EM-based multiuser detection and parallel interference cancellation for space-time block coded WCDMA systems employing 16-QAM over multipath fading channels

We consider the design of iterative multiuser detectors based on the expectation-maximization (EM) algorithm and parallel interference cancellation (PIC) for spacetime block coded (STBC) WCDMA employing 16-QAM in multipath fading channels. We show that the EM-based and PIC receivers improve the receiver performance particularly when two receive antennas are employed. We see that EM receiver shows better performance than PIC. In fact, the PIC is a special case of our proposed EM-based detector.