Research On Resource Allocation In Ultra Dense Networks

With the rapid development of mobile communication technology,the 5th generation mobile communication technology(5G)which could meet the application demands will be widely applied in people's daily life.It will will innovate in spectrum efficiency,energy efficiency,and cost efficiency,and further expand the development space of mobile communication industry.Ultra dense network(UDN)which has deployed a large number of low power wireless access nodes densely and randomly in hot spots,has achieved sufficient development in recent years and has become a key technology for improving spectrum efficiency and network capacity.However,as the deployment density of low power nodes increases,the amount of information that needs to be exchanged becomes enormous.Various interference in the communication environment also increases,resulting high complexity of processing.The huge energy consumption brings about unprecedented challenges to operation and management of wireless communication networks and violates the inevitable requirements of sustainable development of green communication and low carbon life.Therefore,exploring a more rapid and efficient resource allocation strategy has become the main research direction for the development of the next generation mobile communication system.In this thesis,according to the related theories of traditional wireless resource management technology,we mainly studied how to optimize network throughput and energy efficiency in UDN.The specific work is as follows:(1)In order to improve spectral efficiency and capacity of the system,a cluster priority based throughput optimization resource allocation scheme is proposed.This scheme studies the resource allocation in UDN.First,clustering is performed on the basis of coloring theory which will effectively suppress the interference in the system.Then sub-channels are successively allocated according to cluster prioritiy.This method theoretically guarantees fairness among users and utilization of spectrum resources.Finally,in order to maximize the system throughput,the convex optimization related theory is used to perform power allocation under the constraint of basic conditions.The simulation results show that the proposed scheme can allocate resource more reasonably and improve the overall performance of the system.(2)In order to improve the energy efficiency of the system,an energy efficient sub-channels and power allocation scheme is proposed.Based on the minimum data rate of users,the maximum transmit power of base stations and other constraints,the energy efficiency is modeled as a mixed integer nonlinear programming problem.Since the efficiency of exhaustive search method for calculating the global optimal solution is low,this thesis reduces the solution space by introducing a binary variable.Then the maximum achievable rate based algorithm and Lagrangian dual are used to allocate resource.The simulation results show that the proposed scheme can effectively reduce energy consumption,improve energy efficiency and suppress network interference.Simultaneously,it can converge quickly.