一种减小互耦的互素嵌套阵列及测向算法

为了减小阵元之间的互耦效应,首先提出一种阵元间距可调节的互素嵌套阵列.这种阵列由2个不同的嵌套子阵列组成,2个子阵的最小阵元间距由一对互素的正整数确定.只要这对正整数足够大,2个子阵的最小阵元间距便可远超过入射信号的半个波长,从而将阵元间的互耦效应减小到可忽略的程度.然后,为了解决大间距阵列所引起的角度模糊问题,提出了一种基于四阶累积量的无模糊波达方向(DOA,direction of arrival)估计算法.仿真实验表明,此算法具有较好的估计性能,相比一些经典的自校正DOA估计算法,此算法具有更高的角度分辨力和估计精确度.

A co-prime nested array algorithm in reducing mutual coupling and DOA estimation

In order to reduce the mutual coupling between sensors, a kind of co-prime nested array with adjustable element spacing is proposed. The proposed array consists of two nested arrays with different element spacing and the smallest intervals of two sub-arrays are determined by two co-prime positive integers. As long as the positive integers are big enough, the smallest intervals of each sub-array can be far more than half the wave length of incident signal, hence the reduction of the mutual coupling effect between sensors to a negligible level. To eliminate the direction ambiguity caused by large element spacing, a direction of arrival (DOA) estimation algorithm based on fourth-order cumulants is proposed to get unambiguous direction estimation. Compared with some classical self-correcting methods, the proposed algorithm has a higher angle resolution and estimation precision. Simulation results have proved the improved performance of proposed algorithm.