Distributed Transmit Beamforming with Autonomous and Self-Organizing Mobile Antennas

The paper studies the problem of distributed transmit beamforming with autonomous and self-organizing mobile antennas. The objective is to design a distributed algorithm for a network of autonomous mobile robots with carry-on antennas so that they can form a functional antenna array and cooperatively transmit messages to a remote station. Note that the spatial relationship of the antennas also contributes to the directionality of the reception or transmission of a signal. In the paper, by exploiting the mobility of the antennas, we show that optimal beamforming can be achieved by reconfiguring the spatial relationship of the mobile antennas in a completely distributed fashion. A probability-based coordination scheme utilizing only the signal-to-ratio (SNR) feedback from the receiver is presented to update the positions of the antennas ensuring that they eventually converge to a global optimal configuration maximizing the SNR at the receiver. It is noticed that the spatial configuration of the antennas can also address the phase synchronization issue in transmit beamforming.