NB-LDPC check node with pre-sorted input

International audienceNon-binary low-density parity-check codes have better communication performance compared to their binary counterparts but they suffer from higher complexity, especially for the check node processing. In this paper a sorting of the input vectors based on a reliability criteria is performed prior to the check node processing. This presorting process allows the Extended Min-Sum (EMS) check node process to focus its effort mainly on the weakest inputs. Proof is given for a check node of degree 12 in GF(64) for the syndrome based algorithm with a number of computed syndromes reduced by a factor of four which directly impacts the check node complexity without performance degradation. Index Terms—NB-LDPC, Check Node, syndrome-based, EMS