Soft Semi-definite Relaxation for Detection of 16-QAM Signaling in MIMO Systems
Xu Xin①; Cai Yue-ming①②; Xu You-yun①
①Institute of Communications Engineering, PLAUST, Nanjing 210007, China;②National Mobile Communications Research Laboratory, Southeast University, Nanjing 210096, China
Abstract:In this paper, soft semi-definite relaxation for detection of 16-QAM signaling in MIMO systems is investigated. Additional constraints and dimension-reduction approximation method are proposed, which can be used to calculate the Log-Likelihood Ratio (LLR) and reduce dimensions of the SDR detection, respectively. Simulations show that the soft SDR detector exhibits a better performance in a flat-fading MIMO channels, and the complexity of the soft detector is considerably reduced by reducing the dimensions of the SDR programming, but the performance loss leads by dimension reduction is about 0.2 to 0.4 dB.