Research On D2D Communication Based On Capacity Maximization

With the rapid development of mobile multimedia communication technology,the Internet and cloud computing technology and other emerging technologies came in our sight,and become the many people's essential dayily needs,the Internet technology began gradually development from the PC to the mobile phone terminal,mobile Internet technology has become represent the general trend.As wireless communications carriers,the cellular network will also usher in a new challenges.The popularity of mobile phone,tablet computer and other mobile devices,mobile users demand for bandwidth is in rapid growth.However,the bandwidth is limited in cellular network,how to ensure the growing needs of the mobile users for the business demand with limited bandwidth,it become the communication problems that need to be solved in the future.then the Device-to-Device(D2D)technology came into being.In the process of the Device-to-Device communication technology,the data for communication directly from the sending users end transmission to the user receiver.The number of channels in the communication process to reduce by two to one,so that saving bandwidth.Usually the equipments of using D2 D communication is closer to the base station,so it can reduce transmit power from user terminal in a certain extent,it also can reduce the power consumption from user terminal in a certain extent.In addition the D2 D user and cell user use the same frequency band resource in the cell network,because of D2 D communication has lower transmit power,the D2 D user can reuse the same frequency band resource from cell network user to some extent.To enhance the utilization rate of the cell resource more and more,and increase the total cell capacity.So introduce D2 D communication technology into the cellular network can get a higher transmission rate.A greater rate of network bandwidth and better quality of service.This paper studies the selection of forwarding user problem for multicast in single cellular network scenario,and the problem of D2 D user reusing frequency band resource and how to allocation these resource in the same channel cellular network.At first,this paper studies the resource allocation in cellular user and D2 D user,and reusing the resource in single cell scenarios.In the traditional reuse of resources allocation scheme,according to the colored theory to let D2 D user into deffenent cluster with different geographical locations,each D2 D communication cluster use a set of multiplexing bandwidth resource.On this basis,this paper puts forward based on fuzzy C-means(FCM)algorithm and greedy algorithm resource allocation scheme,first through the FCM algorithm to divided D2 D user into different clusters.then use greedy algorithm to calculate the reuse resources of D2 D according to the D2 D user and the cellular user distance,and simulated this resource allocation scheme is proposed in this paper,and simulated resource allocation based on coloring theory.Compared to the scheme,the results prove the effectiveness of the proposed scheme.Compared with the resource allocation scheme of the coloring theory,the resource allocation scheme based on FCM algorithm and greedy algorithm can effectively improve the total capacity of the system.In addition,this paper studies the hybrid cellular network with D2 D communication multicast service clustering scheme.In traditional multicast relay user selection scheme,According to the algorithm calculate distance threshold between D2 D multicast relay user and base station,and through the threshold to select the user's communication mode,and calculate the D2 D multicast relay users.In this paper on the basis of improvement,proposed that select D2 D multicast relay users through the kmediods algorithm.And according to the distance from the base station to determine user's communication mode in the rest of the user.Simulation shows the comparison of capacity between multicast group communication with k-mediods algorithm that we proposed and the traditional SINR threshold algorithm in this paper,the results show that the algorithm we proposed have effectively improvement for the system capacity of the cell.Finally,the paper summarizes the research content of the paper,and analyzes the advantages and disadvantages of the proposed scheme that we proposed,and looking forward the future research direction.