MIMO Detection of 16-QAM Signaling Based on Semidefinite Relaxation

We propose a computationally efficient semidefinite relaxation (SDR) of the maximum likelihood (ML) detector for 16 quadrature amplitude modulation (16-QAM) in multiple-input multiple-output (MIMO) systems. The SDR stems from a variant of the ML problem, which utilizes set operation algorithms to formulate the alphabet constraint. Theoretical analysis and numerical simulations demonstrate that the proposed method can provide improved error performance as compared to some previous detectors.