Performance of adaptive multistage interference canceller for multi-carrier CDMA systems

Abstract

In this paper, we propose an adaptive multistage partial parallel interference cancellation (PPIC) multiuser detector for multi-carrier direct-sequence code-division multiple-access (MC-CDMA) communication systems over frequency selective fading channels. The PPIC, which tries to reduce the cancellation error in parallel interference cancellation (PIC) schemes due to the wrong interference estimations in the early stages, outperforms the conventional PIC under the heavy load for CDMA systems. Then, in this paper, a partial factor (PF) derived from the estimated multiple access interference (MAI) is proposed to adapt the channel variations and perform more effective PPIC for MC-CDMA systems. Simulation results show that the proposed five-stage adaptive PPIC scheme outperforms the conventional PIC (CPIC) and constant weight PPIC (CW-PPIC) with highly near-far resistant and robust to the channel variations, especially at heavy system load.