Optimal Trajectory Planning for UAV-relayed Dynamic Spectrum Access

摘要

Unmanned aerial vehicle (UAV) has greatly extended the scope of wireless broadband access by serving as a relay between the base station and user devices. In the paradigm of dynamic spectrum access (DSA), a UAV needs to traverse the flight area without interfering with incumbent users, and takes tune to serve the secondary users in the user area. It is important to minimize the service period by planning the UAV's trajectory. In this paper, we study the trajectory planning problem of optimizing the flight route of the UAV, given the incumbent protection zone where the UAV cannot enter, for DSA. We divide the user area and the flight area into multiple 2D grids. Then, we formulate the problem as finding the optimal trajectory in the flight area to cover the user area. We propose an algorithm that first finds the trajectory in each divided 2D grid by generating the minimum dominating path and selecting necessary critical flight locations within the path, and then concatenates the obtained trajectories to the trajectory in the flight area. Experimental results show that the UAV takes 32% less time to finish trajectory under proposed algorithm, and as the user area and the flight area become larger, the gap among algorithms increases.