DOA (direction of arrival) estimation method based on nested minimum redundant array

Abstract

The invention discloses a DOA (direction of arrival) estimation method based on a nested minimum redundant array, and mainly solves the problem of low DOA estimation resolution when the number of targets is greater than the number of array elements in the prior art. An implementation process of the method comprises the following steps: 1, giving a total array element number to built a nested minimum redundant array (NMRA), 2, obtaining received data X(t) of the NMRA according to the NMRA, 3, estimating a covariance matrix R<XX> of the NMRA according to the X(t), vectorizing the R<XX>, removing repeated elements, and then obtaining differential synthesis array received data Z<c>, 4, dividing Z<c> into a plurality of sub array received data, calculating a covariance matrix of each sub array received data, performing forward and backward smooth average, and then obtaining rank recovery data covariance matrix R<SS>, and 5, performing eigenvalue decomposition on the R<SS>, and then obtaining a DOA estimation angle. The method has the advantages of the large aperture, the high degree of freedom and good DOA estimation angle measurement performance in the same condition, and can be applied to radar target signal detection or power estimation.

Description

[0001] The invention belongs to the technical field of signal processing, and in particular relates to a nested minimum redundant array structure, which is used for estimating the direction of arrival when the number of targets is greater than the number of array elements, and improving the accuracy of angle measurement. Background technique [0002] Direction of Arrival (DOA) estimation is an important research direction in radar and sonar signal processing. As we all know, for a uniform linear array with N array elements, the maximum number of targets that can be resolved by traditional DOA estimation methods, such as MUSIC and ESPRIT, is N-1. The problem of underdetermined DOA estimation, that is, DOA estimation where the number of targets is greater than the number of array elements, often appears and arouses extensive research interest. One of the effective ways to solve this problem is to use an equivalent virtual array to improve the DOA estimation degree of freedom, wh...

AI Technical Summary

Problems solved by technology

However, since the estimation algorithm based on spatial smoothing is generally only suitable for uniform linear arrays, DOA estimation can only use a part of the virtual array constructed by the coprime array, which will reduce the degree of freedom and the array aperture.

[0004] In summary, although the existing arrays can obtain more degrees of freedom than the number of array elements, they all have certain limitations, so it is necessary to design a new array with better comprehensive performance

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