The performance evaluation of combined CDMA-SDMA multi-user detection with parallel interference cancellation

This paper describes a novel performance evaluation technique of combined Code Division Multiple Access (CDMA) and Space Division Multiple Access (SDMA) multiuser receiver. The receiver detects users based on their code and spatial signatures. Exact calculation of the MAI interference is considered in this paper for a single sector cell that adopts combined CDMA-SDMA system, and accommodates an arbitrary K number of users transmitting their data. The Bit Error Rate (BER) expressions of any arbitrary user have been derived. Parallel Interference Canceller (PIC) is adopted as a suboptimum multiuser detector. Comparison between the performance of a CDMA system and Combined CDMA-SDMA system with and without PIC receivers are investigated. Our results show that the BER of a system with PIC is noticeably improved compared to the one without PIC (conventional multiuser receiver). Finally, the combined system enhances the system capacity by means of improving the BER performance.