一种低信噪比下的高精度射频指纹变换方法

针对低信噪比时无线发射机的射频指纹识别问题，提出了一种基于功率放大器非线性系数的射频指纹变换方法。基于功放非线性与无线信道模型，以及通信帧的先验知识，利用卡尔曼滤波方法估计功放模型的非线性系数，并将系数矢量作为射频指纹，用于相应发射机的硬件识别。理论分析与数值仿真表明：新的射频指纹变换方法，在低信噪比时仍具有高精度的优点。提出的射频指纹变换方法可应用于无线或有线通信个体的物理层融合识别等。

High Accuracy Radio Frequency Fingerprint Transform Method in Low SNR Environment

Aiming at the radio frequency(RF) fingerprint identification of the wireless transmitter in low SNR condition, a novel RF fingerprint transform method based on nonlinear parameters in power amplifier for wireless transmitters is proposed. Based on nonlinear power amplifier models and wireless channel, Kalman filter is applied to estimate the nonlinear coefficients of the model of amplifier with the prior knowledge of communication frames,and the coefficient vectors are used as RF fingerprints for the identification of the according transmitters hardware. Theoretical analysis and numerical simulations demonstrate that the novel RF fingerprint transform method has the advantage in high accuracy at low signal to noise ratio(SNR). The proposed RF fingerprint transform method can be used in the physical layer fusion identification of wireless or wire communication individuals.