物理层认证技术是近年来兴起的新型身份认证方式，它将身份认证信息包含在 物理层的无线通信信号中，从而在物理层实现身份认证． 该技术一方面能够实现身份认证 对上层协议的透明化，降低上层协议的开销;另一方面能避开针对上层协议的身份认证攻 击，提高系统的安全性． 文中介绍了物理层认证的两项关键技术———射频指纹和射频水 印，为现有文献中提出的技术方案建立了一个统一的分类体系，讨论了现有方案的优缺 点，最后探讨了该领域未来的发展方向． 

 Physicallayer authentication technology is a new type of identity authentication in recent years． It embeds identity authentication information in the wireless communication signal of physical layer， so as to realize identity authentication in physical layer． On the one hand， this technology can achieve authentication，with transparency of upper layer protocol，and lower overhead of upper layer protocol; on the other hand， it can avoid identity authentication attacks for highlevel protocols and improve system security． This paper introduces two key technologies of physical layer authentication: radiofrequency fingerprint and radiofrequency watermarking． Then，a unified classification system for the proposed methods in the present literature is established， the advantages and disadvantages of the existing schemes are investigated，and，finally，the future development direction in this field is discussed．