Peak Age-of-Information Minimization of UAV-Aided Relay Transmission

We consider a scenario where an unmanned aerial vehicle (UAV) aids a source node to transmit data packets to a remote destination node. The goal is to minimize the peak age-of-information (PAoI) by jointly optimizing the flight trajectory of the UAV, the service time of data packets, and the power allocation for packet transmission. The feasibility condition of the joint design problem is first derived. Since the joint design problem is highly non-convex, we propose an efficient iterative algorithm based on the successive convex approximation to transform this non-convex problem into convex optimization problems, which can thus be efficiently solved by the off-the-shelf solvers. The simulation results show that the proposed algorithm performs better than that based on the alternating optimization. The energy and power constraints have a significant impact on the PAoI. Meanwhile, when the energy is limited and/or the packet loads are heavy, the PAoI is dominated by the flight time of the UAV.