Time-domain frequency-invariant beampattern synthesis via alternating direction method of multipliers

This paper addresses time-domain frequency-invariant beampattern synthesis under multiple constraints. Mainlobe spatial response variation is introduced to characterize the frequency invariance. Peak constraints and norm constraints are imposed to control the sidelobe response and robustness of the beamformer, respectively. Such constraints are separated with the help of the alternating direction method of multipliers (ADMM), and an iterative solution is derived. Unlike the traditional interior-point approach with cubic complexity, the proposed algorithm shows quadratic complexity in a single iteration. Simulation results demonstrate that the proposed algorithm can achieve satisfactory performance in less time.