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.