自适应窃听和干扰下机会式中继和协作干扰技术的安全性能分析

Secure performance analysis of opportunistic relay and cooperative jamming technique under adaptive eavesdropping and jamming

在存在一个半双工自适应窃听者的多中继协作通信模型中,针对窃听者能够智能地选择被动窃听或主动干扰的问题,选择一个中继协助源节点转发信息,其余中继用于发送人工干扰信号以混淆窃听者,从而提升系统的遍历可达安全速率(Ergodic achievable secrecy rate,EASR)性能。在仅有窃听信道统计信息的假设下,推导了EASR的渐进闭合表达式,并进行了Monte-Carlo仿真验证。仿真结果表明:即使在中继数目较小的情况下,渐进分析结果与仿真结果也基本吻合。同时表明:采用机会式中继和中继协作干扰的组合技术可显著地提升系统的安全传输性能。

A multi-relay cooperative communication model is considered,where there exists a half-duplex adaptive eavesdropper that performs either passive eavesdropping or active jamming. To improve the performance in ergodic achievable secrecy rate(EASR),one cooperative relay is selected to assist the source node to transmit information,and the remaining relays are used to send artificial jamming to confuse the eavesdropper. Under the assumption that only the statistical channel state information of the eavesdropper is known,the asymptotic closed-form expression for the EASR is derived,and Monte-Carlo simulations are conducted to validate the derivations. Simulation results show that the asymptotic analysis results coincide well with the simulation results even when the number of relays are relatively small,and meanwhile,the combined opportunistic relaying and cooperative jamming technique can significantly improve the secure transmission performance of the system.