窃听者随机分布下智能反射面辅助的MISO系统物理层安全性能分析

Performance Analysis of Physical Layer Security for IRS-aided MISO System with Randomly Distributed Eavesdropping Nodes

针对窃听节点随机分布的MISO系统通信场景,该文分析了智能反射面(IRS)辅助下的安全通信性能。采用随机几何理论,将窃听节点建模为均匀泊松点过程(PPP)。合法发送节点采用天线选择策略,选择最优链路发射信号,并部署智能反射面实时调控反射相移增强链路质量,然后以传输安全中断概率为性能指标,推导了其闭式表达式,分析了反射单元数量、发射天线数量等参数对中断概率的影响,最后给出了最大化安全性能的参数选择策略。仿真结果验证了理论分析的正确性,并表明部署反射面可以在低能耗下提升安全性能。

The security performance of Multiple-Input Single-Output(MISO)system with the aid of the Intelligent Reflecting Surface(IRS)is analyzed in this paper,where eavesdropping nodes are randomly distributed.The stochastic geometry theory is utilized to model the eavesdropping nodes as a homogeneous Poisson Point Process(PPP).With the transmit antenna selection strategy,the legitimate node selects the optimal link to transmit signal.And the phase shifts at the IRS are tuned to enhance the selected link quality.Then,considering the transmission secrecy outage probability as the performance metric,the closed expression of scheme is derived.Further,the impact of the parameters,such as the number of reflection units and transmitting antennas,on the outage probability is analyzed.Finally,the design strategy of parameters for maximizing the security performance is given.The simulation results verify the theoretical analysis and show that the proposed scheme can improve the security performance under low energy consumption.