On the iterative decoding of multilevel codes

摘要

Iterative decoding of multilevel coded modulation is discussed.nDespite its asymptotic optimality with proper design, the errorncorrecting capability of multilevel codes may not be fully exploited fornfinite block length with conventional multistage decoding. This factnstems from the suboptimality of multistage decoding giving rise tonincreased error multiplicity at lower index stages and the associatednerror propagation to higher stages. Such problems can be overcome innmany situations by introducing iterative decoding which oftennsignificantly compensates the suboptimality of a staged decoder. Thenclass of multilevel codes achieving practically important bit-errornperformance near the Shannon limit becomes far wider with iterativendecoding