UAV-Enabled Data Collection for Wireless Sensor Networks With Distributed Beamforming

This paper studies an unmanned aerial vehicle (UAV)-enabled wireless sensor network, in which one UAV flies the sky to collect data transmitted from a set of ground nodes (GNs) via distributed beamforming. We consider two scenarios with delay-tolerant and delay-sensitive applications, GNs send common/shared messages adaptive- fixed-rate transmissions, respectively. For scenarios, we aim maximize average data-rate throughput minimize transmission outage probability, respectively, by jointly optimizing UAV’s trajectory design GNs’ transmit power allocation over time, subject flight speed constraints individual constraints. However, formulated problems are both non-convex thus generally difficult be optimally solved. To tackle this issue, first relaxed ideal case ignored, for well-structured optimal solutions obtained reveal fundamental performance upper bounds. It is shown that approximate problems, have same multi-location-hovering structure, but different strategies. Next, general considered, propose efficient algorithms obtain high-quality using techniques convex optimization approximation. Finally, numerical results show our proposed designs significantly outperform other benchmark schemes, terms achieved probability under scenarios. also observed when mission period becomes sufficiently long, approach bounds ignored.