Extended hamming and BCH soft decision decoders for mobile data applications

A methodology is presented for the design and development of efficient trel lis-based soft decision decoders for extended Hamming and BCH codes. A new metric for noncoherent discriminator detection is proposed that substantial ly improves the performance of trellis-based decoders over additive white G aussian noise (AWGN) channels. Minimal edge trellises are then presented fo r the class of extended Hamming codes and the (32, 21) extended BCH code, T he latter is in extensive use in narrow-band wireless data systems, An auto matic request (ARQ) protocol is described that allows the soft decision dec oders to outperform their hard decision counterparts in both reliability an d throughput.