Short for Multi-User, Multiple-Input, Multiple-Output, MU-MIMO is an enhanced form of the MIMO technology that enables multiple independent radio terminals to access a system, which can provide significant performance gains over the original MIMO technology.
MU-MIMO features prominently in the 2013 update of the 802.11ac wireless specification (802.11ac Wave 2) and helps increase theoretical maximum wireless speeds from 3.47 Gbps to 6.93 Gbps for 802.11ac Wave 2.
MU-MIMO enables multiple users to simultaneously access the same channel by providing spatial degrees of freedom. However, because of its need for sophisticated antenna systems and signal processing, MU-MIMO can only be used in the downstream direction (from an access point to multiple wireless client devices) in the 802.11ac Wave 2 specification.
