Data synchronization for throughput maximization in distributed transmit beamforming

In distributed transmit beamforming, two, or more, spatially separated communications nodes act as elements of an antenna array to beamform common data to a destination node. Spatially separated cooperating nodes synchronize their carrier frequencies and control their transmission phases so that at the destination node the received signals combine constructively. An important example is cooperative communications from a cluster of small satellites to a ground station. The focus of this paper is on optimizing the number of packets that each cooperative node should send to others during each data sharing time interval in order to maximize the data throughput during distributed transmit beamforming stage. The problem is formulated as an optimization problem and a novel heuristic method is proposed to obtain the optimum solutions, as an alternative to the exhaustive search with high computational complexity. Simulation results show that the proposed heuristic method has excellent performance compared to the exhaustive search but with very low computational complexity.