Quantization Error Correction Scheme for Lattice-Reduction Aided Linear Detection in MIMO Systems

Recently, lattice reduction aided (LRA) detector has been introduced into conventional detectors for MIMO systems, to improve the performance. In LRA detectors, the first quantization step is simply a rounding operation, regardless to the original constellation. Sometimes, it causes quantization error that makes the obtained point to lie outside of the original constellation. In this paper, we propose a method to reduce the effect of quantization error. We investigated and found out that almost every time detection errors occur there are also quantization errors. Sphere detector (SD) is combined to get the optimal solution in case of quantization error. Simulation shows that the combined SD-LRA- detectors gives significant improvement with slightly additional complexity.