基于ESPRIT的多基线分布式阵列DOA估计方法

为了提高分布式阵列在低信噪比（signal-to-noise ratio, SNR）条件下的波达方向(direction-of-arrival， DOA)估计性能，同时放宽阵列物理孔径扩展程度的限制，提出了一种基于旋转不变子空间（estimation of signal parameters via rotational invariance techniques， ESPRIT）的多基线分布式阵列DOA估计方法。该方法通过优化分布式阵列结构，在子阵间使用多基线结构布阵，结合ESPRIT算法和多步解模糊方法得到多基线分布式阵列的高精度无模糊DOA估计。此外，利用最大后验概率准则近似法分析分布式阵列DOA估计的门限效应，给出了SNR门限和基线长度门限的近似计算方法。计算机仿真结果验证了所提方法的有效性。

Multi-baseline distributed array DOA estimation using ESPRIT algorithm

In order to improve the accuracy of direction-of-arrival (DOA) estimation with distributed arrays in a low signal-to-noise ratio （SNR） scenario, and to loosen the restrictions on array aperture extension, a DOA estimation method based on estimation of signal parameters via rotational invariance techniques (ESPRIT) is proposed for multi-baseline distributed arrays. The configuration of the distributed array is firstly optimized to obtain multi baseline subarrays. Then high accuracy and unambiguous DOA estimates are obtained by the combination of ESPRIT algorithm and the multi-step disambiguation method. Moreover, the threshold effect on the DOA estimation method is analyzed via the maximum a posteriori criterion. Furthermore, approximate methods for SNR threshold and baseline threshold calculations are presented. Finally, simulation results are given to verify the effectiveness of the proposed method.