Location-Invariant Radio Frequency Fingerprint for Base Station Recognition

Pseudo base station (BS) is an illegal radio device that exploits the security vulnerabilities of fifth generation (5G) communications and then implements corresponding network attacks, such as spoofing attack. These malicious actions cause security and privacy threats and hinder the wide deployment of wireless access networks. To address these problems, efficient BS identification mechanisms are necessary. Radio frequency fingerprinting (RFF) and channel fingerprinting are potential solutions. Unfortunately, existing solutions are limited to be applicable to scenarios where the locations of pseudo BSs are fixed, while the emerging challenges brought by movable pseudo BSs can hardly be addressed by mature wireless security mechanisms. In this letter, we propose a signal echoing protocol (SEP) to reduce the influence on wireless channels and construct the location-invariant RFF. When BS and user equipment (UE) communicate using SEP, UE can accurately estimate the channel to recognize different BSs. Numerical results demonstrate that the proposed scheme can reach a high classification accuracy for ten BSs, by 95.2% at the signal-noise ratio (SNR) of 25 dB.