Secure data rate maximization for full-duplex UAV-enabled base station

Unmanned Aerial Vehicle (UAV) is an air base station featuring flexible deployment and mobility. It can significantly improve the communication quality of the system due to its line-of-sight channel connection with ground devices. However, due to the openness of UAV-to-Ground channels, the communication between ground users’ devices and UAV is easily eavesdropped. In this paper, we aim to improve the security of communication system by using full-duplex UAV as a mobile air base station. The UAV sends interference signals to eavesdroppers and receives signals from ground devices. We jointly optimize the scheduling between the UAV and ground devices, the transmission power of the UAV and ground devices, as well as the trajectory of the UAV to maximize the minimum average security communication data rate. This optimization problem is mixed with integers and non-convex expressions. Therefore, this problem is not a standard convex optimization problem, which can not be solved with standard methods. With this in mind, we propose an effective algorithm which solves this problem iteratively by applying Successive Convex Approximation (SCA), variable relaxation and substitution. Finally, numerical results demonstrate the effectiveness of the proposed algorithm.