Optimal precoder selection for MIMO systems with ML detection at the receiver

In this paper, we propose a computationally efficient algorithm for optimal precoder selection in spatially multiplexed MIMO systems with ML detection at the receiver. Previous suboptimal selection techniques are based on lower bounds of Euclidean distance in order to lower complexity, thus compromise the optimality. We exploit the concept of sphere decoding (SD) for precoder selection and perform SDs in a selective manner to reduce the processing time without compromising the optimal performance.