基于智能反射面辅助的无人机中继系统安全通信方法

To improve the security of wireless transmission system and solve the problem that wireless channel is easily blocked by obstacles, a secure communication method based on an Intelligent Reflecting Surface (IRS) assisted Unmanned Air Vehicle (UAV) relay system is proposed. In the proposed method, the minimum-secrecy are maximized by jointly optimizing the position of UAV, beamforming at base station and phase shifts of IRS. To solve this complicated non-convex optimization problem, the original problem is divided into UAV position optimization sub-problem, beamforming and IRS’s phase shifts optimization sub-problem. The first order Taylor expansion method is applied to handle the non-convex terms of the optimization problems. Then, an alternate optimization algorithm is proposed to solve the problem. The simulation results shows that the proposed algorithm can improve the minimum-secrecy rate, and its convergence is well.