存在辅助节点的MIMO窃听信道安全性能研究

Research on Secrecy Performance of MIMO wiretap channel with a Helper

为了提高MIMO窃听信道的可达安全速率,提出了基于广义奇异值分解的合作干扰策略。该策略中源节点和辅助节点同时采用基于广义奇异值分解的波束形成技术,源节点发送消息信号,辅助节点发送独立于消息信号的噪声信号,噪声信号对目的节点和窃听节点都产生干扰。此外设计了源节点和辅助节点采用合作干扰策略时的联合最优功率分配算法。该算法可以实现源节点和辅助节点在总功率受限时的可达安全速率最大化。仿真结果表明,与现有的非合作最优功率分配算法相比,本文提出的合作干扰策略在大信噪比时可以显著提高系统的可达安全速率。

To improve the achievable secrecy rate in MIMO wiretap channel, a cooperative jamming strategy based on generalized singular value decomposition （GSVD） is proposed. Beamforming based on GSVD is employed both at the source node and helper node. The source node sends messages, while the helper transmits jamming signals independent of the source messages. The jamming signal is treated as noise at both the intended node and the eavesdropper node. Further- more, joint optimal power allocation algorithm is designed between the source and the helper to maximize the achievable se-crecy rate, under total power constraints. Compared with the existing optimal non-cooperative scheme, the numerical results demonstrated that the proposed strategy achieves a higher achievable secrecy rate in the high SNR.