基于GNU Radio和USRP的切换天线方向调制物理层安全系统

提出了一种切换天线方向调制物理层安全传输系统，利用天线的切换选择扰乱非期望方向的窃听者进行信息窃密，实现了视距空间的保密通信。基于GNU Radio和USRP软件无线电平台，结合高速射频开关、FPGA控制板、网络收发模块以及阵列天线搭建了实验验证系统。通过测试窃听者位于不同方位角的视频传输质量和信号星座样式验证了该方法的可行性，结果表明与传统阵列天线相比，切换天线方向调制技术能提供更安全的视距通信。

A Switched Antenna Directional Modulation Physical Layer Security System Based on GNU Radio and USRP

In this paper, a directional modulation physical layer security system is proposed, which distorts the signal format of eavesdroppers from undesired directions by switching ratio frequency switch. Then an experimental system is established by the use of high speed switch, FPGA control board, network group and array antenna. The structure is mainly based on GNU Radio and USRP software radio platform. Feasibility of the proposed system is validated by testing the performance of video transmission and constellations patterns along different directions. Experimental results show that, compared with traditional array antenna systems, this method can improve the security of line of sight communication.