Coherent signals adaptive beamforming algorithm based on eigenvalue

Aiming at the problem of beamformer performance degradation caused by coherent signals, We propose an adaptive beamforming algorithm for interference plus noise covariance matrix (INCM) reconstruction. The idea of the proposed algorithm is that the sum of eigenvalues (SE) is not affected by coherent signals, so that the power of the eigenvalues can be used to reconstruct INCM. First, we perform eigenvalue decomposition on the covariance matrix after the forward and backward spatial smoothing, which proves that spatial smoothing does not affect SE. On this basis, a new method of signal power estimation is proposed. The estimated signal power and direction vector are then used to reconstruct INCM. Finally, the weight vector is calculated from the estimated desired signal steering vector (DSDV) and the reconstructed INCM. The innovation of this algorithm lies in the combination of coherent signal processing and beamforming, which effectively improves the output interference plus noise ratio (SINR) performance of the beamformer. Simulation analysis verifies the superiority of the algorithm and the validity of theoretical analysis.