Research On Physical Layer Security Of Wireless Fading Channel

Compared with the wired communication networks,the advantages of wireless communication are low cost,short networking time,more suitable for the laying of harsh environment,strong access and convenient maintenance.Therefore,it has been vigorously promoted in recent years.The openness and portability of wireless communication determine that it brings convenience,however,at the same time,it is more vulnerable to interference and eavesdropping from other communication entities.The traditional anti-eavesdropping method is to encrypt in the network layer and above of the seven-layer network The complex key algorithm can bring the difficulty of cracking,so as to ensure the safe transmission of data.However,with the rapid development of computer technology,the super computing power of eavesdropping terminal makes it possible to decrypt the information.In addition,in mobile environment,the legal terminal is often small in size,the weak processing ability will increase the network signal transmission delay.Therefore,the physical layer security technology emerges as the times required.The physical layer security uses the fading of the channel itself to achieve the effect of anti-eavesdropping by increasing the security capacity.It does not need complex encryption and decryption algorithm,the theoretical basis is Shannon's formula of channel capacity and Wyner's triangle eavesdropping network model.Physical layer security is an effective supplement to the traditional algorithm,and has been paid attention by a large number of scholars in recent years.This paper focuses on the theory and performance of physical layer security of complex fading channels.?-? shadowed fading channel is a kind of composite channel with generalized fading.It can describe both direct path non-uniform scattering and shadow fading at the same time.When its shape parameters are different,it can be transformed into Rician,Gamma shadowed,unilateral Gaussian,Nakagami-m and ?-? distribution.Therefore,?-? shadowed fading can simulate many real communication scenarios,such as Internet of things communication,underwater communication,5G and satellite communication,etc.it is necessary to discuss the channel security.The related research results are as follows.Firstly,the security performance of ?-? shadowed fading channel is studied firstly.In this paper,the secrecy of the classical Wiener model of ?-? shadowed is studied.The closed polynomials of SOP and SPSC are derived and simulated.Secondly,the security performance of SIMO system based on ?-? shadowed fading is explored.As a result,the transmission efficiency of Simo is not increased through the construction of a large number of spectrum diversity technologies,which can also improve the transmission efficiency of practical transmission infrastructure.The accurate and approximate closed polynomials of SOP and SPSC are derived and simulated.The simulation results reveal the factors that improve and damage the safety performance of the system.The security of SIMO system on ?-? shadowed fading in active eavesdropping scenario is developed.Active eavesdropping refers to that the eavesdropping terminal initiates eavesdropping actively,so that the sender can obtain the channel state information(CSI)of the eavesdropping channel through multi-channel estimation and other methods.In this situation,the average security capacity(ASC)is a more suitable evaluation metric.Therefore,the closed polynomial of ASC is derived and simulated.Thirdly,the security performance analysis of relaying SIMO systems is completed.In the system model,the relay node adopts the way of decoding and forwarding(DF),and the channel of each link is subject to ?-? shadowed fading.Due to the existence of DF relay and multi antenna reception,the common derivation methods of SOP and SPSC formula will become more complex.Therefore,this paper proposes to divide the calculation of SOP and SPSC into four combinations according to the definition of secrecy outage capacity and the difference of antenna number between legitimate end and eavesdropping terminal.and then combine them to obtain the closed theoretical SOP and SPSC.Moreover,the influence of channel parameters and antenna number on system security is analyzed and summarized through the curves of statistical simulation and theoretical simulation.Fourthly,this paper analyzes the security of multi-eavesdropping cooperative single transmitter multiple receiver network in cognitive radio network.And deduces the theoretical analysis polynomials of SOP and SPSC in the underlay cognitive radio systems under the single transmit multiple receive situation.Moreover,the channel environment to improve and reduce the system security performance are analyzed.To sum up,the main content of this paper is to model and analyze the physical layer security performance of wireless fading channel networks.Combined with different strategies,the closed expression of theoretical security performance index under different communication system models are deduced,and the method of improving system security is obtained through simulation.When the channel parameters and shape parameters of the actual scene explored in this paper are determined by measurement,the evaluation of its security performance can be determined by the following theoretical analysis results.Therefore,the research results of this paper have good theoretical reference significance for the analysis and design of the actual scene.