A Novel Two-Stage Receiver for Space-Time Coded CDMA MIMO Systems

The space-time coded code-division multiple-access (ST-coded CDMA) has been widely investigated for the great demand of capacities and transmission rates in the future wireless communication systems. The blind Capon multiuser receiver was designed to achieve the goal by the linearly constrained minimum variance (LCMV) filter. However, the LCMV filter suffers the effects of finite samples and signature vector errors. In this paper, we proposed a novel two-stage receiver containing PA-GSC filters in parallel followed by the channel estimator and symbol detector. Two transformation schemes are designed in the PA-GSC filter. A performance enhancement method is introduced by using the forward-backward averaging technique. Besides, based on the weighting analysis, we also presented a simplified two-stage receiver with lower complexity. Computer simulations are given to demonstrate the effectiveness of the two-stage receiver for the ST-coded CDMA MIMO systems.