Decorrelating receivers of differential space-time coded CDMA systems

Capitalizing on code-division multiple-access (CDMA) and amicable orthogonal design, we propose a space-time (ST) transmission scheme for multiple-antenna systems, which allows full-diversity noncoherent communications and is resistant to multiuser interference (MUI). We then derive a differential decorrelating receiver (DDR) for flat Rayleigh fading channels, which decouples not only the detection of different users but also the decoding of different data symbols. The basic ideas of our design are as follows: decorrelating receiver eliminates MUI, and converts multiuser environments to single ones; while channel estimates are not available at the receivers, differential ST coding exploits ST diversity to improve the anti-fading performance of CDMA systems. Computer simulation results are given to support our development.