Fundamentals of WLAN MIMO

The multiple-input and multiple-output (MIMO) technology is introduced in the IEEE 802.11n protocol and brings the wireless local area network (WLAN) technology into a multi-antenna era. Multiple antennas are used at both the transmit end and the receive end to transmit and receive signals. The MIMO technology reduces error codes and speeds up data transmission to improve service quality.

In a traditional WLAN system, both an AP and a user device use only one antenna. Signals are transmitted through the 802.11a/b/g protocol. The maximum signal transmission rate is 54 Mbit/s and can hardly be increased anymore. With the increasing popularity and application of the WLAN technology, the rate of wireless communication needs to be increased
substantially.

The MIMO technology, which is used in the 802.11n protocol, increases the rate of WLAN signal transmission greatly, and satisfies growing requirements on bandwidth and signal quality.