said symbol-interleaved extrinsic information, said second soft-decision recoder anti-Gray coding said successive two-soft-bit symbols of said symbol-interleaved extrinsic information to generate successive two-soft-bit symbols of anti-Gray-coded extrinsic information supplied to said inner SISO decoder to modify its operation.   
   
   
       32 . The  claim 31  receiver, further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       33 . The  claim 31  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   a bit interleaver for interleaving said successive hard decisions in accordance with a bit-interleaving pattern complementary to said bit de-interleaving pattern, thereby generating successive bit-interleaved hard decisions;   an M/H Frame decoder connected for receiving as an input signal thereto said successive bit-interleaved hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       34 . The  claim 20  receiver, further comprising:
 a comparator for determining de-interleaved extrinsic information, said comparator being connected to determine two-soft-bit symbols of said de-interleaved extrinsic information by comparing soft decisions regarding two-bit symbols of M/H service data encoded with said outer coding as supplied from said symbol de-interleaver with said soft decisions regarding two-bit symbols of M/H service data encoded with said outer coding as supplied from said outer SISO decoder;   a second soft-decision recoder of the kind set forth in  claim 37 , connected for being addressed by two-soft-bit symbols of said de-interleaved extrinsic information, said second read-only memory anti-Gray coding each respective two-soft-bit symbol of said de-interleaved extrinsic information to generate a respective two-soft-bit symbol of anti-Gray-coded de-interleaved extrinsic information; and   a symbol interleaver connected for receiving successive said two-bit symbols of anti-Gray-coded de-interleaved extrinsic information and symbol-interleaving successive ones of them to generate symbol-interleaved anti-Gray-coded extrinsic information supplied to said inner SISO decoder to modify its operation.   
   
   
       35 . The  claim 34  receiver, further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   an M/H Frame decoder connected for receiving as an input signal thereto said successive hard decisions as to bits of said M/H service data and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said M/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       36 . The  claim 34  receiver as adapted for receiving M/H service data that has been bit de-interleaved in accordance with a prescribed bit de-interleaving pattern after having been randomized but before having been encoded with said outer coding and subjected to symbol interleaving, said receiver further comprising:
 a hard-decision unit connected for generating successive hard decisions as to bits of said M/H service data responsive to portions of said soft decisions generated by said outer SISO decoder;   a bit interleaver for interleaving said successive hard decisions in accordance with a bit-interleaving pattern complementary to said bit de-interleaving pattern, thereby generating successive bit-interleaved hard decisions;   an M/H Frame decoder connected for receiving as an input signal thereto said successive bit-interleaved hard decisions and for responding to supply data-randomized transport stream packets; and   a data de-randomizer connected for receiving data-randomized transport stream packets supplied from said Mi/H Frame decoder and de-randomizing them to supply restored transport stream packets.   
   
   
       37 . A soft-decision recoder for recoding a first succession of soft decisions each composed of a respective pair of soft bits to generate a second succession of soft decisions each composed of a respective pair of soft bits, each of said soft bits consisting of first through nth bits, the first of each of said soft bits consisting of a respective hard bit and the second through nth of each of said soft bits indicative of the likelihood of its said respective hard bit being correct, said soft-decision recoder comprising:
 a plurality n in number of logic gates, each of said logic gates connected to receive as a respective first input signal thereto said respective hard bits of first ones of each of said pairs of soft bits in said first succession of soft decisions, the first through nth ones of said logic gates connected to receive as respective input signals thereto respective ones of the first through nth bits of second ones of each of said pairs of soft bits in said first succession of soft decisions; wherein the first through nth bits of first ones of each of said pairs of soft bits in said second succession of soft decisions are derived from the first through nth bits of first ones of each of said pairs of soft bits in said first succession of soft decisions; and wherein the first through nth bits of second ones of each of said pairs of soft bits in said second succession of soft decisions are derived from the responses of the first through nth ones of said logic gates respectively.   
   
   
       38 . The  claim 37  soft-decision recoder, wherein each of said logic gates n in number is a respective exclusive-OR gate, wherein the first through nth bits of first ones of each of said pairs of soft bits in said second succession of soft decisions correspond to the first through nth bits of first ones of each of said pairs of soft bits in said first succession of soft decisions, and wherein the first through nth bits of second ones of each of said pairs of soft bits in said second succession of soft decisions correspond to the responses of the first through nth ones of said logic gates respectively. 
   
   
       39 . The  claim 37  soft-decision recoder, wherein each of said logic gates n in number is a respective exclusive-NOR gate, wherein the first through nth bits of first ones of each of said pairs of soft bits in said second succession of soft decisions correspond to the first through nth bits of first ones of each of said pairs of soft bits in said first succession of soft decisions, and wherein the first through nth bits of second ones of each of said pairs of soft bits in said second succession of soft decisions correspond to the responses of the first through nth ones of said logic gates respectively.