METHOD OF ENCODING-DECODING MULTISTAGE CODE STRUCTURE IN DATA TRANSMISSION SYSTEMS Russian patent published in 2011 - IPC H03M13/00 

FIELD: information technology.

SUBSTANCE: at the transmitting side, cyclic redundancy check (CRC) is added to the initial information and the obtained block is encoded by an external code in the GF(q) field and an internal code. At the receiving side, the information block is decoded by an internal code. Sequences of the decoded code words, uncorrectable code words and deleted code words are recorded. Further, an array of decoded code words of the internal code is decoded by an external code and the CRC is calculated and checked. In case of positive result, the information is sent to a message recipient; otherwise the sequence of deleted code words is restored: contenders for restoration are calculated, while inverting each bit in each uncorrectable code word, code words with inverted bits are decoded by an internal code, the obtained code combination is checked for coincidence with code combinations obtained earlier. If such a code combination has not existed before, the deleted code words are replaced with decoded words, the obtained array of decoded code words is decoded once more with an external code and the CRC is recalculated and re-checked until a positive result is obtained.

EFFECT: possibility of using various code structures in a data transmission system and adaptive alteration thereof depending on the signal-noise environment, cutting on the required amount of memory.