AirBeam: Experimental Demonstration of Distributed Beamforming by a Swarm of UAVs


Mohanti S., Bocanegra C., Meyer J., Seçinti G. , Diddi M., Singh H., ...More

16th IEEE International Conference on Mobile Ad Hoc and Smart Systems (IEEE MASS), Monterrey, Mexico, 4 - 07 November 2019, pp.162-170 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume:
  • Doi Number: 10.1109/mass.2019.00028
  • City: Monterrey
  • Country: Mexico
  • Page Numbers: pp.162-170
  • Keywords: Unmanned Aerial Vehicle, Distributed beamforming, Software Defined Radio, FPGA

Abstract

We propose AirBeam, the first complete algorithmic framework and systems implementation of distributed air-to-ground beamforming on a fleet of UAVs. AirBeam synchronizes software defined radios (SDRs) mounted on each UAV and assigns beamforming weights to ensure high levels of directivity. We show through an exhaustive set of the experimental studies on UAVs why this problem is difficult given the continuous hovering-related fluctuations, the need to ensure timely feedback from the ground receiver due to the channel coherence time, and the size, weight, power and cost (SWaP-C) constraints for UAVs. AirBeam addresses these challenges through: (i) a channel state estimation method using Gold sequences that is used for setting the suitable beamforming weights, (ii) adaptively starting transmission to synchronize the action of the distributed radios, (iii) a channel state feedback process that exploits statistical knowledge of hovering characteristics. Finally, AirBeam provides insights from a systems integration viewpoint, with reconfigurable B210 SDRs mounted on a fleet of DJI M100 UAVs, using GnuRadio running on an embedded computing host.