Linear Multiuser Detector 16 : 332 : 546 Wireless Communication Technologies Spring 2005

The large gaps in performance and complexity between the conventional single-user matched filter (MF) and the optimum multiuser detector motivate the search for other multiuser detectors that exhibit good performance/complexity tradeoffs [2]. This lecture examines various linear multiuser detectors. They can be implemented in a decentralized fashion where only users of interest need be demodulated, like the decorrelating detector which is optimal when the received amplitudes are completely unknown. The performance could be further improved if the information about the received signal-to-noise ratios is incorporable in the linear transformation. The lecture notes include the study of linear multiuser detectors both by decorrelating and nondecorrelating approaches, according to different criteria. The successive interference cancellation technique is introduced at the end.