Combining Transmit Diversity Schemes for Multicarrier Systems

In this paper, we present a synchronous multicarrier code division multiple access scheme for the uplink. We apply interleaved and block spreading schemes for Rayleigh and Rice fading channels. Enhancing diversity in the uplink is feasible by applying transmit diversity schemes. Therefore, we compare cyclic delay diversity (CDD) with the Alamouti scheme. Increasing the number of transmit antennas to four enhances the performance even further. For this we combine the Alamouti scheme with CDD and compare the performance. Nevertheless, we show that receiver diversity at the base station improves the performance significantly, but can still exploit the additional transmit diversity offered by the mobile.