One-bit feedback algorithm with decreasing step size for distributed beamforming

An iterative algorithm with a decreasing step size is proposed for distributed transmit beamforming to achieve carrier phase alignment at the receiver. The transmitters apply random perturbations on their phase offsets and adjust them based on one bit feedback from the receiver in each iteration. The perturbation step size becomes smaller when the phase angles at the receiver get closer to coherence. The step size is decreased by a specified ratio every time the number of successive failed perturbations surpasses a certain threshold. The proposed algorithm has an improvement in the convergence speed of phase alignment compared to the original iterative algorithm in the literature which has a fixed step size during the convergence process.