Ordered statistics decoding of linear block codes on frequency nonselective multipath channels

Abstract

This paper investigates the performance of ordered statistics decoding (OSD) of linear block codes with binary differential phase-shift-keying (2DPSK) transmission on frequency nonselective multipath channels. First, the wireless channel is modeled as a frequency nonselective, slow fading environment without intersymbol interference. Second, block interleaving is embedded to decorrelate the successive received symbols so that the performance of OSD, designed essentially for memoryless channels, is retained. Third, we derive the log-likelihood ratio of received symbols based on 2DPSK modulation. Fourth, we derive the statistics of received symbols and the statistics of received symbols after ordering. Further, we analyze the system error performance for sufficient degree of interleaving. Specifically, we derive the asymptotic bit error rate (BER) of OSD at high SNRs using the first-order approximation, finally, we conduct experiments at various channel characteristics and interleaving degrees for (128, 61, 22) extended BCH code and (24, 12, 8) extended Golay code. Results show that the error performance improves tremendously with increased interleaving degree.