人工噪声辅助的多用户安全传输方法

针对传统人工噪声辅助的安全传输方法无法适用于发射天线数等于接收天线数的多用户(Multiuser, MU)多输入多输出(Multiple-Input Multiple-Output, MIMO)系统的问题，提出了一种人工噪声辅助的多用户安全传输新方法。通过合理设计人工噪声与预编码矩阵，该方法可在同时满足所有用户传输需求的基础上，显著提升发射天线数等于接收天线数的MU-MIMO系统的安全性。同时，针对提出的方法进行了检测算法与平均保密速率的推导与分析。理论分析与仿真结果表明，所提方法可有效提升无线通信系统的安全性，在信噪比为20 dB时，该方法较传统方法的平均保密速率提升达到120%。

An artificial noise-aided secure multiuser transmission approach

In multiuser multiple-input multiple-output(MU-MIMO) systems,conventional artificial noise(AN)-aided secure transmission approaches cannot guarantee the transmission security when the number of transmitting antennas is the same as that of legitimate receiving antennas.To mitigate this problem,a new AN-aided secure MU transmission approach is proposed to enhance the physical layer security.Specifically,through a careful design of AN and the precoding matrix,the proposed approach is capable of satisfying the transmission requirements of all users while enhancing the information security in MU-MIMO systems,when the number of transmitting antennas is the same as that of legitimate receiving antennas.Furthermore,the detection algorithms and the average secrecy rate of the proposed approach are investigated.Both analytical and simulation results demonstrate that,the proposed approach significantly enhances the physical layer security of wireless communications.Compared with the conventional approach,the proposed approach can realize up to 120% higher secrecy rate at 20 dB signal-to-noise ratio.