Research On UAV Communication Network Security Transmission Technology Based On Trajectory Optimization

With the development of wireless communication,diversified communication scenarios have put forward higher requirements for wireless network throughput,ultralow energy consumption and reliability.Communication operators provide an efficient solution for building massive data connections with unmanned aerial vehicle(UAV)communication networks quickly in complex communication scenarios.Comparing to the traditional static wireless communication system,the UAV can communicate with the ground communication node by establishing a line-of-sight link(Lo S),which can provide better communication quality and reduce more resources.However,due to the openness of the channel and the dynamic topology of the UAV communication network,UAV communication is more vulnerable to eavesdropping attacks from hostile devices than traditional static wireless communications.Because of the movement of the UAV,when it communicates with other nodes,the channel characteristics will change with the movement of the UAV.The physical layer security is a communication security technology based on channel characteristics,so the trajectory of the UAV will have a decisive impact on the safe transmission performance of the system.It has a decisive influence on the safe transmission performance of the system.Therefore,how to effectively use the mobile characteristics of UAVs to improve the physical layer security method of wireless link security has become the research focus of UAV communication.This thesis mainly uses convex optimization theory to study the flight trajectory and resource allocation of UAV combined with the physical layer security mechanism to improve the communication security performance when the eavesdropper’s location information is known.This thesis mainly studies two issues: 1.In the wireless communication scenario where the UAV is used as a legal monitor,the UAV uses a joint flight trajectory and transmission power optimization method to maximize the legal monitoring rate.2.The security performance in the ground-to-ground communication scenarios of UAVs with multiple passive eavesdroppers on the ground is studied.Use a UAV as a cooperative interference UAV to send interference noise,interfere with the eavesdropping of eavesdroppers,and optimize the three-dimensional trajectory of the UAV.By modeling the optimization problem,the constructed original problem is a hybrid non-convex optimization problem with coupling optimization variables.By introducing slack variables to replace the complex expressions encountered in the optimization process,and using the successive covex approximation(SCA)algorithm to transform the original non-convex problem into an approximate sub-optimization problem,and then use the convex optimization method to solve the problem.The alternate iterative optimization algorithm is used for step-by-step optimization,and the effectiveness of the iterative optimization trajectory and power algorithm is verified through simulation,and the safety performance of the system can be significantly improved.