A phase ambiguity resolution technique for TCM

Abstract

The authors present the simulation model, performance evaluation, and hardware implementation of a technique to resolve phase ambiguity in trellis-coded modulation (TCM) where the popular Viterbi algorithm is utilized. While this approach has been used with BPSK (binary phase shift keying) and QPSK (quadrature phase shift keying), its application to multilevel modulation schemes (M>4) is novel and of interest because it provides a viable alternative to rotationally invariant codes. This approach does not require any arithmetic computations and can be accomplished with minimal hardware. The results presented here are being used to implement a 32-sector phase-quantized TCM system utilizing 8 PSK modulation.