Energy Optimization For Heterogeneous Network

The rapid development of mobile internet enriches people's life,but also puts forward higher communication needs.Different types of cellulars are deployed to fulfill the demand of people.At the same time,increased number of base stations bring huge energy consumption inevitably.Considered the economic,environment and other factors,the concept of green communication is slowly accepted by people.Reduce the energy consumption of cellular networks has become a research hot spot.Based on this background,this thesis studies the energy consumption of heterogeneous cellular networks from the perspective of coordinated multiple points technology and cell sleeping mechanism.This thesis studies a user-centric base stations cooperation strategy which the base stations located within the cooperation radius serve the target user together.First,we build the system model by homogeneous poisson point process,then derive the ergodic rate expression for cooperation radius.Then because the energy consumption within the cooperation set and the ergodic rate of target user rate are both related to the cooperation radius,we can construct the optimization problem of energy consumption within the cooperation radius with known target user rate demand.Finally we obtain the optimal cooperation radius with lowest energy consumption based on a bisection algorithm.The simulation results show that,compared with homogeneous cellular networks,the cooperative strategy in this paper has a better performance in heterogeneous cellular networks.Cell sleeping technology reduces the energy efficiency of cellular networks by selectively turning off the base station.Based on the above system model,we study a small cell random sleep strategy continuously.While meeting the target user rate needs,small cells which participate in the cooperation sleep with an appropriate sleeping ratio.First,we derive the ergodic rate expression for sleeping ratio.Then we construct a optimization problem with known target user rate demand to obtain the optimal sleeping ratio with certain cooperation radius.In order to analyze the lowest energy consumption in the cooperation set,we construct a optimization problem of energy consumption and proposed a joint optimization of the cooperation radius and sleep ratio algorithm to solve the optimization problem.Finally,we simulate to analysis the lowest energy consumption within the cooperation.