A Novel Soft-Input Soft-Output Reduced Complexity MIMO Trellis Detector

In this paper we propose a novel trellis based soft-input soft-output MIMO detector with significantly reduced search space. The performance of the detector is measured by evaluating the ultimate communication rate that is achievable for a system employing the novel detector; this limit corresponds to a mutual information that can be determined by standard methods. We also derive an expression that bounds the mutual information of interest and that can be optimized by numerical methods. Numerical results for many MIMO setups that illustrate the performance of the detector are also provided.