A novel space-time turbo coding modulation technique for fading channels

A novel space-time turbo coding modulation technique is presented in this paper. At the encoder, information bits are encoded using a concatenated space-time turbo coder, and then coded symbols are modulated and assembled by a pre-defined function rather than punctured as in other schemes. It can achieve lower code rate (because it doesn´t puncture the coded signals), get more coding gains and take advantage of both space and time diversity. Since its decoding need to calculate two extrinsic probabilities simultaneously, traditional log-map decoding algorithm fails to be used directly. An extended 2-dimensional Log-Map decoding algorithm is developed to decode the proposed scheme. Simulation results and theoretical analysis exhibit its excellent performance. Under the same conditions, the proposed scheme will bring about 12 dB gains at BER 1.0 e-5 over some other known schemes at quasi-static fading channels, and above 10 dB at BER 1.0 e-5 over time-varying fading channels.