1. Introduction
Adaptive beamforming [1], [2] is capable of separating signals transmitted in the same frequency band, provided that they arrive from different angles, i.e. they are separated in the spatial domain. This facilitates the separation of the desired signal from the interfering signals. The beamforming process appropriately combines the signals received by the different elements of an antenna array in order to form a single output. An adaptive antenna array is capable of optimising the beamforming pattern by adjusting the array weights such that the specific objective function used – for example the Signal-to-Interference plus Noise Ratio (SINR) is optimised. The specific choice of the adaptive beamforming algorithm determines the speed of convergence, the hardware complexity required for implementing the algorithm and the overall performance of a system.