Optimization Method of Sparse Array Frequency and Steering Invariant Beamforming

The conventional beamforming optimization method cannot meet the requirements of constant beamwidth of spare array in different frequency and different beam pointing angles. In this paper, a frequency and steering invariant beamforming method based on compressed sensing (CSFSIB) is proposed. First, the array elements are extended virtually, the sparse signal obtained by virtual array is reconstructed by compressed sensing (CS) recovery algorithm. Then the Second-order cone programming (SOCP) method is used to calculate the weighted vector and optimize the steering invariant beamforming (SIB). Finally, frequency invariant beamforming (FIB) is designed based on inverse Fourier transform (IFT). Simulation results indicate that the proposed method can reduce the sidelobe level and save the number of array elements while keeping the mainlobe width constant.