In this thesis, the performance improvement of uplink coded MC-CDMA system with a low-complexity iterative receiver was proposed. The iterative receiver consists of two stages: a soft-input soft-output multiuser detector and a set of single-user channel decoders. The role of the multiuser detection and the decoder is to compute the extrinsic information which is fed to the next stage for using as a priori information. The complexity of the optimal computation, based on maximum a posteriori (MAP) criteria for the multiuser detection, is prohibitive. Hence, a soft interference cancellation approach is proposed. The multiuser minimum mean square error (MU-MMSE) detector is used in the first stage of the cancellation. The simulation results show that the iterative soft interference cancellation using multiuser MMSE is better than the conventional receiver. In addition, the partial cancellation technique where only fraction of interference replica is cancelled from the composite signal is also proposed. To reduce the complexity of the iterative soft interference cancellation using multiuser MMSE in the first stage of the cancellation, the partial cancellation technique is applied to the iterative soft interference cancellation using matched filter in the first stage of the cancellation. The simulation results show that the performance of the receiver using matched filter in the first stage of the cancellation can be improved by using the partial cancellation technique.
