MIMO Technology for Advanced Wireless Local Area Networks


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Wireless LAN Technology Advances



How can this growth continue?
Previous advances have been limited to a single transmitting and receiving radio
The next generation exploits multiple parallel radios using revolutionary class of techniques called MIMO (Multiple Input Multiple Output) to send information farther and faster


Wireless Fundamentals I

In order to successfully decode data, signal strength needs to be greater than noise + interference by a certain amount
Higher data rates require higher SINR (Signal to Noise and Interference Ratio)
Signal strength decreases with increased range in a wireless environment


Wireless Fundamentals II
Ways to increase data rate:
Conventional single tx and rx radio systems
Increase transmit power
Subject to power amplifier and regulatory limits
Increases interference to other devices
Reduces battery life
Use high gain directional antennas
Fixed direction(s) limit coverage to given sector(s)
Use more frequency spectrum
Subject to FCC / regulatory domain constraints
Advanced MIMO: Use multiple tx and / or rx radios!

MIMO Wireless Systems

Multiple Input Multiple Output (MIMO) systems with multiple parallel radios improve the following:

Outages reduced by using information from multiple antennas
Transmit power can be increased via multiple power amplifiers
Higher throughputs possible
Transmit and receive interference limited by some techniques