Reduced-complexity check node processing for non-binary LDPC decoding

Non-binary low-density parity-check (NB-LDPC) codes can achieve better error-correcting performance than their binary counterparts when the code length is moderate. Check node processing is one bottleneck in NB-LDPC decoding. Various techniques have been proposed to simplify the check node processing. Particularly, the computation complexity can be reduced by employing an iterative forward-backward scheme. However, this scheme requires large memory to store intermediate results. In this paper, a novel check node processing scheme and corresponding VLSI architectures are proposed for the Min-max NB-LDPC decoding. The proposed scheme first chooses a limited number of variable-to-check messages, then the check-to-variable messages to all connected variable nodes are generated independently. Employing the proposed architecture, the area requirement of the check node processing for an (837, 726) NB-LDPC code over GF (2⁵) can be reduced to 22.5% of that of the previous work with the same processing speed and error-correcting performance.