Security performance analysis of RIS-assisted UAV wireless communication in industrial IoT

With the development of the unmanned aerial vehicle (UAV), UAV is widely used in various fields, such as Industrial IoT. Usually, the communication between UAV and the ground node is the line-of-sight (LoS) transmission. However, the performance of the UAV wireless communication system degrades greatly as the LoS links are prone to deteriorate in some complex communication scenarios. Fortunately, the quality of the communication link can be improved effectively by placing reconfigurable intelligent surfaces (RISs) into the ground nodes and UAV. Motivated by this, by optimizing the RIS passive beamforming, the ground user association, the UAV trajectory and transmit power synthetically, in this paper, we propose a secure RIS-assisted UAV wireless communication system based on multiple ground users to maximize the minimum average security rate among ground users. Also, we conduct an efficient algorithm based on the block coordinate descent (BCD) and successive convex approximation (SCA) methods to solution the no-convex optimization problem. Compared with the benchmark algorithm, the simulation results show that the proposed algorithm can improve the security performance of the RIS-assisted UAV wireless communication system effectively.