Multiple Input/Multiple Output. A technique that processes the multi-path RF (Radio) signals that are normally a problem for WLAN transmission and uses them to its advantage to deliver better throughput. MIMO will be used to enhance 802.11 throughput in the 802.11n WLAN standard

Multi-path radio signals are a common problem in many radio transmissions. In old styled antenna-based television reception they were responsible for the ghost images often seen on the screen. Sadly, some cable companies pass on multi-path ghosts as well.

Multi-path RF distortion is caused by signals bouncing off of objects (such as skyscrapers) on their way to the receiver from the transmission tower. The signals that bounce off of objects arrive a little later than the direct signals because they take a longer rout. The more objects the arriving signals bounce off of, the more zigzag (and therefore longer) their rout is, making it take longer for them to arrive at the receiver.