Optimization Of Massive-MIMO Based Wireless Energy Powered System

The battery capacity is considered as one of the most important factors limitting the development of wireless communication.However,the development of battery capacity in last twenty years is extremely slow,a lot of technical schemes to improve the capacity of the battery is almost in the research stage and they can not be applied to practice in a short time.Therefore,the wireless energy transfer is considered to cut the last cable of wireless communication,it is an important technology and has great prospect to achieve"true"wireless".On one hand,in order to improve efficiency and distance of wireless energy transmission,massive multi input multi output(Massive-MIMO)antenna is employed in this thesis.First of all,the research status of wireless energy transmission is discussed.Then,the framework of energy harvesting and circuit model of energy harvesting terminal is proposed.Combining massive-MIMO with wireless energy transmission,the characteristics of wireless energy transmission and wireless information transmission is summarized.Besides,the framework and transmission model of energy and information hybrid transmission is derived in this thesis.On the other hand,we study the downlink of Massive-MIMO based wireless energy transmission.Because most researchers do not utilize the characteristics of Massive-MIMO and only adopt linear energy harverting model,the characteristics of Massive-MIMO are taken into consideration and a non-linear energy harvesting model is employed in this thesis.With constraint of transit power,the total harvesting energy index and the minimum harvesting energy index of all users are proposed to quantify the performance of this system.To satisfy different requirements of different scenarios,two optimal combination coefficients are proposed.In the last part of this thesis,the scenario is extended to wireless information and energy supply control systems.With centralized massive-MIMO and imperfect channel state,hybrid energy and information on downlink transmission are studied.Compared with the tranditional control systems,control cost is proposed as a metric to quantify the performance of this control system.To minimize the control cost of wireless information and energy supply control systems,the optimal slot and power allocation is derived.