| The rapid development of wireless communication technology has brought great convenience to the production and life of human society.However,due to the openness and broadcasting of wireless network,wireless communication is vulnerable to malicious attacks such as forgery,tampering,eavesdropping and interference by illegal users.Therefore,the security of wireless network communication needs to be paid attention to.The traditional wireless communication security technology is based on cryptography on the physical layer,and improves the security performance by increasing the computational complexity.In recent years,authentication and encryption technology based on wireless physical layer security can be used to further improve the security of wireless network.In this thesis,the radio frequency identification and physical layer key generation of wireless anti-interference communication security technology is studied and analyzed in depth,the main content and innovation are as follows:Firstly,a method of identification of wireless devices based on machine learning is proposed by using the radio frequency identification information of wireless communication equipment in complex electromagnetic environment.The transmitter sends RF signal,the receiver collects the signal and extracts the characteristics of the RF fingerprint.The machine learning algorithm is used to train and learn the feature image information of the RF fingerprint.In the test stage,the classifier and entropy value are calculated and compared with the preset threshold to identify and distinguish the legitimate device users and the illegal device users.After a large number of sample tests,the results show that the recognition accuracy of the method for legal equipment and illegal equipment is above 98% and 90% respectively,and can effectively distinguish different legal devices,which ensures the security of identification and authentication of wireless communication system.Secondly,on the basis of device authentication,a key generation method of physical layer based on wireless channel is proposed.Using the fast time-varying and reciprocity of the channel,the two sides of the communication send pilot sequences to each other for channel estimation,extract the instantaneous state information of the channel,quantize and encode each to generate a series of initial keys,and then ensure the consistency of the keys of the two sides through information negotiation.After that,both sides can use the consistent key to encrypt communication.Compared with the traditional encryption method,the physical layer key can achieve "one key at a time" without distribution management,which avoids the key leakage problem.Through the simulation analysis of the demonstration system,the average bit change rate of each new key and the last key is 41.9%,which ensures the randomness of the key generation.This method effectively improves the security performance of the wireless communication system.Finally,a frequency hopping sequence design method based on physical layer key is proposed,which uses the key as the initial seed to generate frequency hopping pattern to realize frequency hopping anti-interference communication.In order to demonstrate the research content more intuitively,this paper uses software radio peripheral USRP and software radio development platform Lab VIEW to realize the functions of authentication,encryption and frequency hopping,including RF fingerprint collection and extraction,key generation and negotiation,frequency hopping communication and other modules.In view of the specification limitation of usrp-2920 equipment,the demonstration platform of anti-interference frequency hopping communication system is built to achieve the average frequency hopping rate every two seconds.In this thesis,the feasibility and effectiveness of the proposed scheme are evaluated through the demonstration results and data simulation analysis of the above development platform. |
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