Optimization of sliding window algorithm for space-time turbo trellis codes

The design of space-time turbo trellis codes (ST Turbo TC) for improving the bandwidth efficiency and the reliability of wireless data networks, which is based on the turbo structure, has been proposed in the literature. However, like other turbo based coding schemes, the fundamental problems with the ST Turbo TC decoder are its complexity and decoding delay. In some cases the decoding delay may be so long that the use of ST Turbo TC system is unattractive for time sensitive applications. The aim of this paper is to propose a simplified ST Turbo TC decoder using the sliding window technique in order to achieve memory savings and reduce decoding delay. In particular, we consider the performance of QPSK ST Turbo TC schemes on fast fading channels for various system parameters. Different window sizes are employed and investigated. Through computer simulation, the optimum window sizes are defined for different system parameters