中文摘要：

针对现有方法中第二跳中继转发信息容易被窃听的问题, 提出一种基于协作波束成型的中继分组协作物理层安全方案。首先, 利用发送—中继—接收的级联信道将中继分为协同干扰组和协同中继组。然后, 两组中继分别利用噪声转发和译码转发策略, 相互协作提高保密速率; 最后, 在总功率受限下, 进行功率优化分配。仿真结果表明, 该方法比参考的中继分组方法获得的保密速率高, 并且随着转发功率的增加而提升; 相同功率下该方法能获得0. 6 bps/Hz的性能提升。因此该方案能够有效提升协作中继系统的安全性。

英文摘要：

Forwarded information in the second hop was vulnerable to be eavesdropped in traditional methods, this paper proposed a group cooperation method for physical layer security based on cooperated beamforming. Firstly, it classified relays in two groups, cooperative jamming group and cooperative relaying group, based on the cascaded channel of sending-relaying-receiving. Secondly, it cooperated the two groups by decode-and-forward strategy and noise-and-forward strategy to improve the maximum secrecy rate. It classified the relays into collaboration jamming group and collaboration relaying group. Finally, it optimized power allocation to achieve maximize secrecy rate under the limited power. Simulation results show that the maximum secrecy rate in the proposed method is more high than the referenced method, and keep upgrading with the increasing of the power. Compared with the referenced method, the method proposed can promote 0. 6 bps/Hz performance. Therefore, this scheme can effectively improve the security of cooperative relay system.