Research On Physical Layer Security Of D2D Anti-eavesdrop Communication Based On Game Theory

With the rapid development of domestic mobile communication services,the demand for high-speed,high-quality,low-latency services is increasing,but limited spectrum resources have become the most important factor restricting the performance of cellular systems.The rise of big data services and the influx of more intelligent terminals have caused even greater load on the base stations.As a new communication concept in the cellular network,D2 D effectively alleviates these problems and has many advantages,such as reducing transmission delay,saving spectrum resources,reducing base station load,improving spectrum efficiency and so on.Communication security is a prerequisite for the success of D2 D services.Users of the wireless network are more susceptible to eavesdropping due to the natural broadcast characteristics of the wireless channel.The traditional encryption scheme is based on the high complexity of the algorithm.However,due to the energy limitation of the mobile terminal,it is impossible to support high-complexity encryption and decryption operations for a long time,and with the development of computing performance,the eavesdropper has stronger computing power,and the traditional Encryption solutions are facing increasingly developed challenges.Physical layer security,as an alternative to traditional encryption schemes,has received widespread attention in recent years.Based on information theory,the physical layer security uses the physical characteristics of the wireless transmission medium to improve the channel conditions of the legitimate channel and the deteriorating eavesdropping channel through appropriate coding and signal processing techniques,thereby improving the interception rate of the eavesdropper and make it impossible to obtain legal information from the physical layer.Based on game theory,this paper studies the anti-eavesdropping strategy of D2 D communication under cellular networks.When there is an eavesdropper in the cell,the D2 D user improves the security performance through the interference assistance of the CUE user.The CUE user does not provide help for free for "selfishness",and proposed the physical layer security method based on bargaining game to solve the association cooperation and conflict of interest between the D2 D user and the CUE user.;then,for the problem that D2 D users are in a game disadvantage in the single-interference node scenario,the multi-interference node is further introduced,and the physical layer security method based on the Stackelberg game is proposed.Main tasks as follows:(1)Propose a physical layer security method based on bargaining gameWe simplify the cell into a form consisting of D2D-to-CUE pairs,pairing D2 D users in the cell with CUE interfering nodes,that is,each D2 D user is equipped with a CUE interfering node to provide interference services.We use bargaining Game theory models the scene.In the bargaining game,both D2 D users and CUE interfering nodes want to maximize their own profits for selfishness.A number of evaluation criteria are introduced in this paper.The theoretical space of D2D-to-CUE pair D2 D users and CUE interference nodes is obtained through theoretical analysis.Two algorithms,Non-Step and Step-Contained,are proposed to solve the game problem based on the strategy space.In the Non-Step algorithm,we design a comprehensive utility function to represent the total benefit of the game when the two sides reach a consensus.This function reflects that the total benefit under the consensus state is always greater than the total benefit under the unconsensus.In addition,we also introduce a balancing function in the algorithm so that the benefits of D2 D and CUE do not create excessive gaps.In the Step-Contained algorithm,we take the time factor into account and make the iteration step of the algorithm affect the total benefit of both sides of the game.Therefore,we design a attenuation function acting on the total benefit of the D2D-to-CUE pair.The more the number of iterations,the more the attenuation is.The simulation results show that the algorithm enables the two parties to reach a faster transaction.(2)Propose a physical layer security method based on the Stackelberg game in a multi-interference node scenarioIn view of the situation that D2 D users are in a disadvantage position in the game during the single friendly interference node scenario,this chapter introduces multiple interference nodes,and considers the distance factors between the interference nodes and the eavesdropper,so that the distance affects the pricing of the interference nodes,and redesigns the benefit function of the interfering node to avoid the vicious price competition and underpricing between nodes.The proposed scenario is modeled by the Stackelberg game,and the game relationship between D2 D users and friendly interfering nodes is analyzed.The mathematical simulation results show that the D2 D users in this scenario obtain greater autonomy and significantly improve the D2 D security capacity.