Block CMA-based blind and group-blind multiuser detectors

We derive a new iterative multiuser detection algorithm based on a generalized sidelobe canceller which uses the constant modulus property of digitally modulated signals together with code knowledge given to a receiver in a CDMA system. The proposed algorithm can be seen as an extension of the least squares constant modulus algorithm in a sense that it simultaneously minimizes the constant modulus (CM) and the least square (LS) cost functions iteratively. The proposed detector performs as well as the ideal MMSE detector in the high SNR region, in addition to resolving the interference capture problem existing in most constant modulus algorithms (CMA).