Resource Scheduling Optimization In Energy Harvesting Wireless Communication Network

With the expansion of communication network,the energy consumption of the communication industry is increasing heavily.Due to the increasing scarcity of energy sources,how to achieve the goal of energy saving has become a focus of the communica-tion industry research.Energy Harvesting(EH)technology,which has characteristic of deployment flexibility,can provide constant pollution-free energy for network devices and become the frontier technology in the green communication network.Meanwhile,as a non-contact power transmission technology,Wireless Power Transfer(WPT)tech-nology also plays an important role in promoting the utilization of spectrum and en-ergy saving.However,the EH communication network has many weaknesses,such as unstable energy sources,limited storage capacity,and the randomness of the wireless channel state,which bring many challenges to the scheduling and allocation of system resources.In order to improve the energy efficiency and guarantee the quality of service in data transmission,considering the stochastic factors in EH communication network,the problem of system resources scheduling and allocation is analyzed,modeled and op-timized by using stochastic optimization theory in this dissertation.The specific work is as follows:1.The problem of causally scheduling wireless power transmission in a point-to-point wireless power transfer system is studied.The receiver maintains its operation by harvesting the wireless energy transmitted by the transmitter.Under the constraints of random variation of Channel State Information(CSI)and limited transmission comple-tion time,selecting appropriate time slots,which have good CSI to execute power trans-mission task,can reduce energy consumption and improve energy transfer efficiency.The scheduling problem is converted into a Markov Decision Process(MDP).Consid-ering the knowledge of current CSI and statistical information about future CSI,the algorithms calculating decision thresholds for non-interruptible and interruptible task are derived respectively by using stochastic dynamic programming method.With these thresholds,the wireless power transmission scheduling strategy is designed.Numerical simulation results verify the performance of the proposed policies.2.Under the condition of limited energy,the problem of Scalable Video Cod-ing(SVC)layer allocation in a multiuser EH communication system is investigated.In the process of SVC video transmission,not only the arrival of energy is random,but also the CSI of each receiver at different time slots is randomly changed.Under these stochastic conditions,in order to ensure the continuity of SVC video transmis-sion and the fairness of video layer allocation,this thesis models the allocation prob-lem as a constrained transmission utility maximization problem.Based on Large De-viations Principle(LDP),an Online Measurement-based Video Layer Allocation Strat-egy(OM-VLAS)and an Online Measurement-based Heuristic Video Layer Allocation Strategy(OM-HVLAS)are proposed.Finally,the effectiveness of the proposed strat-egy is demonstrated by simulation experiment which based on the real SVC video se-quence.3.The control protocol of microwave wireless energy transmission system is de-signed.(1)According to the different stages of information and energy interaction,the statuses of transmitter and receiver are defined.On the basis of these statuses,this dis-sertation designs an interaction method for information and energy,which can realize the request,establishment.and release of wireless power transmission through wireless information interaction.(2)In order to adjust the transmission power effectively,a PID control method based on iterative learning is proposed.(3)A multi-receiver scheduling method is presented to realize the orderly management and scheduling of the receivers.