Detection of trellis-coded modulation on time-dispersive channels

Bandwidth efficient trellis coded modulation (TCM) is frequently used in digital communication to reduce the required signal-to-noise ratio for achieving a specified error rate without bandwidth expansion. In time-dispersive channels, however, effective equalization techniques have to be used in order to reduce the intersymbol interference (ISI) at the input of the decoder. A new technique for detecting TCM signals on time-dispersive channels is proposed. Simulation results show that the proposed technique achieves a significant gain in noise margin over a receiver which uses conventional DFE and Viterbi decoder. An analytical upper bound of the proposed technique is also derived, which, although requiring numerical approximation for evaluation, are tight for a wide range of time-dispersive channels