A new tandem source-channel trellis coding scheme

The author presents a new tandem source-channel coding scheme consisting of a trellis source coder and a trellis-coded modulation (TCM) channel coder. The motivation for the use of TCM, instead of conventional channel coding schemes such as convolutional codes, arises from the fact that by using TCM, improvement in the signal-to-quantization-noise ratio (SQNR) is achieved without bandwidth expansion. Criteria for the choice of TCM codes are discussed, and TCM schemes suitable for this application are presented. Simulation results for both a Gauss-Markov source and speech samples indicate that the present scheme results in considerable improvement not only over uncoded transmission but also in comparison with the joint source-channel trellis coding.