Smart Antenna System—Beamforming
There is an ever-increasing demand on mobile wireless operators to provide voice and high-speed data services.
At the same time, these operators want to support more users per basestation to reduce overall network costs and make the services affordable to subscribers.
As a result, wireless systems that enable higher data rates and higher capacities are a pressing need.
Interference Limited Systems
Unfortunately, because the available broadcast spectrum is limited, attempts to increase traffic within a fixed bandwidth create more interference in the system and degrade the signal quality.
"Smart Antenna Technology—Beamforming"
Smart antenna technology offers a significantly improved solution to reduce interference levels and improve the system capacity. With this technology, each user’s signal is transmitted and received by the basestation only in the direction of that particular user. This drastically reduces the overall interference in the system.
A smart antenna system, consists of an array of antennas that together direct different transmission/reception beams toward each user in the system. This method of transmission and reception is called "Beamforming" and is made possible through smart (advanced) signal processing at the baseband.
In beamforming, each user’s signal is multiplied with complex weights that adjust the magnitude and phase of the signal to and from each antenna.
This causes the output from the array of antennas to form a transmit/receive beam in the desired direction and minimizes the output in other directions.