Two-dimensional direction of arrival estimation method for nested array based L-shaped antenna array

Abstract

The invention discloses a two-dimensional direction of arrival estimation method for a nested array based L-shaped antenna array, and belongs to the field of array signal processing. The implementation method includes the following steps: constructing a nested array based L-shaped antenna array, calculating a cross-covariance matrix by using signals received by different sub arrays of the constructed L-shaped nested array; correcting the obtained cross-covariance matrix, performing vectorization on the corrected cross-covariance matrix to generate a virtual array, constructing a plurality of equivalent covariance matrices by using the virtual array, calculating the signal azimuth angle Theta and the pitch angle Phi by using the rotation invariance between different equivalent covariance matrices, and achieving multi-target and high-precision two-dimensional direction of arrival estimation with few snapshots at a low signal-to-noise ratio. The technical problem to be solved by the invention is to realize multi-target and high-precision two-dimensional direction of arrival estimation by using fewer array elements at a low signal-to-noise ratio and with few snapshots, and to solve related engineering technical problems by using two-dimensional direction of arrival estimation results.

Description

technical field [0001] The invention relates to a two-dimensional direction-of-arrival estimation method based on an L-shaped antenna array of a nested array, belonging to the field of array signal processing. Background technique [0002] The radio direction finding technology is based on the propagation characteristics of the electromagnetic field, and obtains the radio incoming wave direction through certain detection instruments. The direction of arrival estimation is based on the array signal processing method. Multiple sensors are arranged in space to form a sensor array in a certain way, and the airspace characteristics of the array received signals are used to enhance the signal and effectively extract the signal airspace information to achieve radio direction finding. It is widely used at present. It is used in various military and civilian fields such as radar, sonar, wireless communication, etc. [0003] In recent years, two-dimensional direction of arrival estim...

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Problems solved by technology

[0005] The commonly used subspace decomposition algorithms with higher resolution for DOA estimation, such as the multiple signal classification algorithm (MUSIC) and the rotation invariant subspace algorithm (ESPRIT), all need to perform eigenvalue decomposition on the covariance matrix of the signal. According to the size of the eigenvalues, the signal subspace and the noise subspace are divided, and the estimation accuracy is greatly affected by the signal-to-noise ratio, and the estimation accuracy is poor in a low signal-to-noise ratio environment.

In the actual process, the signal covariance matrix is ​​replaced by the sampling covariance matrix. When the number of snapshots is small, subspace leakage is prone to occur, which affects the direction of arrival estimation.

Therefore, the estimation accuracy of the traditional direction of arrival estimation method is poor in the case of low signal-to-noise ratio and few snapshots

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