VITERBI DECODER INCORPORATING SUBOPTIMAL MAXIMUM LIKELIHOOD CARRIER PHASE ESTIMATION.

Abstract

The authors consider the detection of convolutionally coded data received over the additive white Gaussian noise channel with unknown carrier phase. An algorithm is developed for simultaneous maximum-likelihood (ML) data decoding and suboptimal ML carrier-phase estimation. The algorithm does not increase the number of states in the Viterbi decoder, and it readily implementable. For a circular signal constellation, the algorithm leads to a totally linear receiver. The performance of the algorithm is obtained using computer simulations with a time-varying phase given by two different models. The error-rate results indicate that the algorithm provides good performance.