利用四元阵估计强干扰中弱信号的原理及仿真研究

On Improving the Effectiveness of Estimating Wideband Weak Signals

提出了利用四元阵估计强干扰中弱信号的原理。推导了估计弱信号的一般表达式。理论分析表明 ,只要知道信号波达方向 ,无需其他信号和干扰噪声的信息 ,就可估计强背景干扰噪声中的弱信号。估计信号的精度只与各阵元输出干扰功率之比有关 ,与背景干扰的功率起伏无关 ,因此它比利用三元阵估计信号的方法能更好地适应环境的变化。

We have worked on estimating wideband weak signals for several years and our previous results were given in Refs. [5] and [6], which used three sensor array and lack in effectiveness when strong interference noises fluctuate rapidly with time and space in sea. We now propose using four sensor array to increase its effectiveness. We now add a fourth reference sensor to mitigate the influence of rapid fluctuation of strong interference. Our theoretical analysis shows that such weak signals can be extracted in the absence of information about signal and interference except for the direction of arrival signals. The accuracy of estimated signal is now almost independent of the rapid fluctuation of strong interference power. Simulation results, as given in Fig. 1 and Table 1, show preliminarily that our proposed method is feasible.