Incentive Mechanism For Collaborative Transmission In D2D Network Based On Game Theory

With the development of wireless communication, computational and network technology, higher requirements for security and real-time transmission have been put forward. Especially in recent years, in order to achieve wider range of network coverage, faster data transfer rate,higher utilization rate of energy and spectrum, collaboration communication such as D2D communication is put forward and has been applied to 5G. The introduction of node collaboration makes the network more open and its structure more complex, and communication security faces more threats and challenges.The thesis briefly introduces the research status of D2D communication technology at home and abroad as the research background of our topic. It analyzes the research significance after that.Then the thesis takes systematic survey and summary of the physical layer security scheme and cooperative caching mechanism in D2D networks and introduces the application of game theory in modern communication and network. On this basis, it carries out the innovation and improvement to propose caching cooperative transmission scheme based on Stackelberg game and security cooperation interference scheme based on contract theory. Finally, it describes the work and structure arrangement of the full thesis.The thesis puts forward a cooperative caching incentive mechanism based on Stackelberg game by centering on cooperative caching between D2D users and focusing on how to establish effective D2D links in order to realize the base station traffic offloading. A bi-level model of master-slave game is designed by using the framework of Stackelberg game to synthesize the paying rewards and response time in the network as the utility function to measure system performance, and the existence of the equilibrium of the game model is validated. The simulation results show that the proposed scheme can effectively stimulate the nodes to adjust their cooperation strategy, reduce the load of the base station and improve the content sharing efficiency within the network.Secondly, according to the security transmission requirements of user content sharing and the uncertainty of node channel state, the thesis proposes a cooperative interference incentive mechanism based on contract theory. The incentive mechanism takes full account of the uncertainty of the channel state between different nodes, and classifies the cooperative nodes according the states. At the same time, the Lagrangian operator method is used to calculate the optimal contract set.Theoretical analysis and simulation results show that the proposed scheme can achieve a secure and efficient transmission, and makes it possible to help offload the base station, compared to the ideal situation under information symmetry.