Optimization of Linear Dispersion Codes for Wireless Relay Networks

A design method is introduced for linear dispersion (LD) space-time codes in wireless relay networks under Rayleigh fading channels. The codes are designed with a stochastic quasi-gradient algorithm to minimize the upper bound of the average pairwise error probability. Simulation results show that the optimized codes achieve a coding gain of about 2 dB over codes that are randomly generated based on the isotropic distribution.