Low-Complexity Soft Detection of QAM Demapper for a MIMO System

摘要

MIMO systems exploit multipath propagation to improve throughput and performance of digital communication systems. However, at the receiver side, the computation of Euclidean distances requires prohibitive computational complexity particularly when combined with a high-order constellation. Conventionally, it is necessary to calculate all the Euclidean distances to find the maximum likelihood solution. In this letter, we propose a novel approach based on the principle of conditioned detection combined with lattice-reduction techniques to estimate the closest point to the received symbol without the computation of all the Euclidean distances. Thanks to this approach, a reduction up to 95% of the required number of multiplications is achieved without any degradation in terms of performance by comparison with a conventional BP technique.