A Sorted Feedback Non-linear Quantization Algorithm for Lattice Reduction Aided MIMO Detection

Lattice reduction technology has been proved to improve MIMO system performance recently, but the complexity of optimum quantization algorithm is high due to constellation biased distribution caused by signal transformation. In this paper, a sorted feedback non-linear quantization (SFQ) scheme is proposed, which considers both the border of transformed constellation and the correlations between signal elements, and the elements are selected to be quantized according to quantization errors. The simulation results show that the performance of lattice reduction aided (LRA) MIMO detectors based on the proposed quantization scheme is superior to that of LRA MIMO detectors based on non-sorted feedback and independent element-wise quantization schemes. The proposed algorithm can approach the performance of maximum likelihood detection in polynomial complexity in a flat block fading channel.