Performance of trellis-coded modulation on frequency-selective Rayleigh fading channels with soft-output algorithms

Trellis-coded modulation (TCM) is well-known for achieving coding gain in the presence of additive white Gaussian noise (AWGN) without any bandwidth or power expansion. This property makes it a very attractive scheme to be used in the mobile fading environment where both bandwidth and power are precious resources. The possibility of applying TCM in the presence of additive noise and frequency-selective fading are considered. In particular, various receiver structures with moderate complexity are investigated together with the Ungerboeck´s (1982) 8-PSK TCM schemes. The simulation results show that with the proper choice of soft-output algorithm, a coding gain of 4 dB to 6 dB can be achieved at a bit error rate level of 10^-3