Optimal Placement of UAV-Assisted Free-Space Optical Communication Systems With DF Relaying

In this letter, by characterizing source-to-relay and relay-to-destination channel models of the considered unmanned aerial vehicle (UAV)-assisted free-space optical (FSO) relay link, we derive the optimal 3D coordinates of UAV relay as well as optimal optical beam pattern in order to minimize the outage probability. Moreover, we study the impact of physical parameters (such as strength of orientation fluctuations of UAV, height and position of obstacles) on the optimal location of UAV relay.