Self-concatenated trellis coded modulation with self-iterative decoding

Self-concatenated trellis coded modulation with b(g-1) interleavers is a concatenated coded scheme based on only one rate bq/n convolutional code. The b input information sequences and their permuted versions are connected through b(q-1) interleavers to the bq inputs of the convolutional encoder. A subset of the output, including the b information bits and parity bits, is mapped to modulation signals, e.g., MPSK, MQAM. First we obtain an upper bound to the average maximum-likelihood bit error probability of the self-concatenated convolutional coding scheme for binary modulation which also applies to QPSK modulation. Design rules for the single convolutional code, that maximize the interleavers gain and the asymptotic slope of the error probability curves are presented. The asymptotic error performance and design rules for binary modulation are extended to non-binary modulations for the design of self-concatenated trellis coded modulation. A low complexity self-iterative decoding algorithm for self-concatenated trellis coded modulation is proposed. Examples of self-concatenated coding/decoding are given for binary modulation with q=2, b=1, and 8-PSK modulation with q=2, b=2. Finally, simulation results for the examples are given for short and long interleavers, using the self iterative decoder.