Low-complexity DOA estimation method based on co-prime circular array

Abstract

The invention discloses a low-complexity DOA estimation method based on a co-prime circular array. The method is characterized by comprising the following steps of: constructing a cross-covariance matrix according to data received by two sub-arrays; obtaining an enhanced covariance matrix by utilizing the central symmetry of the array element positions of the circular array; utilizing an improvedpropagation operator method to construct projection matrixes which are respectively orthogonal to a direction matrix; constructing spatial spectrums of the two sub-arrays according to the orthogonality of a steering vector and a projection matrix; finally, substituting the spectral peak of one sub-array into the spatial spectrum of the other sub-array, taking angle values corresponding to K valueswith the maximum function value as a group of estimated values, finding every two corresponding closest values from the two groups as a pair (K pairs in total), and averaging the K pairs of values toobtain a final estimated value. According to the novel circular array structure designed by the invention, the array aperture can be effectively increased, the construction of an overall covariance matrix is avoided, the calculation complexity is reduced, and the estimation precision is higher.

Description

technical field [0001] The invention relates to the technical field of wireless direction finding, in particular to a low-complexity DOA estimation method based on a coprime circular array. Background technique [0002] For the Direction of Arrival (DOA) estimation of the circular array, because the steering vector of the circular array does not conform to the Vandermonde form, the DOA estimation method of the traditional linear array cannot be directly applied to the circular array, and the circular array steering vector needs to be converted to Change into Vandermonde form and then estimate direction of arrival. At the same time, the elements of the traditional circular array are evenly and closely arranged on the circle, and the estimation error caused by the mutual coupling effect of adjacent array elements is larger than that of the traditional linear array. Therefore, in order to reduce the mutual coupling effect of the uniform circular array, a sparse circular array i...

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Problems solved by technology

At the same time, the elements of the traditional circular array are evenly and closely arranged on the circle, and the estimation error caused by the mutual coupling effect of adjacent array elements is larger than that of the traditional linear array. Therefore, in order to reduce the mutual coupling effect of the uniform circular array, a sparse circular array is designed structure matters

[0003] The traditional beam switching technology requires that the distance between adjacent array elements is less than half a wavelength, and the distance between adjacent array elements is small, which is prone to mutual coupling effects, and due to the need for eigenvalue decomposition, the complexity is high

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