Adaptive
Beamfoming.
Quick
Navigation
Introduction:
There are many ways to do beamforming, depending on the particular problem specification. Actually one can use beamforming in domains like:
-
Detection and localization of submarines using sonar and of airplanes using radar waves.
-
Exploration of the underground using microphones to find out the structure of the earth and to detect oil or other minerals.
-
In telecommunication to increase the density of users and the QoS
We can define different types of beamforming depending on what one knows about the sources and the interferences to be suppressed. If the source location as well as the jammers' positions are known, a classic solution is possible, which involves inverting the covariance Matrix of the received signal. If the frequency of the source is different from the interferer's ones, different classic and well-known solutions are available.
Wireless solutions:
Because we'll focus on the cellular phone networks, we can assume that:
-
The location of the different MS (and the Directions of Arrival DOAs) are changing and unknown
-
The carrier frequencies from the different users are the same.(900 and 1800 MHz for the European Networks GSM)
This motivates one to look at adaptive solutions, which update the solution during the journey of the users. Among the types of adaptive solutions, we will examine the capabilities of the Set Membership Filtering (SMF) algorithms and compare them against the conventional ones like gradient based e.g. .