An improved differential detector for coded PSK modulations in Rayleigh fast-fading channels

This paper demonstrates the use of multiple-symbol differential detection in trellis coded differential M-ary phase shift keying modulation schemes over correlated flat Rayleigh fading channels. This technique exploits the statistics of the fading channels to improve the error performance of the system without sacrificing the advantage of the time diversity attribute of trellis coded modulation. Optimal metrics are obtained for the Viterbi decoder. By using a closed form analytical expression and computer simulations for bit error rate performance, the authors show that the technique is able to suppress the irreducible error floor associated with conventional differential TCM