Research On Energy Efficiency In Heterogeneous Cellular Network

With the rapid development of wireless communication and the popularization of intelligent terminal equipment,there has been an explosive growth of data traffic.Heterogeneous cellular networks,as a technology that can improve system capacity and improve edge coverage,have drawn wide attention from industry and academia.Heterogeneous cellular networks deploy different low-power base station nodes within the coverage of a macro cell,and increase the network capacity and coverage through intensive deployment of nodes.However,the intensive deployment of base station nodes has resulted in a continuous increase in energy consumption,which has a huge economic and environmental impact.In order to save energy and achieve green communication,the energy efficiency in heterogeneous cellular networks is studied in this paper.Firstly,the impact of micro base stations density on the energy efficiency of the system is studied.Heterogeneous cellular networks are modeled using the homogeneous Poisson point process,and then the expression of the coverage and reachable rate of the system is derived under the Rayleigh channel environment,and the closed form expression of the energy efficiency is derived,and then optimize the density of micro base stations by convex optimization algorithm.The simulation results verify the correctness of the theoretical analysis.Based on this study,the problem of resource allocation based on energy efficiency in heterogeneous cellular networks is studied.In order to reduce the complexity of problem analysis,the resource allocation problem is divided into three sub-problems: base station allocation,subcarrier allocation and power allocation.For the base station assignment sub-problem,the criterion based on the average SINR of all the sub-channels is used to determine the association between the user and the base station.After the allocation of base stations is determined,a subcarrier adjusted proportional fairness algorithm is proposed to obtain the sub-carrier allocation based on the traditional proportional fairness algorithm.After the subcarrier allocation is determined,for the power assignment sub-problem,the objective function of fractional form is first transformed into the subtrahend form by using the idea of Dinkelbach to solve the fractional programming,and then the optimal power allocation is obtained by Lagrange's duality and subgradient method.The simulation results verify the effectiveness of the algorithm.