Semi-Blind Multiuser Detector for Reverse

The recently developed blind multiuser detec- tion techniques in DS-CDMA systems mainly deal with the demodulation of a desired user's data with the prior knowl- edge of only the signature sequence of that user. However, in the CDMA reverse link, the base station knows the sig- nature sequences of users in its cell, but has no knowledge of interfering users from other cells. In this paper, we de- velop a class of novel semi-blind technique for multiuser de- tection in such a scenario. This approach fully utilizes all known users' information, performs multistage parallel or serial interference cancellations to suppress the interferers within the cell, and exploits blind adaptive decision-feedback MMSE detector to suppress the inter-cell interference. The performance of the proposed detector is found to have sig- nificantly better performance than that of the purely blind detectors and the non-blind detectors.