The Physical Layer Security Performance Of Massive MIMO Two-way Relay System

The popularity of wireless communication applications stems from its broadcast features,allowing users to access information at any time without geographical restrictions.However,it is also the nature of broadcasting that makes it easy and concealed for eavesdroppers to steal information,making it difficult to secure wireless communications.Therefore,information security has always been a key issue in wireless communications.Traditionally,we have used complex cryptography to achieve secure communication of the system.However,as computer processing power increases,the security of traditional methods is greatly reduced.The wireless communication physical layer security transmission technology is based on the characteristics of the wireless channel itself,and utilizes the concept of security capacity and coding technology to ensure secure communication from the perspective of information theory and greatly improve system security performance.In the large-scale MIMO two-way relay system,it is also important to ensure the secure communication of the system.This paper will study the physical layer security performance of the massive MIMO two-way relay system.The main work includes the following three points.1.Firstly,this paper studies the physical layer security performance of massive MIMO multi-pair two-way relay systems under Rayleigh fading channels.This paper derives the approximate expression of the system reachable security rate.Through this expression,the relationship between the system reachable security rate and the number of relayed antennas and user pairs can be obtained.In addition,for the four typical power allocation schemes,the corresponding system reachable safety rate approximation expression is derived.From the approximate expressions under the four power allocation schemes,the following conclusion can be drawn: when the transmission power of each user or the transmission power of the relay side is proportional to the reciprocal of the number of relay side antennas,the number of relay side antennas The gradual increase of the eavesdropping user's reachability rate gradually approaches zero,while the legal user's reachability rate gradually approaches a certain value,and the system's reachable security rate side is proportional to the number of users.The simulation results verify the accuracy of the corresponding theoretical derivation results.2.Secondly,this paper studies the physical layer security performance of massive MIMO multi-pair two-way relay system under the condition of Rice fading channel.This paper derives the approximate expression of the system reachable security rate.Through this expression,we can get the system reachable safety rate and large-scale fading coefficient,Rice K factor,number of antennas on the relay side,and user logarithm.relationship.In addition,for the four typical power allocation schemes,the corresponding system reachable safety rate approximation expression is derived.From the approximate expression,conclusions similar to those under Rayleigh channel conditions can also be obtained.The simulation results verify the accuracy of the corresponding theoretical derivation results.3.Finally,in view of the difficulty in obtaining accurate channel state information in practical scenarios,this paper studies the impact of imperfect channel state information on the physical layer security performance of massive MIMO multi-pair two-way relay systems.In this paper,the approximate expression of the system reachable security rate is derived.According to the expression,the system reachable safety rate and pilot number,large scale fading coefficient,Rice K factor,relay antenna number and user logarithm can be obtained.Relationship between.For the four typical power allocation schemes,the corresponding system reachable safety rate approximate expressions are derived.From the approximate expression,we still get the conclusion similar to the previous two application scenarios.The simulation results verify the correctness of the corresponding theoretical derivation results.