A sequential soft-decision decoder for Reed-Solomon codes appliedto encoded PSK in Rayleigh-fading channels

摘要

A soft-decision stack algorithm with a variable-bias-term branchnmetric and accurate channel state information estimate is applied to anReed-Solomon-encoded phase-shift keying (PSK) system in the presence ofnmemoryless Rayleigh fading. To compensate for the variable decodingndelay inherent in sequential decoding algorithms, a time-out mechanismnis used by the inner decoder: if a time-out occurs before completendecoding of a given block, the decoder declares an erasure. Annerasures-and-errors correction decoding algorithm is implemented at thenouter decoder to recover any incorrect or incompletely decoded innerncode words. Simulation results show that significant improvement overnuncoded modulation can be achieved with this approach with moderate costnin decoding complexity