A robust low-complexity MIMO detector for rank 4 LTE/LTE-A systems

This paper deals with MIMO detection for rank 4 3GPP Long-Term-Evolution (LTE) systems. The paper revolves around a previously known detector [1], which we shall refer to as RCSMLD (Reduced-Constellation-Size-Maximum-Likelihood-Detector). However, a direct application of the scheme in [1] to LTE/LTE-A rank 4 test cases results in unsatisfactory performance. The first contribution of the paper is to introduce several modifications that can jointly be applied to the basic RCSMLD scheme which, taken together, result in excellent performance. Our second contribution is the development of a highly efficient hardware structure for RCSMLD that allows for an implementation with very few multiplications.