An Efficient Broadband Adaptive Beamforming Algorithm Based on Frequency-Space Cascade Processing

摘要

In this paper, the performance loss caused by the aperture fill phenomena and heavy computational burden in broadband adaptive beamforming (ADBF) is analyzed, and an efficient approach based on frequency-space cascade processing is presented. First, a digital compensation method is applied to compensate for the aperture fill time of the broadband phased array in the range-frequency domain, removing the dependence of the wideband array steering vector on the instantaneous frequency. Second, a subband adaptive beamforming scheme using range-compressed data is implemented, reducing the degrees of freedom of wideband jamming and avoiding signal cancelation in the ADBF covariance matrix estimation. Moreover, the conjugate gradient algorithm is used to iteratively calculate the ADBF weight vector to reduce the computational complexity. Finally, wideband ADBF can be achieved by subband synthesis. Theoretical analysis and simulation results are provided to demonstrate that the proposed approach can suppress jamming sufficiently with a rapid convergence rate, making this approach feasible for engineering implementation.