A High-Resolution Orientation Estimation Method Based on Two-Dimensional Power Distribution for Few Arrays

Abstract

The invention is a method for estimating high-resolution azimuth of a few-element array based on two-dimensional power distribution. The invention acquires the receiving signal of the basic array, performs Kronecker product operation on the receiving signal of the array element; uses the operation result as a new acquisition signal, performs CBF power spectrum, selects the space observation angle interval, and constructs a three-dimensional power spectrum matrix according to the selected observation angle ; According to the CBF power spectrum and the three-dimensional power spectrum matrix obtained in the first step, the two-dimensional power distribution matrix is ​​determined by the compressed sensing method; the maximum value is obtained according to each column of the two-dimensional power distribution matrix, and the result is used as the power spectrum of the new algorithm. Estimated at DOA. The data in the two-dimensional matrix is ​​restricted by two angle sets. While improving the estimation accuracy, it reduces the demand for the number of high-resolution array elements, and effectively improves the estimation accuracy and resolution when there are few array elements.

Description

technical field [0001] The invention relates to the technical field of direction of arrival estimation of underwater acoustic waves, and is a high-resolution azimuth estimation method for a few-array element array based on two-dimensional power distribution. Background technique [0002] Direction of arrival (DOA) estimation is a research hotspot in array signal processing. Its main research content is to obtain exact target azimuth information from noise and interference background. It is used in radar, sonar, navigation, non-destructive testing and wireless communication. Has a wide range of applications. Resolution and side lobe height are important indicators to measure the performance of the DOA estimation algorithm. It is well known that if the beam width is wide, it is difficult to detect two targets in the same beam. If the side lobe height is high, it is difficult to detect in the presence of strong interference. Weak signal. [0003] Generally speaking, the metho...

AI Technical Summary

Problems solved by technology

[0004] The beamforming algorithm is the most traditional DOA estimation method, but it is affected by the Rayleigh limit, and the azimuth resolution is low. The MVDR beamforming method has better spatial resolution and unknown strong interference suppression ability, but its estimation accuracy often decreases. Affected by various error factors such as array element amplitude and phase errors, array element position errors, etc.

[0005] Multiple signal classification method (MUSIC) is the most classic high-resolution estimation algorithm, which has higher resolution than CBF and MVDR, but when the number of snapshots decreases and the signal-to-noise ratio is low, this type of method suffers from severe estimation performance. In the worsening situation, if the number of signals is unclear or the correlation between target signals is strong, it will also cause serious damage to the signal and noise subspaces, thereby further reducing the resolution and estimation accuracy of subspace methods.

In recent years, the deconvolution method has been applied to azimuth estimation and sound source localization, which has effectively improved the disadvantage of poor resolution of the CBF method (RL-dCv), but the RL-dCv algorithm is only suitable for beam response functions with shift-invariant beam response, such as the CBF beam response of a uniform linear array, which greatly narrows the range of use of the algorithm

[0006] Most of the high-resolution algorithms, including the above algorithms, usually require a high SNR environment and a multi-element array to achieve high resolution. Strong environmental noise and a small number of array elements will affect the performance of high-resolution capabilities, but Due to the complexity of the marine environment, there are a large number of various noise sources in the ocean, including marine environmental noise, ship radiation noise, etc., and these noises usually appear randomly and are unpredictable

In addition, many practical conditions do not allow multi-element arrays. For example, small-sized unmanned platforms cannot carry large-scale arrays, or the number of array elements needs to be limited due to limited funds. The DOA algorithm with high resolution ability still needs to be paid attention to

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