Radio frequency fingerprint recognition method capable of defending multipath interference

Abstract

The invention belongs to the technical field of wireless communication, and specifically relates to a radio frequency fingerprint recognition method capable of defending multipath interference. According to the radio frequency fingerprint recognition method capable of defending multipath interference provided by the invention, aiming at the weak difference of the carrier frequency at radio frequency ends of radiation sources, two radio frequency fingerprint features of the radiation sources are respectively extracted from preambles by using an integral method and an envelope extraction method,and then the radiation sources are recognized and classified by using a K nearest neighbor classification method. Compared with the problem in the traditional radio frequency fingerprint recognitiontechnology that the impact of the multipath interference of wireless channels is not considered, leading to performance degradation of the traditional technology under multipath channel conditions, the radio frequency fingerprint recognition technology using the preamble as the research object has the advantages of extracting main path signals on a receiving end by using the autocorrelation of a pseudo random sequence and performing power normalization on dispreading signal by using the fast Fourier transform, thereby avoiding the pollution of random fading to radio frequency fingerprints of aradio while relieving the multipath interference.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a radio frequency fingerprint identification method capable of resisting multipath interference by using a communication system preamble. Background technique [0002] With the wide application of wireless communication, communication information security has become an important research topic. Existing secure communication technologies are more designed from the protocol layer. The network verifies the legitimacy of the client by verifying a pre-agreed unique identity number sent by the client. However, once the user’s identity information If leaked, criminals can use their own radio stations to imitate legitimate users to access the network and carry out criminal activities. [0003] In order to avoid this situation, considering that the communication stations used by criminals are different from those of legitimate users, and any two communication r...

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Problems solved by technology

[0005] The purpose of the present invention is to address the problem of performance degradation in multipath channels due to the fact that the prior art does not consider the influence of multipath interference in the field of radio frequency fingerprint identification. The signal is despread to extract the main path signal, combined with the integral (integral method) and cubic polynomial fitting (envelope method) in the feature extraction process to reduce the interference of the delay path, and then according to the power amplitude of the DC part after FFT transformation. Spread the signal for power normalization to reduce the impact of random fading on the signal, and the invention has the characteristics of small computational complexity and insensitivity to noise

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