Effect of Element Mutual Coupling on the Performance of Adaptive Arrays

摘要

Adaptive arrays are highly versatile sensors employed in modern wireless communication systems to combat interference and multi-path fading and thereby increase system capacity. In adaptive processing, weights are attached to the incoming signal at each element to produce nulls in the directions of interferers. However, mutual coupling is normally ignored in such processing. Instead, the principle of pattern multiplication is used, where the assumption is that the radiation pattern of an array is the individual radiation pattern of the elements multiplied by an array factor. This assumption ignores mutual couplings and the error can be significant under certain conditions. This work begins by setting up the scenario of an adaptive array in a mobile communications scenario in a scattering environment. Following that, we introduce the theories of mutual couplings and beam-forming.