互质阵列下基于重叠有效孔径的DOA估计算法

DOA estimation algorithm based on overlapped coarray aperture under coprime array

摘要:

为了解决互质阵列下DOA（Direction of Arrival）估计算法因使用空间平滑预处理而带来的阵列有效孔径损失、分辨率降低等问题,提出了一种矩阵重叠预处理方法. 该方法通过分割空间平滑协方差矩阵,利用其子矩阵具有相同信号子空间的特性,将子矩阵进行重叠处理,扩展协方差矩阵行数,进而增大有效孔径. 仿真实验结果表明:所提方法可以提高DOA估计的分辨率,低快拍下的估计精确度也有所提高. 同时,本文将U-ESPRIT（Unitary Estimation of Signal Parameter via Rotational Invariance Techniques）算法应用在互质阵列上,通过使用矩阵重叠预处理并结合U-ESPRIT算法,取得了较传统方法更为准确的DOA估计效果.

Abstract:

In order to solve the problem of the effective aperture loss and resolution reduction of the direction of arrival (DOA) estimation algorithm under the coprime array due to the use of spatial smoothing preprocessing, a matrix with overlapped and augmented coarray preprocessing method is proposed. The principle of this method is to split the spatial smoothing covariance matrix and make use of the characteristic of its submatrices of having the same signal subspace. Overlap processing was applied to submatrices and the number of rows of the covariance matrix was expanded, thereby increasing the effective aperture. The simulation results validated that the proposed method can improve the resolution of the DOA estimation, and the accuracy of the estimation is also improved at low snapshots. At the same time, Unitary Estimation of Signal Parameter via Rotational Invariance Techniques (U-ESPRIT) algorithm was applied to the coprime array. By using matrix overlap preprocessing and combining U-ESPRIT algorithm, the DOA estimation result is more accurate than traditional methods.