Research On Resource Allocation Strategy Of Interfered SWIPT Relay System

With the arrival of the 5G era and the expansion of the wireless network,the number of nodes in the network will increase dramatically.Traditional network nodes use batteries to supply energy,which means that network nodes have a limited life cycle.Faced with more and more nodes,replacing batteries for them obviously will waste a lot of manpower and resources.However,the emergence and development of Simultaneous Wireless Information and Power Transfer(SWIPT)technology has provided new ideas for solving this problem.SWEPT technology enables nodes in a wireless network to harvest energy through RF signals and use the harvested energy to decode information.This technology avoids the drawbacks of frequent battery replacement and can greatly extend the life of nodes in the network.Therefore,the application of SWEPT technology in wireless networks has attracted much attention.This paper mainly studies the SWIPT relay resource allocation scheme under interference.According to the different interference situations,this paper mainly includes the following three parts.1.For periodic strong interference signals,when the relay knows the interference information,the Interference Energy Redistribution(IER)scheme is proposed.When strong interference occurs,the relay switches to the energy harvesting mode to harvest the energy of interference.The harvested interference energy is used for information forwarding after the end.Through mathematical derivation,the feasibility of the IER scheme to improve the performance of time switching(TS)relay and power splitting(PS)relay system is proved.The function relationships between the speed and time switching rate and the power splitting rate of the two relay systems are found.The optimal values of the system rates can be found by the extreme value method.Through numerical simulation,it is found that the IER scheme can effectively improve the average speed of the relay system.2.For the periodic strong interference signals,when the relay can not obtain the interference information,the modified Interference Energy Redistribution(MIER)scheme is proposed based on the IER scheme.From a statistical point of view,the scheme can calculate the optimal number of energy splits N*based on the statistical information of the interference.Based on MIER,two TS relay optimization targets are proposed,which correspond to the static time switching rate optimal solution and the adaptive time switching rate optimal solution.Both methods have a significant increase in system speed,and the latter performs better.However,the latter increases device complexity.3.For the general interference signals,the h2 method is proposed for resource allocation.The method establishes a resource allocation coordinate system,and divides the energy-harvesting and decode-forwarding area by adjusting the resource allocation line h2.Through derivation,the relationship between the non-disruption probability of the system and h2 is found.Aiming at maximizing the non-interruption probability,the golden section method is used to solve the optimal value.After numerical simulation,the h2 method can effectively improve the non-interruption probability of the system.