UAV-Enabled Uplink in Massive IoT Networks with Circular and Spiral Trajectory Designs

This work is on the uplink of a massive Internet-of-Things (IoT) network where an unmanned aerial vehicle (UAV) base station (BS) receives signals from ground users independently and uniformly distributed in a disk region. Aiming at low complexity schemes and analytical results, we consider the circular and spiral UAV trajectories. For the circular trajectory, we propose a low-complexity angle-based user scheduling scheme and show that it achieves the optimal asymptotic user rate as the number of users grows to infinity. A closed-form expression of the optimal asymptotic user rate is also derived. Further, an analytical Archimedean spiral trajectory model is proposed, and a low-complexity group-and-match user scheduling scheme is developed. Numerical evidence is provided for the proposed scheduling schemes and derivations.