Resource Allocation And Energy Cooperation Of Green Hetnets

With the rapid development of mobile Internet and the explosive growth of smart terminals,various mobile application services have emerged,causing exponential growth of wireless data traffic.Energy consumption caused by wireless network access also increases,causing energy tightening,economic issues and environment problems.At the same time,the users' wireless network communication performance requirements are getting higher and higher.Based on this,a green heterogeneous network formed by cells with different power consumption,different coverage and energy harvesting is receiving more and more attention.Heterogeneous networks(HetNets)could provide high-speed,high-performance,energy-efficient wireless access.However,densely deployed HetNet also faces following technical difficulties: 1)the randomly harvested new energy can not provide stable power for base stations,thus limiting the network performance;2)the interference between base stations and the energy allocation problem lead to the compromise between user service quality and network energy consumption;3)the energy cooperation between base stations is affected by the temporal and spatial characteristics of new energy sources.Therefore,in order to improve network efficiency,reduce power consumption and improve customer service quality,considering the above challenges this article proposes following methods.1)Reduce grid energy consumption based on user association and energy cooperation.As renewable energy is intermittent and randomly distributed,it is difficult for energy harvesting enabled networks to reliably supply the time-varying mobile traffic.Based on HetNets with hybrid energy supply,energy sharing and load shifting are considered at the same time.Load shifting problems and energy sharing issues are coupled with each other which makes the optimal problem complicated.First,the user association problem with energy cooperation to minimize the grid energy expenditure of HetNets is investigated.Then,by using greedy decomposition,this problem is converted into two sub-problems which are energy cost aware user association(UA)subproblem and energy cooperation subproblem.By using relaxing,Lagrange dual decomposition,UA subproblem can be solved.A many-to-many matching algorithm is used to solve energy cooperation subproblem.Finally,simulation results show the effectiveness of the proposed algorithms and demonstrate that the proposed algorithm is the most on-grid energy saving algorithm compared with existing schemes.2)For hybrid energy powered HetNet,the problem of resource allocation with user delay constraint and cross-layer interference limitation is studied.For hybrid energy powered HetNet,the resource allocation problem with user delay and cross-layer interference limitation is studied.Since two layers of HetNet adopt the same frequency deployment mode,there exists HetNet cross-layer interference problem.Based on this,this paper takes the problem of dynamic energy efficiency resource allocation in two-layer heterogeneous cellular networks with delay awareness and interference awareness into consideration.In this problem,the macro base station adopts grid power supply,and the micro base station adopts a hybrid energy supply mode.We establish a joint optimization problem that considers flow control,resource allocation,and new energy scheduling to maximize the per-hour energy efficiency of small cell users.Considering the random arrivals of new energy and mobile user load data which are dynamically changing in both time and space,an energy efficient resource allocation algorithm with delay awareness is proposed based on Lyapunov optimization.Under limited capacity of data cache and storage device,it is proved that the proposed algorithm could infinitely approach the optimal solution.Finally,the simulation results show that the proposed algorithm is more efficient,and once again proved the theoretical analysis.3)For hybrid energy powered HetNet,the problem of resource allocation and energy cooperation with cross-layer interference limitation is studied.In this case,two-layer HetNet deployed in the same frequency has cross-layer interference.Smart grid is introduce to enable energy cooperation between base stations,thus utilizing inhomogeneous new energy sources more effectively.Based on aforementioned reasons,we consider the problem of dynamic energy efficiency resource allocation in two-layer heterogeneous cellular networks with interference awareness.We establish a joint optimization problem that considers radio resource allocation,new energy dispatch,and energy cooperation to maximize the per-hour energy efficiency of small cell users.By using Lyapunov optimization method,we design online radio resource allocation algorithm,new energy scheduling and cooperation algorithm.Then,the theoretical analysis proves the stability of the network.Finally,the proposed algorithm is verified by numerical simulation.