Gauss信道估计误差下DF与RF中继SIMO系统保密通信性能分析

Analysis of secure communications for a DF and RF relaying SIMO system with Gauss errors

本文研究了经典的四点(信源、中继、信宿、窃密者)协作模型的物理层保密性能.在此协作模型中,信源通过中继向信宿发送信息,中继分别采用解码放大转发(decode-and-forward,DF)和随机放大转发(randomize-and-forward,RF)两种中继方式向信宿转发信息.同时,信源与中继、中继与信宿两跳通信中均遭到窃密者的窃听.考虑信源和中继均为单天线,信宿和窃密者为多天线的单输入多输出窃密信道模型.信宿和窃密者采用最大比合并策略处理多径信号.在考虑Gauss信道估计误差下,首先推导出DF协议下信噪比的概率密度分布和累积概率密度分布的闭式表达式,然后分别推导出DF与RF中继协作的非零保密容量概率的闭式表达式.最后,通过Monte Carlo仿真验证了理论模型的正确性.

This paper investigates a cooperative system for the typical four-node（source,relay,destination,and eavesdropper） scenario in physical-layer security.In the cooperative system,the source transmits its message to the destination via the relay,which adopts decode-and-forward（DF） and randomize-and-forward（RF）schemes to forward the information from the source to the destination,respectively.However,the eavesdropper wants to overhear the information of the source-relay link and the relay-destination link over the two hops.We consider single-input,multiple-output（SIMO） wiretap channels,where the source and the relay are equipped with a single antenna and the destination and eavesdropper are equipped with M and N antennas,and adopt a maximal ratio combining to deal with multipath signals.Considering Gauss channel estimation errors,we first derive the closed-form expressions for the probability density function and cumulative distribution function of the received signal-to-noise ratio at the destination and the eavesdropper,respectively,under the DF scheme;then,the closed-form expressions for the probability of non-zero secrecy capacity are derived under the DF and RF schemes,respectively.Finally,the accuracy of our proposed expressions is verified by simulation results.