Low computational complexity multiuser detection using multibeam antennas

The optimal multiuser detector requires extremely high computational complexity. Sub-optimal multiuser detectors can alleviate the problem but still require considerable computational complexity. In this paper, we consider incorporating a multibeam antenna into the multiuser detector to effectively reduce the computational complexity. A method that is well suited to multibeam multiuser detection which we term as "partial decorrelation" is proposed. Closed form error of probability as well as analytical and numerical results of this partial decorrelation detector are given.