Code matched interleaver for parallel concatenated trellis coded modulation

A design method of a code matched interleaver (CMI) for parallel concatenated trellis-coded modulation (TCM) is proposed. By reducing some input symbol sequences of weight 2, which give large contribution to the error probability, and combining with S-random, we can arrive at a particular interleaver which might improve error performance and lower the "error floor" at moderate to high signal-to-noise ratio (SNR). By comparing the results of simulation on an AWGN channel for different types of interleaver when applying the modified BCJR (Bahl-Cocke-Jelinek-Raviv) decoding algorithm, the proposal is shown to be effective.