双向多天线中继系统中的安全波束成形  

Secure beamforming for two-way multiantenna relay systems

作　　者：黄宇 张立健[1] 金梁[1] 刘璐[1] 楼洋明[1] 

机构地区：[1]国家数字交换系统工程技术研究中心,郑州450002

出　　处：《中国科学：信息科学》2018年第2期221-232,共12页Scientia Sinica(Informationis)

基　　金：国家高技术研究发展计划(863)(批准号:2015AA01A708);国家自然科学基金(批准号:61601514;61379006;61501516);中国博士后科学基金(批准号:2016M592990)资助项目

摘　　要：针对双向多天线中继系统中信息易被窃听的问题,提出了两种安全波束成形方案:安全和速率最大化波束成形(secrecy sum rate maximization beamforming,SSRMB)与零空间波束成形(null space beamforming,NSB).SSRMB方案中,采用具有收敛特性的连续凸估计策略,对非凸的安全和速率最大化问题进行求解,得到局部最优波束成形解.针对中继节点的天线个数大于窃听节点个数这一特殊场景,设计了低复杂度NSB方案,将中继转发的信息投影到等效窃听信道矩阵的零空间中,通过求解一个广义Rayleigh熵问题获得波束成形解.仿真结果表明,所提方案可以有效地提高系统的安全性能,SSRMB方案具有快速收敛特性.In two-way nmltiantenna relay systems, confidential information can be easily intercepted by eaves- droppers. To overcome this problem, two secure beamforming schemes are proposed： secrecy sum rate maximiza- tion beamforming （SSRMB） and null space beamforming （NSB）. For the SSRMB scheme, the nonconvex secrecy sum rate maximization problem is solved using a successive convex approximation strategy, which is convergent. The obtained beamforming solution is locally optimal to the original problem. For the special scenario where the number of antennas at the relay is more than the number of eavesdroppers, the NSB scheme with a low com- plexity is proposed. The beamforming solution is obtained by solving a generalized Rayleigh quotient problem. Simulation results demonstrate that the proposed schemes can effectively improve the security performance, and the SSRMB scheme has a fast convergence rate.

关 键 词：物理层安全 安全和速率 连续凸估计 零空间波束成形 半定规划 

分 类 号：TN92[电子电信—通信与信息系统]