双智能反射平面辅助无线携能通信系统的安全通信优化

研究采用两个智能反射平面保障无线携能通信系统信息传输的物理层安全。通过联合优化两个智能反射平面的反射波束成形和基站的发射波束成形以最大化系统的总信息传输速率,同时满足基站的发射功率约束、能量收集用户的最小能量收集约束与最大窃听速率约束,以及智能反射平面反射系数的模一约束。由于存在两个智能反射平面之间的反射链路,所构建优化问题的优化变量高度耦合,难以直接求解。提出一种基于交替优化、半正定松弛和连续凸逼近的算法求问题的次优解。仿真结果表明,与现有的基准方案相比,所提算法能在保证信息传输安全和满足能量传输要求的情况下大幅提高系统的总数据速率。

Secure communication optimization for double-IRS assisted SWIPT system

Two intelligent reflecting surfaces(IRS)was applied to ensure the physical layer security of the information transmission in a simultaneous wireless information and power transfer(SWIPT)system,where a multi-antenna base station(BS)simultaneously transmits information and energy to multiple single-antenna information receivers(IR)and energy receivers(ER)and the ERs are regarded as potential information eavesdroppers.The system deploys two IRSs to ensure the security of information transmission while meeting the requirements of energy transmission.Due to the inter-IRS signal reflection,the variables of the considered optimization problem are highly coupled,thus the problem is difficult to solve.To tackle this difficulty,an algorithm based on the alternating optimization,semide-finite relaxation,and successive convex approximation methods was proposed to obtain a suboptimal solution to the problem.Simulation results show that the proposed algorithm can significantly increase the total rate of the IRs and guarantee the security of the information transmission and the requirement of energy transmission,as compared to some existing benchmark schemes.