基于稀疏互质L型阵列的二维测向算法

Two-dimentional direction finding using a sparse coprime L-sharped array

在阵元数确定的情况下,稀疏阵列能增大阵列孔径,提高测向精度,但也带来测向模糊。针对这个问题,提出了一种稀疏互质L型阵列及其二维测向算法。利用四阶累积量的阵列扩展特性,并结合L型阵列中阵元间距的互质关系,在稀疏阵列结构下实现无模糊二维测向。与二维虚拟旋转不变算法相比,所提算法允许参考阵元间距大于信号半波长,从而提高了测向精度,同时利用逐步解模糊,保证较大的系统容差。计算机仿真结果验证了算法的有效性。

The sparse array with determined elements can increase the array aperture to improve two-dimentional direction-of-arrival （2D-DOA）accuracy, but it brings direction finding ambiguity too. To solve this problem, A sparse coprime L- shaped array and two-dimensional direction finding algorithm based on it are presented. The proposed algorithm utilizes the array extending capability of fourth-order cumulant and the coprime relationship between the interelement spacings in L- shaped array so that 2D-DOA without ambiguity can be realized under sparse array structure. Compared with two-dimentional virtual-ESPRIT algorithm, the proposed algorithm allows the spacings between the reference elements more than one-half wavelength,which leads to improve directi＇on finding accuracy. Meanwhile, the larger system tolerance is guaranteed by a step-by-step reduction of the number of ambiguities. Computer simulation results verify the effectiveness of the proposed algorithm.