摘要
针对双向无线协作通信系统的安全传输(信息论安全)问题,提出一种基于多节点协作波束形成的中继与阻塞混合机制来提高物理层信息传输的安全性.其基本思想是:在协作传输阶段,系统中的一部分协作节点进行分布式波束形成来帮助发送方发送信息给合法用户,同时另一部分协作节点发送干扰信号阻塞窃听者的侦听,从而显著改善系统在协作广播阶段的安全性能.基于这一机制,针对窃听者的瞬时信道状态信息已知与否,本文提出两种不同的协作波束形成方法和优化方案,这两种方案在数学上均归结为解决一个或一系列的二阶凸锥规划问题,从而可以通过内点法有效地求解.仿真结果和对比实验验证了在中继节点数目较多时本文提出的混合安全机制和波束形成方法相对于单纯的协作中继机制或单纯的协作阻塞机制而言显著地提高了系统的物理层安全性能.
To improve the information-theoretic security of two-way wireless cooperative communication sys- tems, we propose in this study a hybrid relaying and jamming mechanism based on multi-node cooperative beamforming to enhance the security of the physical layer transmission of information. The basic concept is that in the cooperative transmission phase, some intermediate nodes adopt distributed beamforming to help the transmitter send messages to legitimate users and simultaneously others jam the eavesdropper, which can significantly improve the security performance of the system in the broadcast phase. Two different cooperative beamforming schemes are proposed with and without the instantaneous channel state information （CSI） of the eavesdropper. We show that optimizing both the schemes requires the mathematical solving of one or a series of second-order convex cone programming （SOCP） problems, which can be executed by efficiently using the interior point method. Simulation and comparisons show that our proposed hybrid relaying, jamming mechanism and beamforming approaches significantly increase the security sum rate of the two source terminals and outperform both the relays-only and jammers-only mechanisms when the number of intermediate nodes is relatively large.
出处
《中国科学：信息科学》
CSCD
2013年第4期445-458,共14页
Scientia Sinica(Informationis)
基金
国家自然科学基金(批准号:61071125
61102081
61172092
60921003)
教育部博士点基金(批准号:20110201120013)
陕西省自然科学基础研究计划(批准号:2011JQ8022)
中央高校基本科研业务费(批准号:2011jdhz06)资助项目
关键词
双向协作网络
无线通信
物理层安全
协作波束形成
人工噪声
安全速率
凸优化
two-way cooperative network, wireless communication, physical layer security, cooperative beam-forming, artificial noise, security rate, convex optimization
