A Flexible Tree Searching Scheme for MIMO Detection

Detection is one of the key technologies in multiple-input multiple-output system. In this paper we propose a new tree searching scheme which is flexible in the tradeoff between performance and complexity. Sorted QR decomposition based on minimum mean square error (MMSE) criteria is applied as a preprocessing to make the channel easier for tree searching and Fano bias, which is adjustable to achieve a good tradeoff between performance and complexity, is applied in the radius setting for different layer to more efficiently prune the leaves. Much smaller complexity is needed by the proposed scheme with negligible performance degradation compared with that of sphere decoding scheme, especially in the scenarios of larger number of transmitter antennas and high order modulation. Simulations accommodate our conclusions.