GMD-enhanced MU-MIMO for IEEE 802.11ac

This paper proposes a multiuser multiple-input multiple-output orthogonal frequency division multiplexing (MU-MIMO-OFDM) technique suitable for IEEE 802.11ac. The proposed approach is based on a judicious combination of singular value- and geometric mean decompositions (SVD/GMD) of the channel matrix. This precoding techniques are then combined with a user selection procedure that preserves fairness among users. Remarkably, it is shown that a cautious use of the GMD leads to a throughput enhancement in comparison to classical approaches that exclusively rely on the SVD. Simulations are presented in the context of IEEE 802.11ac demonstrating the benefits of the proposed technique.