Energy-efficient Wireless Powered Communication Networks

With the development of antenna and radio frequency technology,wireless energy transmission technology can provide the energy needed for wireless charging to the terminal and effectively solve the problem of limited terminal energy.Wireless energy transmission has a very promising application value and more and more attention.At present,most related researches focus on how to get the maximum throughput of the system.But now that communications devices are exploding,the energy they consume will be a huge test of the environment.In addition,the energy obtained by the device in a wireless way is also limited.Therefore,it is quite necessary to study the energy efficient transmission mode to further realize the environmentally friendly and sustainable development and bring more benefits to the future iot applications.This paper makes an in-depth study on the high-efficiency transmission mode of wireless energy transmission,considering the energy consumption loss of the whole system,the transmitting power of the antenna and the power constraint conditions,and how to allocate resources to maximize the energy efficiency of the system.The main content and research results of this paper include:(1)based on beam forming and time distribution of wireless charging network,considering from the system power station sends a radio frequency signals and the user information in two stages of the energy consumption,by a combined system throughput than on the total energy consumption to measure so users gain energy after sending information of energy efficiency,and to maximize the system energy efficiency.(2)since energy efficiency is defined as a fractional form,which is a non-convex problem,the objective function maximization problem is converted into a parametric subtraction problem by fractional programming.A convex optimization problem with parameter solvable is obtained by introducing a variable.Two different iterative methods are introduced to solve the problem,and the results are verified by simulation.(3)in the optimization of energy efficiency of wireless charging network system,due to the near and far effects,users are not fair.Therefore,considering the quality of service and fairness of users,we propose a multi-objective planning method to maximize the minimum information of each user while minimizing the system energy consumption.First of all,we find the user,the range of the amount of information available to find meet the requirements of the maximum amount of user information threshold,and then solve the problem of minimizing the system energy consumption,by putting a multi-objective into but after goal programming to solve the problem,can not only improve the system efficiency,at the same time ensuring the quality of each user service..