Research On Simultaneous Wireless Information And Power Transfer In Amplifying-and-forward Relay Network

With the rapid development of wireless communication technology,relay technology has the advantages of improving the system gain,expanding the coverage and low cost.At the same time,the problems of energy consumption of wireless communication system and the problems of the endurance of wireless devices are also increasingly prominent.In order to take a low-carbon,environmentally friendly,and sustainable development,the more "green" communication technology has become an urgent need to improve the system performance and economic benefits.Under the guidance of the concept of green communication,the simultaneous wireless information and power transfer(SWIPT),which can transmit information and energy at the same time,becomes an effective method to solve the energy bottleneck of wireless communication devices.Therefore,the combination of the SWIPT technology and the relay network has gradually become a research hotspot.In this paper,we study the problem of SWIPT in the amplify-and-forward relay networks.Based on the establishment of a suitable mathematical model,we take the minimum system mean-square-error(MSE)as the optimization objective,and focus on solving the problem of joint beamforming in relay networks under the power constraint conditions and the energy harvesting conditions.According to the specific optimization problem,with the help of convex optimization knowledge,we will put forward the corresponding optimization schemes,and implement the relevant algorithms through the simulation tools to verify their performance.The main research contents are as follows:First,the research status of the SWIPT in amplify and forward relay network is analyzed,the main problems of this paper are presented,and the convex optimization theory is introduced.Based on the system model of MIMO technology and beamforming technology,the related knowledge of amplify and forward relaying network is introduced,and the corresponding relay network models are analyzed.At the same time,the SWIPT technology is introduced,and its key technologies are studied,and the system models are proposed.Then,the optimal design scheme of relay network with SWIPT is proposed to minimize the total mean square error as the optimization objective,and the two different iterative optimization algorithms are proposed by using the method of semi-definite programming to meet the constraint conditions of relay power constraint and source node energy harvesting constraint.Thirdly,we established a mathematical model of the system model,which is based on the relay node with SWIPT in the relay network.The optimization objective is to minimize the mean square error of the system.At the same time,two kinds of optimization schemes with different complexity are proposed by using the successive convex approximation algorithm under the power constraint conditions of the source node and the relay node.Finally,according to the corresponding optimization schemes,we build the corresponding simulation platforms,and realize the proposed optimization algorithms.Through numerical analysis,we verify the effectiveness of the proposed algorithms.