SWIPT不可信中继系统安全性能的优化

Optimization of Security Performance for SWIPT Untrusted Relay Systems

针对时间切换模式的无线携能传输(SWIPT)全双工中继系统,在中继为潜在窃听者的情况下,为提高物理层安全传输性能,提出一个由接收机进行协作干扰的方案,以及对能量传输和信息传输阶段的时间切换、源和目的节点的能量分配进行联合优化的算法。首先,中继节点为全双工SWIPT节点,在能量传输阶段接收射频信号中收集的能量,用于信息传输阶段信号的转发;其次,为防止不可信中继节点获得保密信息,全双工的目的节点在接收信号的同时进行协作干扰;最后,以最大化可达保密传输速率为目标,对时间切换因子、源和目的节点两个传输阶段的能量分配因子进行联合优化。仿真表明,对3个因子进行联合优化后,系统的可达保密速率要明显高于只优化其中2个、1个因子,或不进行优化的系统。

For a full-duplex time-switching simultaneous wireless information and power transfer(SWIPT)relay system,a scheme for collaborative jamming by the receiver is proposed to improve the performance of physical layer security in the case that the relay is a potential eavesdropper.Besides,an algorithm for joint optimization of the time switching and energy allocation of the source and destination node in the energy transmission and information transmission stages is also given.Firstly,the relay node is a full-duplex SWIPT node,which harvests energy from the signals received in the energy transmission stage for signal forwarding in the information transmission stage.Secondly,to prevent the untrusted relay from obtaining confidential information,the full-duplex destination node sends jamming signals while receiving signals.Finally,to maximize the achievable secrecy rate,the time switching factor and the energy allocation factors for both transmission stages at the source node and the destination node are jointly optimized.Simulation results show that the achievable secrecy rate of the optimized system is significantly higher than that of the system that optimizes only two or one of the factors,or no optimization.