Principle and simulation of coherent interference suppression by a three-sensor array

Principles of coherent interference suppression are presented by a three-sensor array in this paper. The formulae of extracting expected signals from strong interference are derived. The selection of sensor distance is discussed and then relationships between the distance and frequency point, at which the signals can be extracted, are given. When expected signals are band-limit, the conditions of the selected sensor distance, which should be satisfied, are given. Last, performance of interference suppression is analyzed when the amplitude of interference power spectra of signals received by three sensors fluctuates, and the expressions of relative error of the extracted signals and processing gain are derived.The theoretical and simulation results show that signals can be extracted from strong background interference without any information about signals and interference expect for the arriving direction of signals, that the distance between sensors should be smaller than half wave length of upper limit frequency when the expected signals are band-limit, and that performance of extracting signals will decline with the increase of fluctuation of interference spectrum amplitude.