Direction of arrival estimation method based on multi-baseline distributed array

Abstract

The invention discloses a direction of arrival estimation method based on a multi-baseline distributed array. The direction of arrival estimation method mainly solves the problem that angles are blurry in the estimation process of a target direction of arrival through an existing distributed array. The implantation process of the direction of arrival estimation method comprises the following steps: subarrays are arranged according to a multi-baseline structure, and received data of the array are extracted; a covariance matrix of the received data is estimated and subjected to eigen decomposition to obtain signal subspaces; a space domain rotational invariance equation in each subarray, a space domain rotational invariance equation between the shortest baseline subarrays, and a space domain rotational invariance equation between the longest baseline subarrays are constructed respectively according to the signal subspaces; the equations are solved respectively to obtain a rough estimation without a blur, a precise estimation with a blur of short baselines and a precise estimation with a blur of long baselines; obtained estimation parameters are subjected to matching and deblurring to obtain the target direction of arrival. By means of the direction of arrival estimation method based on the multi-baseline distributed array, the direction of arrival estimation performance of the distributed array under a low signal to noise ratio condition is improved, the physical aperture of the array is further enlarged, and the direction of arrival estimation method can be applied to target identification.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, relates to a distributed radar angle measurement method, and can be used for target positioning. Background technique [0002] Direction of arrival estimation is an important research field in array signal processing, and has been widely used and studied in radar, wireless communication, sonar and other fields. The physical aperture of the array is an important parameter closely related to the performance of array DOA estimation. The larger the array's physical aperture, the higher the array's angular resolution and DOA estimation accuracy. In order to improve the angular resolution of the array and the estimation accuracy of the direction of arrival, it is necessary to expand the physical aperture of the array, and the most common method is to increase the number of array elements. However, increasing the number of array elements will lead to an increase in the system hardware c...

AI Technical Summary

Problems solved by technology

This method can be applied to multi-target positioning with high positioning accuracy, but the performance of DOA estimation drops significantly under the condition of low signal-to-noise ratio, which greatly limits the expansion of the physical aperture of the distributed array.

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