Linear constraint virtual antenna beam forming method

Abstract

The invention discloses a linear constraint virtual antenna beam forming method. The method comprises the following steps: to begin with, carrying out pre-estimation on rough orientations of M interferences reaching an array antenna; determining a transformation region theta, and carrying out interpolation transformation according to manifold relationship of an actual array and a virtual array to obtain a transformation matrix; obtaining a covariance matrix of the virtual array by utilizing the transformation matrix; carrying out forward-backward spatial smoothing treatment on the covariance matrix of the virtual array; constructing a correlation matrix of steering vectors in an interpolation transformation region, extracting feature vectors corresponding to larger characteristic values in the correlation matrix and carrying out linear zero-setting constraint on the extracted feature vectors; and calculating the optimal weight vector and forming a wave beam. The method can greatly deepen nulling depth of the wave beam formed by the virtual array, reduce side lobe level, improve output SINR(signal to interference plus noise ratio), effectively suppress interference of super array freedom degree and improve anti-interference performance of the virtual antenna array.

Description

technical field [0001] The invention belongs to the control field of adaptive array antennas, in particular to a linear constrained virtual antenna beam forming method with strong anti-interference ability. Background technique [0002] With the development of electronic information technology, the electromagnetic environment is becoming more and more complex, and electromagnetic interference is becoming more and more serious, especially in some electronic warfare occasions, the amount of interference that needs to be suppressed is large, which requires the addition of antennas The number of units, but in many application environments, limited by practical factors, the size of the antenna array cannot be made very large. Therefore, it is hoped that the number of antennas in a limited space can be reduced, and the matrix size of the antenna array can be reduced while resisting a large number of interferences. The virtual array antenna technology is produced under this situat...

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Problems solved by technology

In the literature (Wenxing Li, Yipeng Li, Wenhua Yu. On adaptive beamforming for coherent interference suppression via virtual antenna array [J]. Progress in Electromagnetics Research-PIER, 2012, 125:165-184), the use of interference subspace projection was studied. method to improve the performance of the virtual array to suppress coherent interference, but this method needs to accurately know the incoming wave direction of each interference, which is difficult to achieve in practical applications

[0004] Although the conventional virtual array beam can increase the array degree of freedom, due to the transformation error, the formed beam has a shallow null depth and a low output signal-to-interference-noise ratio (SINR). The side lobe level rises, and even the null shift occurs, and the output performance of the array cannot meet the system requirements

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