Research On Robust Beamforming With Limited Snapshot And Guidance Vector Error

Adaptive beamforming is one of the two important branches in the field of array signal processing,which is suitable for interference suppression in the rapidly changing signal environment.Because of its high gain,high resolution and the convenience of beam pattern control,it is widely used in radar,sonar,communication and other military and civil fields.However,in practical applications,many errors will affect the performance of the algorithm,the most common of which are the limited snapshot and the error of the guidance vector,which will lead to a sharp decline in beamforming performance.Therefore,it is very important to improve the robustness of beamforming.In this paper,we study the robust beamforming under the condition of limited snapshot and guidance vector error,The main work is divided into the following three points:(1)Research on robust adaptive beamforming algorithm in the case of limited snapshot.In order to deal with the performance degradation of the algorithm in the case of limited snapshot,this paper studies a robust adaptive beamforming algorithm based on improved weighted spatial smoothing.The algorithm improves the weighted spatial smoothing,uses the special subarray division form to avoid the dependence on the prior information of the array,removes the correlation between the expected signal and the interference plus noise signal in the sample covariance matrix,and uses the guidance vector constraint search signal subspace method to estimate the expected signal guidance vector,so as to obtain the optimal weighted vector of the beamforming.The algorithm effectively guarantees the robustness in the case of limited snapshot.(2)Research on robust adaptive beamforming algorithm in the case of guidance vector error.In order to deal with the problem of algorithm sensitivity in the case of guidance vector error,this paper studies a beamforming algorithm which combines the reconstruction of interference plus noise covariance matrix with the estimation of guidance vector.This algorithm uses the idea of reconstruction of interference plus noise covariance matrix,reduces the integral reconstruction area of the original algorithm,and improves the accuracy of the reconstructed interference plus noise covariance matrix.At the same time,the random error of the guidance vector is modeled by the ring uncertainty set,and the expected signal guidance vector is estimated.The algorithm effectively solves the problem of beamformingperformance sensitivity in the case of guidance vector error.(3)The software of robust adaptive beamforming algorithm based on LabVIEW is designed and developed.Firstly,the parameters in the array model are established by the input control in LabVIEW,then the code program about beamforming in MATLAB is called through the script node of MATLAB,and the result of the program is displayed on the front panel through the XY waveform in LabVIEW.