Low latency check node unit architecture for nonbinary LDPC decoding

This paper proposes a novel forward-backward four-way merger min-max algorithm and low latency check node unit (CNU) architecture for check node processing of nonbinary low-density parity check (NB-LDPC) codes. This algorithm derives simultaneously two output vectors for forward and backward processing in each step. A parallel switch network and parallel-serial elementary computation unit are proposed. Then, the CNU architecture corresponding to the algorithm is designed. The analysis and synthesis results show that the proposed CNU architecture obtains a latency reduction of 82.58% and 49.75% for any code rate without any loss performance, compared to previous works.