WHAT IS MIMO?

Multiple Input Multiple Output (MIMO) is a smart antenna technique that increases speed, range, reliability and spectral efficiency for wireless systems. MIMO is a new wireless technology conceived in the mid 90’s A technique for boosting wireless bandwidth and range by taking advantage of multiplexing. It is based on an entirely new paradigm for digital signal processing that multiplies the data rate throughput achievable in wireless communication products. Greatly improves the reliability, range and robustness of the connection providing a much better user experience that is closer to “wired” Ethernet quality.

MIMO is one technology being considered for 802.11n, a standard for next-generation 802.11 that boosts throughput to 100M bit/sec. In the meantime, proprietary MIMO technology improves performance of existing 802.11a/b/g networks.

During the 1990s, Stanford University researchers Greg Raleigh and VK Jones showed that a characteristic of radio transmission called multipath, which had previously been considered an impairment to radio transmission, is actually a gift of nature. Multipath occurs when signals sent from a transmitter reflect off objects in the environment and take multiple paths to the receiver. The researchers showed that multipath can be exploited to multiplicatively increase the capacity of a radio system.

If each multipath route could be treated as a separate channel, it would be as if each route were a separate virtual wire. A channel with multipath then would be like a bundle of virtual wires. MIMO uses multiple, spatially separated antennas. MIMO encodes a high-speed datastream across multiple antennas. Each antenna carries a separate, lower-speed stream. Multipath virtual wires are utilized to send the lower-speed streams simultaneously.