Research On Base Station Sleep Mechanism Based On Spatial Poisson Point Process In Heterogeneous Ultra-dense Networks

With the rapidly increasing number of smart devices,the limited network capacity and ever-increasing service requirements have become main problems in mobile communications.In order to cope with the ongoing increasing mobile data demand,the ultra-dense network is proposed in the 5th generation mobile communication(5G).By deploying a large number of low-power small base stations in conventional macrocell networks,high data service for mobile users is provided.However,the deployment of heterogeneous ultra-dense networks has brought about new challenges,especially the sharply rising energy consumption of network.Therefore,how to effectively reduce energy consumption of network is one of the main problem in heterogeneous ultra-dense networks.Using base station sleep mechanism can not only improve the utilization of network resources,but also effectively reduce the energy consumption of network.Thus,this thesis studies the mechanism of base station sleep in heterogeneous ultra-dense networks.Firstly,the necessity of the appearance of heterogeneous ultra-dense networks is introduced.On this basis,the current research situations of green communication are elaborated.This thesis mainly describes the technique and the relevant mechanisms of base station sleep and introduces the application of the Spatial Poisson Point Process(SPPP)in wireless network.Secondly,in light of the problem that the energy consumption caused by the ultradense deployment of small base station in heterogeneous ultra-dense networks is more,a joint strategy based on small base station sleep and spectrum resource allocation is proposed.Using SPPP,the coverage probabilities of base stations and the average ergodic rate expressions of mobile users are derived in closed access and open access.In addition,by adjusting the two parameters of the spectrum allocation coefficient and the small base station active probability,the problems of maximizing the coverage probability and minimizing the energy consumption of the whole network are solved.Simulation results show that the proposed strategy can significantly reduce the energy consumption of network and ensure the quality of communication of mobile users.Next,in light of the problem that the rate requirement for mobile user communication after small base station sleeping is not guaranteed,a small base station sleep algorithm based on load transfer is proposed.It considers the downlink and uplink traffic load.At the premises of meeting the service requirements of mobile users,the impact of each small base station sleep on the network is calculated.Then,the small base stations with smaller impact on the network switch to sleep mode to reduce energy consumption.The simulation results show that the proposed algorithm not only guarantees the data rate requirements of mobile users,but also saves network energy to a maximum.Finally,the conclusion and future research works are given.