A Robust Beamforming Algorithm for Null Broadening Based on Covariance Matrix Reconstruction and Virtual Antenna Technology

When the sidelobe interference perturbation or the array platform vibration happen to adaptive antenna array, the sidelobe interference overflows the null, resulting in the degradation of the output performance of the adaptive beamformer. To solve this problem, we propose a null broadening algorithm based on covariance matrix reconstruction and virtual antenna technology in this paper. According to eigenvector correlation we reconstruct a sidelobe interference plus noise covariance matrix. Then we construct a projection transformation matrix using the interference steering vector and the reconstructed interference plus noise covariance matrix is processed. Finally, the covariance matrix is extended and adaptive beamforming is carried out combined with virtual antenna technology. Simulation results show that the null broadening algorithm can effectively suppress interferences and has good robustness.