Robust and fast beamforming with magnitude response constraints for multiple-input multiple-output radar

In this study, a new robust and fast beamformer is developed for multiple-input multiple-output radar to improve the robustness against steering vector (SV) mismatches. A convex robust model with magnitude response constraints (MRC) is established by using the conjugate symmetry characteristic of the transmitted-received SV. To reduce the computational complexity and the number of samples required, the full-dimensional weight vector (WV) is expressed as the Kronecker product of the transmitted and received array WVs. Thus, the convex problem is converted into a bi-quadratic cost function and it is solved by combining the bi-iterative algorithm and convex quadratic program. The proposed beamformer can flexibly control the beamwidth of the robust region and achieve high output signal-to-interference-plus-noise ratio. Moreover, the proposed method has lower computational complexity and faster sample convergence rate as compared with the traditional MRC-iterative second-order cone programming and MRC-semi-definite programming beamformers. Finally, numerical simulations are provided to demonstrate the effectiveness and robustness of the proposed beamformer.