Performance of coded modulation on intersymbol interference channels

The authors examine the performance by simulation of trellis coded modulation (TCM), multiple-TCM, and block coded modulation on ISI (intersymbol interference) channels. Simulations were performed assuming that the receiver operates on the received signal using decision feedback equalization in conjunction with the Viterbi decoder. Results indicate that coded modulation schemes may be viable in systems that require low throughput rates. Coded schemes experience performance losses, however, in systems that require higher throughput rates, mainly because the equalization process cannot adequately reduce the distortion induced by the channel, and the Viterbi decoder is unable to operate on the distorted signal