Research On Wireless Pre-storage Technology Based On Small Base Stations

Wireless data traffic,especially the data traffic of videos,has been increasing dramatically in recent years,driven by the increasing capabilities of intelligent terminals.Caching data in the storage of small-cell base stations(SBSs),namely,small-cell caching,is an efficient technology for reducing the transmission latency and mitigating the redundant transmissions while improving the frequency spectrum utilization.However,how to model caching system in stochastic networks and to improve the successful downloading probability and how to make pricing rules and to allocate SBSs are urgently to be solved.This thesis focuses on the above problems,and obtains the following research results:(1)Based on stochastic geometry,SBSs are modeled in the network as a poisson point process(PPP).Then,the probability that mobile users can successfully download contents from the storage of SBSs are derived.The numerical results match the the results of monte-carlo simulation in all scenarios.Then,probabilitistic small-cell caching strategy with optimization of the caching probability is designed.Simulation results show that the method can effectively improve the successful downloading probability.(2)The problems on pricing and resource allocation can be solved within the framework of stackelberg game.SBSs are treated as a specific type of resources.Stackelberg game of single leader can be introduced in small-cell caching system with a network service provider(NSP).Stackelberg equilibrium is analysed under the uniform and non-uniform pricing scheme by solving a convex optimization problem.Simulation results show that the proposed schemes are effective in both pricing and SBSs allocation.(3)In order to fully consider the caching system,stackelberg game of multiple leaders can be introduced in the system with multiple NSPs.Sackelberg equilibrium is investigated to solve the optimization problem in two cases i.e.whether or not the video retailer(VR)has a budget plan on renting the SBSs.Numerical results are provided for quantifying the proposed framework by showing its efficiency on pricing and SBSs allocation.Finally,the paper summarizes the whole work and points out the existing deficiencies.In addition,the prospect of further research is discussed.