基于嵌入水印的物理层认证及优化

Physical Layer Authentication and Optimization based on Embedded Watermark

物理层认证具有兼容性好、节约频谱资源的优点,为验证发射机身份提供了一种新的途径。现有的嵌入水印式物理层认证研究只考虑虚警率约束,导致低信噪比时存在认证标签漏检率过高的问题。针对这一问题,联合考虑鲁棒性和安全性,提出了改进的认证方案。改进方案通过优化判决阈值,最小化接收端对认证标签的错检概率,提升接收端低信噪比时认证标签的检测能力。仿真结果表明,与已有文献相比,采用最佳判决阈值可以有效提高合法端成功认证概率。尽管窃听端也可以采用类似方法提升检测准确率,但综合来看,合法端性能提升更显著。

Physical layer authentication,with the advantages of good compatibility and saving spectrum resource,provides a new way to verify the identity of transmitter.The existing watermark embedded physical layer authentication research only considers the constraint of false alarm rate,which leads to the problem of high missed detection rate of authentication tags when the SNR is low.In response to this problem,considering the robustness and safety jointly,an improved authentication scheme is proposed.The improved scheme minimizes the error detection probability of the authentication tag at the receiving end by optimizing the decision threshold,and improves the detection ability of the authentication tag at the receiving end when the SNR is low.The simulation results show that,compared with the existing literature,adopting the optimal decision threshold can effectively increase the probability of successful authentication of the legal end.Although the eavesdropper can also use similar methods to improve the detection accuracy,the overall performance improvement of the legal end is more significant.