Multiuser detector performance comparisons in multirate CDMA systems
Markku J. Juntti · 2002
The performance of the multi-code (MC) access system with one processing gain and the multiple processing gain (MPG) access for asynchronous multirate code-division multiple-access (CDMA) systems are considered. The bit error rates (BER) of the decorrelating, parallel interference canceler (PIC) and groupwise serial interference canceler (GSIC) with either the PIC or decorrelator within the group are compared. The results show that the decorrelating and the GSIC multiuser detectors yield the best performance. For all interference cancellation schemes the BER saturates at high SNRs due to decision errors degrading the multiple-access interference (MAI) estimates. The problem is particularly severe with the PIC detector.