Abstract: In order to reduce the gap between the TPC (Turbo Product Code) and Shannon’s limit performance,
we generalized the Non-sequential decoding algorithm for SISO (Soft-Input/ Soft-Output) decoding of TPC. The
proposed algorithm only decodes the reliable component codes to avoid introducing extra errors. The simulation
results show that the error rate of the NS-SISO decoding algorithm is only half of the standard SISO algorithm
when Hamming code (64,57,4) is used as component code of TPC. It can be seen that the new algorithm has a
visible error performance gain.

Key words:  turbo product codes(TPC), non-sequential decodes, iterative decodes, channel coding