Performance bounds for trellis-coded modulation on time-dispersivechannels

The performance of trellis-coded modulation (TCM) on additive white Gaussian noise channels is well understood, and tight analytical bounds exist on the probability of the Viterbi decoder making a decision error. When a channel is also time-dispersive, the performance of TCM systems has been studied mainly by simulation. However, simulation is limited to symbol error probabilities greater than 10^-6 and is not a particularly useful tool for designing codes. Tight analytical bounds on the error probability of TCM on time-dispersive channels are required for a more thorough study of performance. Moreover, the design of good codes and optimum metrics for time-dispersive channels requires tight analytical bounds. In this paper we derive analytical upper bounds, which, although requiring numerical techniques for tractable evaluation, are tight for a wide range of time-dispersive channel conditions. The bounds are based on a union bound of error events that leads to a summation of pairwise error probabilities, which are themselves upper bounded