The Design And Development Of Simulation Platform And Study On Resource Allocation For D2D In Cellular Network

Mobile traffic for wireless communications has experienced tremendous growth over the past few years. The local data sharing service has been greatly increased. The cell service mode centered on the base station has obvious limitations in dealing with the local data sharing service. Traditional cellular communication takes the base station as the central node, all data services are obtained from network through the base station, which greatly limits the development of the local data sharing service. Therefore, a device-to-device (D2D) technology is proposed,which is suitable for the local data sharing service development and perfectly integrating with the traditional cellular mode.D2D technology refers to the adjacent terminals which are in close range can communicate with each other through the direct link without forwarding by central node (i.e. base station).D2D technology is introduced into the authorized frequency band of the cellular system, in which D2D users carry on the direct communication by multiplexing cellular spectrum. The introduction of D2D expands the network coverage, improves spectral resource utilization and system capacity.Firstly, the thesis introduce the basic concepts, three communication modes, and working flow of D2D technology. The time-frequency resource structure of D2D communication and the application scenario of D2D technology are summarized. The mode of wireless resource management for D2D is expatiated from three aspects: mode selection,resource allocation and power control. The research status of resource allocation strategy is analyzed and summarized in detail.Secondly, the thesis designs and achieves D2D system level simulation platform. First of all, the overall design of the platform,including demand analysis and the overall architecture design. Then expatiates the concrete implement of each module of the simulation platform, including the initialization module, the business model module,the resource scheduling module and the interference calculation module.In addition to the realization of D2D basic communication module, in order to verify the D2D resource allocation strategy for simulation, the platform adds the content theme module, D2D user interest degree, and the resource allocation strategy module is designed at the base station. At last, the function verification of the platform is carried out.Finally, the thesis studies the resource allocation strategy of D2D communication in two steps. For the two steps of device discovery and data transmission in D2D communication, the D2D user pairing strategy based on social distance and grouping resource reusing strategy based on global interference analysis are proposed respectively. The concept of user social distance is established according to the degree of user's interest in the content. Based on the analysis of social distance's impact on system content hit rate, We proposed a D2D users pairing strategy of pairing on social distance. After pairing of D2D users, the resource allocation strategy of cellular D2D grouping resource reusing strategy ,which is based on global interference analysis ,is proposed to maximize the number of D2D users being accessed in the cellular system. Combing heuristic iterative algorithm and interference threshold secondary discrimination to obtain the final resource distribution results. Simulation results show that the proposed pairing on social distance strategy and grouping resource reusing strategy can effectively improve the content hit rate of the system under the information sharing scenario and maximize the number of D2D users accessed in the cellular D2D hybrid network.