Research On Resource Allocation Algorithm For Cooperative Multi-Carrier NOMA System

Since the commercialization of 5G wireless communication networks,the volume of communication services and data in 5G networks has exploded,and the number of base station deployments has increased dramatically.The surge in the number of base stations will not only increase the operating costs of operators,but also increase the carbon emissions of wireless communication systems.Balancing the contradiction between the operation and construction cost of wireless communication system and user expense,as well as improving the total energy efficiency of wireless communication system to achieve "green communication" are two issues of theoretical research and practical application in the field of wireless communication.For the cooperative multi-carrier nonorthogonal multiple access(MC-NOMA)system,the downlink resource allocation algorithm is studied to improve the benefits of base stations and users,as well as the total system energy efficiency.The main work is as follows.For the cooperative MC-NOMA system,the joint strong-weak user pairing and subchannel assignment algorithm and the optimal user power allocation algorithm in subchannel which using Difference of Convex(DC)programing iterative solution are proposed based on stackelberg game theory with the objective of maximizing the base station and users benefits.The simulation results show that under high signalto-noise ratio conditions,compared with the joint user pairing and subchannel assignment algorithm and the worst-case user first subchannel allocation algorithm,the joint strong weak user pairing and subchannel assignment algorithm has increased user benefits by 2.82% and 12.66%.Compared with the power allocation algorithm based on stackelberg game,the optimal user power allocation algorithm has increased user benefits and base station benefits by 12.70% and 22.37%,respectively.Compared with the joint strong weak user pairing and subchannel assignment algorithm and the stackelberg game based power allocation algorithm,the sum rate of the system using both the joint strong weak user pairing and subchannel assignment algorithm and the optimal user power allocation algorithm has increased by 16.59%.In order to improve the energy efficiency of cooperative MC-NOMA system,simultaneous wireless information and power transfer(SWIPT)technology is introduced,and close up users have the function of simultaneous energy and information transmission.The problem of maximizing the energy efficiency of MCNOMA system based on SWIPT technology is studied.The problem is transformed into three sub-problems of intra-subchannel user power allocation,inter-subchannel power allocation,and relay power partitioning for solving,and the optimal power allocation scheme is derived.The simulation results show that under high signal-tonoise ratio,the resource allocation strategy proposed in this paper improves the total energy efficiency of the downlink cooperative MC-NOMA system by 17.73%compared to the average allocation power and fractional order power allocation algorithms.