Experience-aware Spectrum Access Research Of Device-to-Device Communication

In recent years,the number of mobile terminals has grown rapidly,and users' wireless access requirements have also rapidly increased,resulting in spectrum resources allocated strain,low utilization of authorized spectrum and unbalanced spectrum utilization.With the rapid development of wireless communication technology,the communication method which depends on the base station as a communication relay has shown drawbacks in terms of flexibility,in order to solve the special needs of various business types in real-time and reliability,D2D(Device-to-Device)communication technology comes into being and becomes one of the key technologies of 5G.The technical feature of D2 D communication is that users within a certain distance under a cellular network can communicate directly,instead of transmitting through a base station and the key problems to be solved is that the mutual interference between cellular users and D2 D users,as well as the design of a reasonable spectrum access and sharing strategy to enhance the overall performance of the network.Game theory is an effective tool to study the strategic choices among multiple decision makers with competing relationships.The spectrum access problem in D2 D communication is just a matter of strategic choices.Therefore,the introduction of game theory to D2 D communication can effectively analyze the spectrum access problem,the main study of this paper is the spectrum access strategy in the two communication modes of D2 D communication based on user experience and game theory approach is adopted.The main work and innovations of the thesis are as follows:1.In order to guarantee user satisfaction in D2 D communication,a multi-channel spectrum access strategy based on interference constraints and user experience in the opportunity access mode is proposed,and a game theory approach is adopted to solve strategic choices of the spectrum access under this mode.The idea is to introduce interference constraints to reduce system interference,and to introduce a satisfaction function to measure the user experience effect,based on this,the game problem between D2 D users is modeled as the selection problem of optimal channel set with the goal of maximizing revenue.First,through theoretical analysis,it is proved that the modeled game problem is a precise potential game that makes the potential function maximum,that is,the existence of the optimal solution.Then the simulation verifies the effectiveness of the proposed strategy.The results show that the introduction of user satisfaction and interference constraints significantly reduce the interference level of the entire network,while improving the users' satisfaction and fairness as well as the overall performance of the system by reason of considering D2 D users transmit in multiple channels :2.In order to further improve the spectrum efficiency in D2 D communication,the spectrum access strategy in the shared mode is studied.The idea is that D2 D users share the spectrum resources with the cellular users without exceeding the interference threshold of the cellular users,and at the same time achieve their own satisfaction requirements.Based on this idea,using the relevant knowledge of the alliance game,a game problem is established with a goal of the optimization user experience of D2 D users accessing the available channels to seek the optimal channel allocation scheme.Simulation results show that the proposed channel allocation algorithm based on user satisfaction can achieve a better user experience than the channel allocation algorithm with minimal interference spectrum access and random access allocation algorithm.