Architecture of a low-complexity non-binary LDPC decoder for high order fields

In this paper, we propose a hardware implementation of the EMS decoding algorithm for non-binary LDPC codes, presented in [10]. To the knowledge of the authors this is the first implementation of a GF(q) LDPC decoder for high order fields (q >= 64). The originality of the proposed architecture is that it takes into account the memory problem of the nonbinary LDPC decoders, together with a significant complexity reduction per decoding iteration which becomes independent from the field order. We present the estimation of the non-binary decoder implementation and key metrics including throughput and hardware complexity. The error decoding performance of the low complexity algorithm with proper compensation has been obtained through computer simulations. The frame error rate results are quite good with respect to the important complexity reduction. The results show also that an implementation of a nonbinary LDPC decoder is now feasible and the extra complexity of the decoder is balanced by the superior performance of this class of codes. With their foreseen simple architectures and good-error correcting performances, non-binary LDPC codes provide a promising vehicle for real-life efficient coding system implementations.