Effects of channel estimation error in MC-CDMA/TDD systems

The multicarrier CDMA systems with time division duplex mode (MC-CDMA/TDD systems) can exploit the reciprocity between the uplink and downlink channels. The signal may be pre-equalized at the base station transmitter, based on the channel estimation during the previous reception time slot. This may lead to a reduction in complexity of the portable unit. However, since the channel is time varying in mobile communications environments, the estimate of the channel introduces error and this causes performance degradation. We analyze the channel estimation error and the BER performance of the MC-CDMA/TDD system with pre-equalization when the channel is time varying due to the mobile's motion.