Metric for noncoherent sequence estimation

A novel simple noncoherent sequence estimation (NSE) metric for M-ary differential phase-shift keying (MDPSK) transmission over intersymbol interference (ISI) channels is proposed. In contrast to previously reported NSE schemes; the phase reference symbol required for metric calculation can be obtained efficiently in a recursive manner. Simulations demonstrate the high performance of the novel scheme, which can approach the performance of coherent maximum-likelihood sequence estimation (MLSE) while the complexity of metric computation remains relatively low.