Extended minsum algorithm for decoding LDPC codes over GF(/sub q/

In this paper, we develop a generalization of the minsum (MS) algorithm which not only performs additions without the need of channel estimation, but also with the two following objectives: (i) a complexity much lower than O(q²) so that finite fields of large order can be considered; and (ii) a small performance degradation compared with BP decoding. The first objective is achieved by introducing configuration sets, which allow to keep only a small number of meaningful values at the check node processing. The second objective is achieved by applying at the variable node processing the correction techniques of J. Chen and M. Fossorier, (2002) to the proposed algorithm