Transmit multi-antenna diversity for TDD MC-CDMA

Jeong and Nakagawa (2000) proposed a selection type transmit diversity scheme for TDD MC-CDMA with asymmetric modulation on a duplex channel. In the scheme, the performance degraded rapidly at a large number of users even though it showed good performance at a small number of users. In this paper, we propose a new transmit diversity scheme for the TDD MC-CDMA system using multiple antennas. Computer simulation is carried out to evaluate the system performance and the performance is compared with that of the selection type transmit diversity scheme. From the simulation results, it is found that the proposed system has a good performance at a large number of users and thus, the transmit diversity scheme should be chosen applicably at the base station according to the number of users