Physical Layer Authentication for Mobile Systems with Time-Varying Carrier Frequency Offsets

• Published in: IEEE transactions on communications Vol. 62; no. 5; pp. 1658 - 1667
• Main Authors: Weikun Hou, Xianbin Wang, Chouinard, Jean-Yves, Refaey, Ahmed
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.05.2014; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Applied sciences; Authentication; Carrier frequencies; carrier frequency offset (CFO); Channels; Cryptography; Detection, estimation, filtering, equalization, prediction; Devices; Doppler shift; Estimation; Exact sciences and technology; Fading; Hypothesis testing; Information, signal and communications theory; Kalman filtering; Kalman filters; Mathematical models; Offsets; Physical layer; Physical layer authentication; Radiocommunication specific techniques; Radiocommunications; Signal and communications theory; Signal to noise ratio; Signal, noise; Signatures; Telecommunications; Telecommunications and information theory; Transmitters. Receivers; Wireless communication; Wireless communications; Target tracking; Prototype; hypothesis testing; Wireless telecommunication; Transmitter; Doppler effect; Stochastic process; Radiofrequency; Discrimination task; Time variation; Hypothesis test; Carrier frequency; Simulation; Oscillator; carrier frequency offset (CFO); Authentication; Radiometry; Physical layer authentication; Feasibility; Kalman filtering; Frequency offset; Autoregressive processes; Software radio; Signal to noise ratio
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2014.032914.120921

A novel physical layer authentication scheme is proposed in this paper by exploiting the time-varying carrier frequency offset (CFO) associated with each pair of wireless communications devices. In realistic scenarios, radio frequency oscillators in each transmitter-and-receiver pair always present device-dependent biases to the nominal oscillating frequency. The combination of these biases and mobility-induced Doppler shift, characterized as a time-varying CFO, can be used as a radiometric signature for wireless device authentication. In the proposed authentication scheme, the variable CFO values at different communication times are first estimated. Kalman filtering is then employed to predict the current value by tracking the past CFO variation, which is modeled as an autoregressive random process. To achieve the proposed authentication, the current CFO estimate is compared with the Kalman predicted CFO using hypothesis testing to determine whether the signal has followed a consistent CFO pattern. An adaptive CFO variation threshold is derived for device discrimination according to the signal-to-noise ratio and the Kalman prediction error. In addition, a software-defined radio (SDR) based prototype platform has been developed to validate the feasibility of using CFO for authentication. Simulation results further confirm the effectiveness of the proposed scheme in multipath fading channels.