Low-complexity architectures for reliability-based message-passing non-binary LDPC decoding

When the code is not long, non-binary low-density parity- check (NB-LDPC) codes can achieve better error-correcting performance than binary LDPC codes at the cost of higher decoding complexity. The recently developed iterative reliability-based majority-logic NB- LDPC decoding can achieve better performance-complexity tradeoffs than previous algorithms. Many existing NB-LDPC code construction schemes lead to quasi-cyclic or cyclic codes. In this paper, efficient low- complexity NB-LDPC decoder architectures are developed for these two types of codes based on the newly proposed iterative hard reliability-based majority-logic decoding (IHRB-MLGD). Particularly, novel schemes are designed to keep a small proportion of messages in order to reduce the memory requirement without causing noticeable performance loss. Moreover, a shift-message structure is proposed by using memories concatenated with variable node units to enable efficient partial-parallel decoding for cyclic NB-LDPC codes. Compared to previous decoders based on the Min-max algorithm, the proposed IHRB-MLGD decoder architectures can achieve tens of times higher efficiency for codes with similar length and rate with moderate coding gain loss.