Research On The Authentication Technology Of Wireless Physical Layer

In the information age where internet technology such as cloud technology and big data is changing rapidly,wireless communication is rapidly evolving into an all-round development stage and is about to enter the era of 5G.With the safe,reliable and efficient real-time communication needs,wireless communication technology is also put forward higher challenge.Because of its natural open nature,the wireless channels make communication transparent and make it more vulnerable to attack and interference such as information eavesdropping,tampering and counterfeiting.Among them,the imitation attack based on user identity is the common attack mode in wireless communication,so whether the user identity can be accurately authenticated is the basic guarantee of secure communication.Reliable physical layer transmission medium is the most basic guarantee for secure communication.It is a research hotspot in the field of wireless communication to realize secure communication by using the physical characteristics of the physical layer.Its essence is to encrypt and authenticate sending information by using the space-time specificity of transceiver channel and transmitting signal,to improve the reliability of information transmission,so that the amount of information obtained by eavesdropping is approaching zero.The physical layer security authentication technology can effectively prevent eavesdropping attacks,forming the first protection barrier in communication,and strengthen the security performance of the upper layer communication without any burden and extra overhead.This paper focuses on the physical layer authentication technology based on wireless channel characteristics,from wireless channel model,multi-path fading feature,physical layer authentication,performance analysis and so on.At the same time,the data processing algorithm in machine learning is introduced into the wireless communication OFDM system,and the authentication is performed to realize the identity detection in the physical layer.This method can achieve one-way or bidirectional static authentication,which can be well applied in the fading mobile scene.The main work and innovation are as follows:1.The multipath delay variation characteristics of the wireless channel are quantified and analyzed from two perspectives of multipath delay variation and multipath delay difference,respectively,and the similarity processing of multipath delay is proposed using the characteristics of delay variation.It improves the efficiency of authentication detection and simplifies the complexity of the algorithm.2.Based on the characteristics of time-varying channel,a new physical layer authentication scheme based on multipath time-delay feature is designed to better solve the authentication problem when the user is in a moving state.It can track the dynamic change of the multipath time delay in real-time.When the receiver is in the mobile state,the multi-path characteristics of the channel can be detected well by adjusting the dynamic factor to achieve identity authentication.3.In the physical layer,machine learning SVM classification algorithm is introduced to train the physical layer channel delay characteristics,and a new method of wireless physical layer authentication based on SVM algorithm is proposed.It can improve the resource utilization rate of physical layer and solve the problem of low recognition rate under low SNR.Compared with the traditional authentication scheme,the authentication performance of the scheme is significantly improved and the authentication efficiency is also good when the multipath delay information changes.