Reduced Complexity of RD Detector Based on Semi-definite Relaxation for MIMO Systems

The Maximum likelihood (ML) detection problem in multiple-input multiple-output(MIMO) channels is a NP-hard problem. However, it has optimum performance. The semi-definite relaxation (SDR) detector is an alternative to ML detection. In this paper, we propose the reduced complexity of Reliability Discrimination (RD) detector based on semi-definite relaxation for MIMO systems. We obtain an initial estimated symbol of the received symbol by Zero forcing (ZF) detector and discriminate the reliability of the initial estimated symbol with RD algorithm. If the reliability of the estimated symbol is high, the estimated symbol is available as transmitted symbol, or else we search for the most reliable symbol by SDR detector. The proposed method has proved to significantly reduce computational complexity and has near optimal performance in simulation.