Multiuser MAC Protocols for 802.11n Wireless Networks

The emerging 802.11n standard establishes the integration of MIMO technology in WLANs with the goal of achieving high data rates. However there are still many open issues regarding MAC protocol design for MIMO based systems, especially in order to exploit the multiuser capabilities of the MIMO channel. In this paper we investigate practical solutions to implement multiuser downlink transmission in infrastructure 802.11n based WLANs. A low-complexity beamforming transmission technique is employed at the physical layer and four MAC schemes that vary in complexity and efficiency are presented and evaluated through computer simulations.