Three-Dimensional Trajectory Optimization for Secure UAV-Enabled Cognitive Communications

• 作 者: Yuhan Jiang Jia Zhu
• 机 构: School of Telecommunications and Information Engineering,Nanjing University of Posts and Telecommuni
• 出 处: 中国通信（英文版）
• 发表日期: 2021年12期
• 关键词: UAV-enabled cognitive communications physical-layer security trajectory optimiza

Unmanned aerial vehicles (UAVs) are en-visioned as a promising means of providing wireless services for various complex terrains and emergency situations.In this paper,we consider a wireless UAV-enabled cognitive communication network,where a rotary-wing UAV transmits confidential information to a ground cognitive user over the spectrum assigned to primary users (PUs),while eavesdroppers attempt to wiretap the legitimate transmission.In order to en-hance the secrecy performance of wireless communi-cations,the secrecy rate (SR) of the UAV-enabled cog-nitive communication system is maximized through optimizing UAV three-dimensional (3D) flying trajec-tory while satisfying the requirements of UAV\'s initial and final locations and guaranteeing the constraint of maximum speed of UAV and the interference thresh-old of each PU.However,the formulated SR maxi-mization (SRM) problem is non-convex.For the pur-pose of dealing with this intractable problem,we em-ploy the difference of two-convex functions approxi-mation approach to convert the non-convex optimiza-tion problem into a convex one,which is then solved through applying standard convex optimization tech-niques.Moreover,an iterative 3D trajectory opti-mization algorithm for SRM scheme is proposed to achieve the near-optimal 3D trajectory.Simulation re-sults show that our proposed 3D trajectory optimiza-tion based SRM algorithm has good convergence,and the proposed SRM scheme outperforms the bench-mark approach in terms of the SR performance.