Patent attributes
A method for differential phase evaluation of M-ary communication data is employed in which the data consists of N sequential symbols r1 . . . rN, each having one of M transmitted phases. Selected sequences of N−1 elements that represent possible sequences of phase differentials are evaluated using multiple-symbol differential detection. Using r1 as the reference for each phase differential estimate, sN−1 phase differential sequences are selected in the form (P2i, P3i, . . . , PNi) for i=1 to s for evaluating said symbol set, where s is predetermined and 1<s<M. Each set of s phase differential estimate values are chosen based on being the closest in value to the actual transmitted phase differential value. These s phase differential estimates can be determined mathematically as those which produce the maximum results using conventional differential detection.
