Multi-stage PIC receiver with decision thresholds over rayleigh fading channel

Parallel interference cancellation (PIC) is a family of low complexity multi-user detection methods for DS/CDMA systems. The performance of the multistage PIC depends on the decision function used in the interference cancellation. In this paper, we propose to provide the performance of PIC receiver using Xha function `clipping´ with respect to decision threshold value. The decision threshold determines how much MAI is to be cancelled with hard decision and high probability. Otherwise, we used a soft bit decision to cancel only the interference of unreliable users form the received signal. This approach is original compared to PIC receiver with decision thresholds using null zone hard decision. It is shown that the proposed detector performs well under realistic conditions, particularly in the case of error optimisation of decision threshold value.