Semi-blind multiuser detector for reverse link in CDMA systems

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