A new trellis source encoding method and its application on joint source and channel coding

Abstract

In this paper, a new source encoding scheme is presented. It is a trellis coded quantization scheme which is based on ring convolutional codes. Joint Source and Channel Coding (JSCC) using trellis coded Continuous Phase Modulation (CPM) with convolutional codes over rings is investigated. The channel is assumed to be an Additive White Gaussian Noise (AWGN) channel. Optimal soft decoding for the proposed JSCC scheme is studied. The soft decoder is based on the A Posteriori Probability (APP) algorithm for trellis coded CPM with ring convolutional codes. It is shown that these systems with soft decoding outperform the same systems with hard decoding especially when the systems operate at low to medium Signal-to-Noise Ratio (SNR). It has been demonstrated that TCQ based on ring convolutional codes is superior to conventional TCQ of the same complexity. The novelties of this work are the development of a TCQ method based on ring convolutional codes, the use of a soft decoder and the APP algorithm for the combined systems.