Interference-Aware Trajectory Optimization for Cellular-connected UAVs with Obstacle Avoidance

ABSTRACTIn this paper, the problem of finding the optimal trajectory for a cellular-connected unmanned aerial vehicle (UAV), in a 3D environment with obstacles is studied. In particular, the UAV flies from an initial point to a destination point and must maintain a good connectivity with the ground cellular network. Moreover, the resulting trajectory should minimize the emerging interference signals that the ground base stations (GBSs) receive from the UAV. To solve this problem, a probabilistic roadmap (PRM) is constructed first to generate the practical graph for traveling through the area of interest and avoid all type of obstacles. The resulting collision-free interference-aware roadmap illustrates the possible collision-free cellular-connected paths, where the UAV is guaranteed to have a good connectivity with the network, and their corresponding ground interference levels. Then, a shortest path algorithm is used to find the optimal path, with the least interference effects. Simulation results further validate the performance of our proposed scheme and show that it achieves better coverage rates and generates less interference when compared to other schemes, that do not account the cellular communication metrics. Indeed, our proposed solution guarantees a 100% connectivity rate, and generates a total interference of 22 dBm, as compared to the two other schemes that generate interference levels of 26 dBm and 27 dBm.