Resource Optimization Management Based On Simultaneous Wireless Information And Power Transfer In Cooperative Relay Network

With the development of wireless communication technology,the access number of smart devices is increasing rapidly,leading to a shortage of wireless network resources.In order to solve this problem,energy harvesting is regarded as a potential solution to the problem of energy supply.Simultaneous Wireless Information and Power Transfer(SWIPT)provides an effective technical guarantee for information transmission and energy harvesting in wireless communication networks.The introduction of SWIPT to the cooperative relay network expands the communication coverage and extends the battery life of the relay.However,the combination of SWIPT and relay also caused some problems and challenges,such as the trade-off between energy harvesting and rate transmission,and how to solve the complex problems caused by multivariable coupling.In order to solve the above problems,this paper studies the resource optimization in different scenarios based on the relay network with SWIPT.Firstly,a channel model with uncertain channel state information is considered for the fixed relay network with SWIPT.The problem of maximizing the energy efficiency of the secondary system is proposed by jointly optimizing power and subcarrier allocation.The complex non-convex optimization problem is transformed into the convex optimization problem through fractional programming and inexact block coordinate descent method.The standard Hungarian algorithm is used to solve the subcarrier allocation problem.An effective optimization algorithm is designed to obtain the optimal transmission power and power splitting ratio.Simulation results show that the network performance is improved and the energy efficiency of the secondary system is maximized by the proposed algorithm.Secondly,the mobile relay network with SWIPT is studied.Taking into account the characteristics of high flexibility and easy deployment of unmanned aerial vehicles(UAVs),the UAV with energy harvesting is used as a mobile relay to assist communication.In satisfying the constraints of the communication quality of service of primary users,energy harvested threshold,and transmission power threshold,etc.,a scheme to maximize the throughput of the secondary system is proposed.The simulation results show that the proposed joint allocation algorithm has good performance regardless of whether the UAV relay is in hovering state or mobile state.The throughput of the secondary system can be maximized.Finally,a non orthogonal multiple access network(NOMA)model based on UAV relay is established for the two-tier multi-user network in 5G scenario by jointly optimize the transmission power,power splitting ratio and subcarrier allocation.With the goal of maximizing the achievable rate of the system,nearby user power control and its subcarrier allocation and remote user power control schemes are designed.The convex optimization of the problem is completed respectively.The simulation results prove the convergence and effectiveness of the proposed algorithm.The system rate is maximized by the algorithm.