A Viterbi Algorithm for Modulo-2 pi Phase Tracking in Coherent Data Communication Systems.
Louis L. Scharf, Siddiqui, M M · Defense Technical Information Center (DTIC) · 1977
It is argued that only phase, modulo-2 pi, is of interest in data communication applications. The probabilistic evolution of random walk phase, modulo-2 pi, is studied and the results used to derive a MAP sequence estimator for phase on the interval (-pi, pi). The MAP sequence estimator is a Viterbi tracker (or dynamic programming algorithm) for tracking phase on a finite-dimensional trellis in (-pi, pi). Computational requirements are discussed and several representative simulations are included. Applications of the algorithm to carrier phase tracking in coherent data communication systems are outlined. (Author)