Cyclic redundancy check based message passing in turbo product code decoding

A communication system, comprising:

• iterative decoder implementing circuitry configured to:
• i) receive an interleaved turbo product code (TPC) code word at a sequence detector;
• ii) perform a soft decision algorithm to the interleaved TPC code word at the sequence detector;
• iii) transmit the interleaved TPC code word to a TPC decoder, the transmission adapted to de-interleave the TPC code word;
• iv) decode the de-interleaved TPC code word at the TPC decoder into a plurality of code blocks;
• v) perform a cyclic redundancy check (CRC) on each of the plurality of code blocks of the TPC code word;
• vi) assign an artificially high probability confidence measure to bits of any of the plurality of code blocks which pass the CRC;
• and
• vii) iteratively decode the TPC code word between the soft decision algorithm of the sequence detector and the TPC decoder using the artificially high probability confidence measure assigned to bits of code blocks which pass the CRC, the TPC code word re-interleaved when transmitted to the sequence detector.

An apparatus comprising:

• an iterative decoder having a TPC decoder and a sequence detector implementing a soft decision algorithm, the iterative decoder configured to iteratively decode a turbo product code (TPC) code word between the sequence detector and TPC decoder, the TPC code word interleaved at the sequence detector and de-interleaved at the TPC decoder;
• cyclic redundancy check (CRC) implementing circuitry configured to perform a CRC on each of a plurality of code blocks of the TPC code word;
• and
• pre-determined extrinsic information generating circuitry configured to assign extrinsic information representing an artificially high probability confidence measure to bits of any of the plurality of code blocks which pass the CRC, the artificially high probability confidence measure used by the iterative decoder.

An iterative decoder, comprising:

• a sequence detector adapted to receive an interleaved turbo product code (TPC) code word and to perform a soft decision algorithm to the interleaved TPC code word;
• a de-interleaver adapted to de-interleave and transmit the TPC code word from the sequence detector;
• a TPC decoder adapted to receive the de-inteleaved TPC code word and to decode the de-interleaved TPC code word into a plurality of code blocks;
• cyclic redundancy check (CRC) circuitry adapted to perform a CRC on each of the plurality of code blocks of the TPC code word from the TPC decoder and to assign an artificially high probability confidence measure to bits of any of the plurality of code blocks which pass the CRC before returning the TPC code word to the TPC decoder;
• and
• an interleaver adapted to interleave and transmit the TPC code word from the TPC decoder to the sequence detector, wherein the TPC code word is iteratively decoded between the soft decision algorithm of the sequence detector and the TPC decoder using the artificially high probability confidence measure assigned to bits of code blocks which pass the CRC.

A method, comprising:

• performing a cyclic redundancy check (CRC) on each of a plurality of code blocks of a turbo product code (TPC) code word;
• assigning an artificially high probability confidence measure to bits of any of the plurality of code blocks which pass the CRC;
• and
• iteratively decoding the TPC code word between a soft decision algorithm of a sequence detector and a TPC decoder using the artificially high probability confidence measure assigned to bits of code blocks which pass the CRC, the TPC code word interleaved at the sequence detector and de-interleaved at the TPC decoder.