Analysis Of User Rate And Energy Efficiency For Hetnets Under Poisson Cluster Process

In the future network communications,Heterogeneous cellular networks(HetNets)consist of different tiers of base stations(BSs)to meet the everincreasing mobile traffic demand.Energy efficiency and Spectrum efficiency have now been considered as key performance indicators for future wireless networks.Therefore,the target of this thesis is to analyze the spectrum efficiency and energy efficiency of HetNets and propose a solution for minimizing energy consumption.The modeling methods for HetNets based on stochastic geometry is effective for analyzing HetNets.Due to the random deployment of BSs,Poisson point process(PPP)is often used to model the BS distribution.However,low power small cells are usually clustered around the popular areas,and it is not of uniform distribution,while PPP can not reflect such a feature.Investigating a more accurate model therefore becomes imperative.To this end,we in this thesis consider base station cooperation and analyze user rate and energy efficiency of HetNets based on a more accurate model(e.g.Poisson cluster process(PCP)).A calculable formula for the average data rate and its approximated closed form are derived.Based on this closed form,a power minimization solution with certain spectral efficiency constraint is proposed,and then the optimal cooperation radii are derived.Furthermore,we analyze spectral efficiency assuming a limited number of cooperative BSs in a two-tier network modeled as PCP,and propose a range extension(RE)scheme based on coordinated multi-point(CoMP)transmission,which can better balance the load of macro BSs.Simulation results show that the performances of Poisson cluster process is poorer than that of Poisson point process.From the perspectives of power optimisation,the proposed optimisation solution determines the optimal values for each tiers cooperation radius.The optimal value and upper bound curves verify that the closed form of spectral efficiency is effective.Finally,simulation results indicate that the number of associated base stations should be limited to an acceptable level,and the proposed range extension cooperation can relieve the loading of macro BSs and greatly improve the energy efficiency.