智能反射面和协作干扰的无人机安全通信算法

为了进一步增强无人机通信系统的保密率，提出了基于智能反射面和协作干扰的无人机安全通信系统。通过利用智能反射面动态地加强回传链路以及通过协作无人机引入人工噪声干扰非法窃听者，从物理层提高无人机通信系统的安全性。考虑源无人机轨迹、干扰无人机轨迹、功率控制和智能反射面相移，以最大化系统的保密率为目标提出联合优化问题。提出了一种交替优化算法，将原问题变为4个子问题，并通过连续凸逼近、半定松弛将原始的非凸问题转换为近似凸性子问题，使其可通过凸优化工具直接求解。仿真结果表明，所提优化算法能够快速收敛，相比于传统的非智能反射面辅助的通信网络，所提算法能显著地提高系统的安全保密率。

UAV security communication algorithm with Intelligent Reflecting Surface and cooperative Jamming

In order to further enhance the secrecy rate of the unmanned aerial vehicle ( UAV )communication system, a UAV security communication system base on intelligent reflecting surface(IRS)and cooperative jamming is proposed. By using an IRS to dynamically strengthen the backhaul link andintroducing artificial noise through a cooperative UAV to interfere with a illegal eavesdropper, the securityof UAV communication system can be improved from the aspect of physical layer security. Consideringthe trajectory of the source UAV, the trajectory of the jamming UAV, the power control and the phaseshift of IRS, a joint optimization problem is proposed with the goal of maximizing the security of thesystem. An alternate optimization algorithm is proposed, which turns the original problem into four sub-problems, and converts the original non-convex problem into approximately convex sub-problems throughsuccessive convex approximation and semidefinite relaxation technique, so that it can be solved directlyby convex optimization tools. The simulation results show that the proposed optimization algorithm canconverge quickly. Compared with the traditional non-intelligent reflector-assisted communication network,the proposed algorithm can significantly improve the security rate of the system.