Research On Energy Saving Strategy Inheterogeneous Cellular Networks With Hybrid Energy Supply

In recent years,with the rapid increase of energy consumption in wireless cellular networks,more and more attention has been paid to the introduction of renewable energy into wireless cellular networks.Due to the time uncertainty of renewable energy and the spatial dynamics of mobile users,the research on energy consumption and energy allocation in wireless cellular networks is facing great challenges.This paper focuses on the user association problem and energy cooperation problem in heterogeneous cellular networks with hybrid energy supplies.Firstly,a brief introduction is presented to the related technologies of heterogeneous cellular networks consist of concept,characteristics,energy supply modes,user association and the convex optimization theory used in this paper.Secondly,we investigate the user association problem of heterogeneous networks whose base stations are powered by both on-grid and renewable energy.Then,we formulated a problem,which aims to minimizing the consumption of the on-grid energy.A energy-aware cell range expansion algorithm is proposed to optimize the user association,so as to reducing the on-grid energy consumption and verified by simulation.Finally,we investigate the energy cooperation problem with energy saving to minimize the on-grid energy consumption of heterogeneous networks whose base stations are powered by both grid and renewable energy.Then we use greedy decomposition to convert this problem into two sub-problems which are user association and energy cooperation problem.For the first problem,we implement an optimal offline algorithm by using relaxing,dual decomposition.To solve the second problem,we propose a many to-many matching algorithm based on the optimal solution of the user association problem,and the validity and superiority of the proposed algorithm are verified by simulation.