Optimal HMM Processing Of Differentially Phase Modulated Communication Systems

Abstract

This paper investigates demodulation of differentially phase modulated signals (DPMS) using optimal HMM filters. The optimal HMM filter presented in the paper is computationally of order N 3 per time instant, where N is the number of message symbols. Previously, optimal HMM filters have been of computational order N 4 per time instant. Also, suboptimal HMM filters have be proposed of computation order N 2 per time instant. The approach presented in this paper uses two coupled HMM filters and exploits knowledge of their interdependence to achieve computational gains. A simulation study is also presented.