A Threshold-Selective Multiuser Downlink MAC Scheme for 802.11n Wireless Networks

The recently approved 802.11n standard establishes the integration of MIMO technology in WLANs with the goal of achieving high data rates. However, it does not exploit the multiuser capabilities of the MIMO channel. In this paper we present a multiuser downlink transmission scheme that combines low-complexity beamforming at the Physical layer with an opportunistic channel-aware MAC scheduling policy. A mathematical model for the throughput calculation of the proposed scheme is presented and validated through link-layer simulation results.