Compromise in decoding for a concatenated turbo and space-time block coded system

In this paper, we investigate the performance of iterative decoding for concatenated Turbo coded and Space-time block coded (STBC) system. In our proposed system the soft parity bit needs to be estimated, which differs from traditional Turbo decoding, as the receiver adopts iterative decoding not only to Turbo codes but the entire system. In this case a simplified and effective method of parity bit estimation is presented, which we focus on, resulting in a moderate increase of complexity. Simulation results demonstrate that performance improvement can be obtained using the iterative scheme. Meanwhile the increase of complexity caused by iteration and parity bit estimation in exchange for performance improvement is considered. Our proposed scheme makes an optimal trade-off between complexity and performance for transmitting in Rayleigh fading channel.