Trajectory optimization method for the UAV relaying broadcast communication system

In order to improve the connectivity of the fixed-wing unmanned aerial vehicle(UAV) relaying broadcast communication system, a UAV trajectory optimization method is proposed. First, the approximate expression for the outage probability for a single user node in the UAV broadcast communication system is obtained. Based on this, the approximate calculation formula for the average outage probability for all user nodes in the service area is deduced. Then, the trajectory optimization method is given based on the criterion of minimizing the average outage probability of all user nodes in the service area. Next, the exact mathematical expression for outage probability for the single user node is derived to evaluate the system performance. Finally, the validity of the proposed scheme is proved by computer simulation.