Wireless device authentication through transmitter imperfections — measurement and classification

This paper is oriented in the area of wireless device identification through the analysis of emitted signals corrupted by radio frequency transmitter impairments. These impairments (such as power amplifier nonlinearity, IQ modulator imbalance, DC offset, phase noise, carrier frequency offset, shaping filter length and its shape) represent a unique characterization of any radio wireless transmitting device. We have performed a set of measurements on a sample of nine different transmitters (three baseboards plus three different front-ends) based on USRP software defined radio family in order to verify the potential of real applications of this authentication principle. After performing measurements in ideal conditions, we further proceeded in simulating a simple classifier based on gaussian mixture models and we briefly evaluated its performance in a real situation of a radio transmitting through air to the vector signal analyzer serving as the receiver. We also analyzed the influence of number of measurements on the classifier performance.