Outage probability optimization of UAV relay system based on elliptical trajectory

Unmanned aerial vehicles (UAVs), which enable both high flexibility and low cost, have been widely used in both military and civilian application scenarios. In this paper, we investigate a fixed-wing UAV relay system, where the fixed-wing UAV acts as a mobile relay with an elliptical trajectory between base station and ground users with broken communication links because of obstructions. Different time and power allocations are utilized to compute the outage probability among the Rician fading channel model. Due to the complexity of the formulated issue, we approximate the asymptotic solution using the first-order Maclaurin series convex optimization. Finally, we contrast the elliptical trajectory relay's outage probability performance with that of the circular trajectory relay and the fixed relay. In the meanwhile, we examine the impact of the elliptical trajectory's various long and short axis ratios on the outage probability of a relay system. The efficiency of the suggested elliptical trajectory relay method has been demonstrated in simulations.