基于非理想CSI的全双工双向中继系统保密中断概率性能研究

Research on security outage probability performance in full-duplex two-way relay system with imperfect CSI

研究基于译码转发的全双工中继系统的物理层安全问题。假设系统模型中窃听者与合法用户以及中继之间存在直接链路,考虑在合法用户和中继之间的信道状态信息(channel state information,CSI)是非理想的情况下,通过分析信道估计误差、窃听信道的平均信噪比和残余自干扰对中继系统物理层安全的影响,推导出每个节点端到端瞬时信干噪比和非理想CSI下的保密中断概率表达式。仿真结果表明,信道估计误差、窃听信道的平均信噪比和残余自干扰越小,系统保密中断概率越小,系统安全性能越高;在高信噪比时,残余自干扰对保密中断概率的影响可以忽略不计;同时,全双工中继方案优于传统的半双工中继方案。

The paper studied the physical layer security problem of full-duplex relay system based on decode-and-forward.There was the direct link between the eavesdropper and legitimate users or relay in the system model,and the channel state information( CSI) between legitimate users and the relay was imperfect. By analyzing the influence of channel estimation error,average signal-to-noise ratio of eavesdropping channel and residual self-interference on the physical layer security of the relay system,it derived the expressions of end-to-end instantaneous signal-to-noise ratio of each node and secrecy outage probability under imperfect CSI. The simulation results show when the channel estimation error,the average signal-to-noise ratio of the eavesdropping channel and residual self-interference are smaller,the system security outage probability is smaller,and the system security performance is better. At high signal-to-noise ratio,the effect of residual self-interference on the security outage probability is negligible. At the same time,the full-duplex relay scheme is superior to the traditional half-duplex relay scheme.