We discuss the use of angle of arrival (AoA) as an authentication measure in analog array multiple-input multiple-output (MIMO) systems. A base station equipped with an analog array authenticates users based on the AoA estimated from certified pilot transmissions, while active attackers manipulate their transmitted signals to mount impersonation attacks. We study several attacks of increasing intensity (captured through the availability of side information at the attackers) and assess the performance of AoA-based authentication using one-class classifiers. Our results show that some attack techniques with knowledge of the combiners at the verifier are effective in falsifying the AoA and compromising the security of the considered type of physical layer authentication.

翻译：本文探讨了在模拟阵列多输入多输出系统中使用到达角作为认证手段的方法。配备模拟阵列的基站通过经认证的导频传输所估计的到达角对用户进行身份验证，而主动攻击者则通过操纵其发射信号发起冒充攻击。我们研究了强度递增的多种攻击方式（通过攻击者侧信息可用性进行刻画），并利用单类分类器评估了基于到达角的认证性能。结果表明，当攻击者掌握验证端合并器信息时，某些攻击技术能够有效伪造到达角，从而危及所研究的物理层认证方案的安全性。