Reduced Complexity Detection for Ricean MIMO Channels Based on Condition Number Thresholding

In this paper, a novel adaptive detection scheme for the case of multiple-input multiple-output (MIMO) Ricean channels with two transmit and receive antenna elements is presented. Our prime aim is to reduce the extensive complexity of maximum-likelihood (ML) detectors by developing an adaptive scheme which switches between a ML and a much simpler zero-forcing (ZF) detector depending on the instantaneous spatial conditions. The kernel of the adaptive detector (AD) is a hard-decision criterion based on the condition number of the MIMO correlation matrix. It is demonstrated that the proposed scheme offers a remarkable reduction in terms of complexity along with a satisfactory performance when specifically designed antenna arrays are employed.