Performance of phase-invariant trellis coding for differentially-encoded coherent M-PSK signals on Rayleigh fading channels

Rate(n-1)/n phase-invariant trellis coding with unquantised maximum-likelihood Viterbi decoding for differentially-encoded coherent M-ary (M-2ⁿ) PSK signals on Rayleigh fading channels is considered. The simulated bit error probability performance of the trellis-coded modulation is presented for four- and eight-state linear and nonlinear codes for constraint lengths 3 and 4, respectively, with coding gains of at least 2.5 dB at a bit error rate of 10^-3.