Research On Resource Allocation About Non-linear Eh Model In Multi-relays Cooperative System

On the research of wireless communication networks,wireless relay technology has become a key technology for effectively expanding wireless communication coverage and achieving cooperative diversity.However,this technology is greatly limited due to limited relay capacity and service life.Considering that radio frequency(RF)signals have the characteristics of carrying information and energy at the same time,many studies have been proposed to continue the use of the Simultaneous Wireless Information and Power Transfer(SWIPT)technology as energy constrained.An effective solution to the aviation problem.Among the numerous methods for resource allocation of multi-relay cooperative systems using SWIPT technology,the energy harvesting(EH)model is generally considered.However,according to existing studies,the input-output characteristics of the actual EH circuit are non-linear.If the linear EH model is used to design the resource allocation algorithm,it will result in a certain loss of the total harvest energy,making the resource allocation effect unable to reach the maximum value.good.Therefore,in this paper,for the single-multi-relay cooperative communication system resource allocation problem,two different solutions for the relay EH circuit based on the nonlinear model are proposed.The specific research work is as follows:In order to solve the problem of optimal allocation of single relay resources based on nonlinear EH model,this paper proposes a joint resource allocation algorithm based on relay transmit power and power splitting factor.First,we consider the Amplify-and-Forward(AF)and Decode-and-Forward(DF)information forwarding mechanisms for the allocation of single energy-splitting AF/DF relay resources based on the nonlinear EH model.The problems are modeled separately.Finally,these two problems are transformed into convex problems.The joint optimal solution for the relay transmit power and the power splitting factor can be obtained through the convex optimization algorithm.The main conclusions are as follows:(1)In the actual relay cooperation system application scenario,the nonlinear EH model is superior to the linear EH model for the goal of maximizing the AF/DF system rate,thus validating the necessity of applying the nonlinear EH model.(2)Based on the analysis ofAF/DF relay system resource allocation results based on nonlinear EH model,the maximum system rate obtained by applying the joint optimized resource allocation algorithm is considered only when the fixed energy fraction coefficient is used.The overall optimization effect of the single optimization resource allocation algorithm is better.In order to solve the problem of optimal allocation of multi-resource resources based on nonlinear EH model,this paper proposes a joint resource optimization algorithm based on relay selection factor,relay transmission power and power splitting factor.First,the resource allocation problem of multiple 2-hop relay cooperative communication systems based on nonlinear EH model is modeled.Then,by analyzing the optimization model,the objective problem is a nonlinear integer programming problem.The complexity of solving the problem through the poor search method or the convex optimization algorithm is too high.Therefore,this paper proposes the use of genetic algorithm as a multi-relay selection strategy,and combines the relay transmit power and power splitting factor to optimize the power allocation algorithm to solve the optimal resource allocation problem.By giving detailed algorithm steps and related parameter settings,and analyzing the simulation results,we conclude that the same considerations should be used in conjunction with the relay transmit power and power splitting factor to optimize the power allocation algorithm,and apply the full participation in the relay selection strategy or select the best single.Relay selection strategy These two multi-relay selection strategies apply genetic algorithm as multi-relay selection strategy to solve the problem of multi-resource resource optimization allocation based on nonlinear EH model.The results show that the three proposed joint optimization The algorithm obtains greater energy efficiency while sacrificing the maximum transmission rate of a small part of the system.At this time,the system performance also improves significantly,thus verifying the effectiveness of the algorithm.