Jointly optimised iterative source-coding, channel-coding and modulation for transmission over wireless channels

Joint source-coding, channel-coding and modulation schemes based on variable length codes (VLCs), trellis coded modulation (TCM), turbo TCM (TTCM), bit-interleaved coded modulation (BICM) and iteratively decoded BICM (BICM-ID) schemes are proposed. A significant coding gain is achieved without bandwidth expansion, when exchanging information between the VLC and the coded modulation decoders with the advent of iterative decoding. By using independent interleavers for the in-phase and quadrature-phase components of the complex-valued constellation, further diversity gain may be achieved. The performance of the proposed schemes is evaluated when communicating over both AWGN and Rayleigh fading channels. Explicitly, at BER=10^-5 most of the proposed schemes have BER curves around 2 dBs away from the channel capacity limit.