Path Planning and Optimization of a UAV-Based Relay Communication System with Co-channel Interference

Unmanned aerial vehicle (UAV) based relay communication is an important technical scheme for long-distance wireless communications. However, the UAV-based relay communication system is susceptible to co-channel interference. In this paper, to improve the link reliability of the UAV-based relay communication system, a path planning method was proposed for the UAV. First, a two-hop decode-and-forward (DF) relay communication system model was presented, in which the UAV acted as a relay platform between a mobile access point (AP) and a fixed base station (BS). Then an analytical expression of the outage probability of the system was derived. Based on the criterion of minimizing the outage probability, the problem of jointly optimizing the UAV’s heading and flight speed was formulated and addressed by the Nelder-Mead simplex algorithm. The simulation results demonstrated the validity of this proposed path planning method.