736 research outputs found
Adaptive Scheduling and Trajectory Design for Power-Constrained Wireless UAV Relays
This paper investigates the adaptive trajectory and communication scheduling
design for an unmanned aerial vehicle (UAV) relaying random data traffic
generated by ground nodes to a base station. The goal is to minimize the
expected average communication delay to serve requests, subject to an average
UAV mobility power constraint. It is shown that the problem can be cast as a
semi-Markov decision process with a two-scale structure, which is optimized
efficiently: in the outer decision, the UAV radial velocity for waiting phases
and end radius for communication phases optimize the average long-term
delay-power trade-off; given outer decisions, inner decisions greedily minimize
the instantaneous delay-power cost, yielding the optimal angular velocity in
waiting states, and the optimal relay strategy and UAV trajectory in
communication states. A constrained particle swarm optimization algorithm is
designed to optimize these trajectory problems, demonstrating 100x faster
computational speeds than successive convex approximation methods. Simulations
demonstrate that an intelligent adaptive design exploiting realistic UAV
mobility features, such as helicopter translational lift, reduces the average
communication delay and UAV mobility power consumption by 44% and 7%,
respectively, with respect to an optimal hovering strategy and by 2% and 13%,
respectively, with respect to a greedy delay minimization scheme.Comment: Submitted to IEEE Transactions on Wireless Communication
- …