利用三元阵的相干干扰抵消原理及仿真研究

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

介绍了利用三元传感器阵抵消相干干扰的原理。推导了从强干扰中提取期望信号的表达式；讨论了阵元间距的选择，给出了阵元间距与出现方程无解的频率点之间的关系，给出了当期望信号是带限信号时的阵元间距应满足的条件；最后分析了干扰频谱幅度起伏对抵消干扰性能的影响，推导了提取期望信号的相对误差及阵处理增益的表达式．理论分析及仿真结果表明：只要知道信号的到达方向，无需知道干扰的其他信息，就可以从强干扰中提取弱信号；阵元间距必须小于信号上限频率对应的半波长；抵消干扰的性能随干扰谱幅度起伏的增大而下降。

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.