Efficient symbol reliability based decoding for QCNB-LDPC codes

As an extension of binary low-density parity-check (LDPC) codes, non-binary LDPC (NB-LDPC) codes show significantly better performance when the code length is moderate or small. Recently, enhanced iterative hard reliability based (EIHRB) decoding algorithm is proposed to reduce the computation complexity. However, the EIHRB algorithm suffers a lot from significant performance degradation when the column weight is small. In this paper, a symbol reliability based (SRB) decoding algorithm, which also performs well when the column weight is low, is proposed for NB-LDPC decoding to improve the decoding performance. With the same maximum iteration number, around 0.38 dB extra coding gain is achieved. Furthermore, the corresponding efficient decoder architecture is proposed. Comparison results have shown that the proposed SRB algorithm can not only achieve good coding gain, but the cost for hardware implementation is reasonable.