The Performance of Space-Time Spread Spectrum LS-CDMA System over Fading Channel

Loosely-synchronized code division multiple access (LS-CDMA) system is able to completely eliminate the inter-symbol interference and multiple access interference because of the good autocorrelation and crosscorrelation property of LS codes, which results in great enhancement of system performance and potential capacity as compared to ordinary CDMA systems. By combining such LS-CDMA technology with the space-time coding technology, space-time spread spectrum LS-CDMA system can get more advantages such as spatial diversity when more than one antennas are installed in the system. Both the transmitter scheme and the receiver structure of such space-time spread spectrum LS-CDMA system using multiple transmitting antennas and only one receiving antenna are put forward in this paper. In case of fading channel, it is possible for the system to achieve both temporal diversity and spatial transmit diversity. Some simulation results, as well as a few conclusions are given.