Soft parallel interference cancellation for a turbo coded uplink MC-CDMA system

A novel parallel interference cancellation receiver for QAM modulated turbo coded uplink MC- CDMA systems has been proposed. In the receiver, the multi-stage partial soft parallel interference cancellation has been applied. The receiver employs the new adaptive minimum mean square combining, so that the system is able to adjust the equalization gain coefficients in every iterative stage adaptively. In addition, unlike some previous work that has drawbacks of the complexity, latency and error amplification resulting from the decoder in every iteration step, the soft in soft out (SISO) inverse bit mapper and simplified SISO bit mapper are used in the receiver. The partial cancellation is also implemented to further improve the receiver performance. The simulations are carried out in a realistic multi-user environment: modified 802.16 Stanford University Interim (SUI) channel model. Both analysis and simulations indicate that our proposed receiver can achieve a considerably good performance with a low complexity structure compared with traditional systems.