A Gram-Schmidt Based Lattice-Reduction Aided MMSE Detection in MIMO Systems

Abstract

This paper proposes an improved lattice-reduction aided (LRA) MMSE detection based on the Gram-Schmidt (GS) procedure. The proposed detection reduces the column vectors of the MIMO channel matrix using the LLL algorithm and the GS procedure to create mutually purely orthogonal column vectors of the reduced channel matrix. Then the decision boundary becomes the same as that for the ML detection. Compared to the conventional LRA MMSE detector, the proposed detector achieves much closer BER performances to those for the ML detector in both the 4 × 4 MIMO and the 8 × 8 MIMO systems.