Direction of Arrival Estimation Method Based on Nested Subarray Array

Abstract

The invention discloses a direction-of-arrival estimation method based on a nested subarray array, and mainly solves the problem existing in the prior art that the degree of freedom, array aperture and array density are not high. The realization process includes the steps of: 1. giving the total number of array elements, and determining the number of subarrays and the number of array elements in each subarray; 2. selecting a uniform linear array or minimum redundancy array or nested linear array structure according to the number of array elements in each subarray; 3. selecting a uniform linear array or minimum redundancy array or nested linear array structure according to the number of the subarrays; 4. constructing a nested subarray array according to a selected array element structure in each subarray and subarray structure; 5. obtaining received data X(t) according to the nested subarray array; 6. obtaining differential synthesis array received data zc according to X(t), and then obtaining a rank recovery data covariance matrix RSS; and 7. decomposing characteristic values of the RSS to obtain a direction-of-arrival estimation angle. The direction-of-arrival estimation method provided by the invention has the advantages of flexible array configuration and good direction-of-arrival estimation angle measurement performance under the same conditions, and can be used for 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 non-equidistant linear array configuration method, 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 degree of freedom, angle measurement accuracy and density of the array. Background technique [0002] Direction of Arrival (DOA) estimation is an important research direction in radar and sonar signal processing. For a uniform linear array with S array elements, the maximum number of targets that can be resolved by traditional DOA estimation methods such as MUSIC and ESPRIT is S-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. An effective way to solve this problem is to improve the DOF of direction of arrival estimation by using ...

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.

[0005] However, even if the array structure has a high degree of freedom and array aperture, the issue of array density must also be considered. A lower array density will cause limited transmission power, which is undesirable in actual engineering

[0006] 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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