Joint Optimization of Trajectory Planning and User Association for Secure VLC-UAV Communications with Friendly Jamming

Visible light communication (VLC) assisted unmanned aerial vehicles (UAVs) can offer a promising solution of high data rate transmission and mobile illumination in specific field of night monitoring safety and diaster rescue applications. However, it is highly susceptible to malicious interference and eavesdropping attacks due to the openness and broadcast characteristics of VLC. In this paper, a friendly jamming scheme is proposed to combat these problems and further improve the secrecy performance of VLC-UAV system, which is mathematically formulated as joint optimization of user association and trajectory planning as come up against the No-fly zone. We decompose the original problem into two sub-problems, and then transform them to be binary programming and convex optimization problems with the well-designed successive convex approximation method. Moreover, we proposed an efficient algorithm to obtain the optimal solution by using the block coordinate descent method in an alternating iterative way. Numerical results show that the proposed method can achieve the significant secrecy performance gain as compared with the conventional schemes.