Phase and symbol sequence decoding on random walk phase channels

Abstract : Consider the problem of estimating phase and decoding data symbols from baseband data. Assume the phase sequence is a random walk on the circle and the symbols are drawn independently from an equiprobable alphabet for transmission over a perfectly equalized channel. A dynamic programming algorithm (Viterbi algorithm) is derived for decoding a maximum a posteriori (MAP) phase-symbol sequence on a finite dimensional phase-symbol trellis. Simulation results for binary and 8-ary phase modulated (PM) symbol sets are presented. (Author)