An Efficient Quasi-Maximum-Likelihood Multiuser Detector using Semi-Definite Relaxation

In the standard scenario of multiuser detection, the maximum-likelihood (ML) detector is optimum in the sense of minimum error probability. Unfortunately, ML detection requires the solution of a difficult optimization problem for which it is unlikely that the optimal solution can be efficiently found. In this paper, we consider an accurate and efficient quasi-ML detector which uses semi-definite relaxation (SDR) to approximate the ML detector. …