Abstract
Code Division Multiple Access (CDMA) has become an important access scheme in recent years because of its several advantages such as higher capacity, anti-jamming, etc. However, one of the serious shortcomings of CDMA system is the multiple access interference (MAI). The multiple access interference is produced when there are multiple users using the same frequency band simultaneously in the CDMA system. The other source of interference is the multipath effect. Both of them degrade the performance of the CDMA system. In order to suppress the interference, several multiuser detectors have been proposed, including the parallel interference cancellation (PIC) scheme. In this thesis, an algorithm is proposed, which combines the parallel interference cancellation scheme with the interference projection method. The PIC scheme, which is constructed by several matched filters stage-by-stage, makes use of the adaptive iteration to improve the performance of the conventional receiver. In the conventional PIC scheme, the transmission power of every user must be known beforehand to arrive at a correct MAI estimation in the cancellation process. By utilizing the interference projection method in the PIC scheme, the transmission power of every user can be estimated, and a good performance of the receiver is retained.