A new application of DS-CDMA in BLAST systems

Bell layered space-time architecture (BLAST) is a multi-antenna communication structure with high spectrum efficiency, and it has found wide applications in LANs and WANs. However, since it does not make full use of the diversity provided by multiple antennas, its performance is much poorer than other space-time coding approaches. A new application of DS-CDMA in BLAST is proposed; it introduces orthogonal spreading sequences (OSS) into the transmitter while it retains the basic structure of BLAST. The proposed receiver suppresses interference from other antennas by the orthogonality contained in the received signals, and extracts information from each receive antenna using the RAKE receiver principle to construct an efficient statistical decision. Simulation results show that the proposed system achieves good performance over flat fading channels at the cost of a little loss in spreading spectrum.