Reduced-complexity sequence estimation for trellis coded modulation with outer Reed-Solomon codes over ISI channels

Abstract

The combined linear-Viterbi equalizer (CLVE) is a class of receivers employing a linear filter before the Viterbi algorithm (VA) in order to shape the original channel impulse response (CIR) to some shorter desired impulse response (DIR) which allows a lower complexity VA. The CLVE technique is originally proposed to reduce the complexity of VA that performs maximum likelihood sequence estimation (MLSE) to uncoded transmission over intersymbol interference (ISI) channels. In this paper, we adopt the CLVE technique to reduce the complexity of VA that performs MLSE to trellis coded transmission over ISI channels. Furthermore, reduced state sequence estimation for high rate concatenated systems with bandwidth efficient trellis inner codes and Reed-Solomon (RS) outer codes over ISI channels is investigated.