Research On Wireless Resource Allocation Mechanism In Multi-Carrier Non-orthogonal Multiple Access System

The continuous development of human society has caused future communication networks to put forward higher requirements for communication performance indicators such as system throughput,user rate,and number of user accesses.Therefore,researchers have carried out extensive research on future communication technologies.Among them,Non-Orthogonal Multiple Access(NOMA),a new type of multiple access technology,has attracted much attention due to its excellent theoretical communication performance.Compared with Orthogonal Multiple Access(OMA),NOMA can significantly improve the system spectrum utilization by multiplexing multiple users on each carrier,and accordingly,it can lead to mutual interference among users,and if the power allocation scheme among users is not appropriate,the actual system performance may not reach the system design goal.This thesis analyzes different design goals and user requirements,and study the NOMA resource allocation method in terms of power control,user pairing and channel allocation.The main work includes the following two aspects.1.A power allocation scheme to improve the fairness of system users in a multi-carrier NOMA system is proposed.For the NOMA system,according to the system channel gain,it is divided into central user,edge subweak user and edge user.The channel gain difference between edge user and central user is huge,the channel gain of edge user is lower,if it allocates higher power will result in performance degradation such as the energy efficiency of the entire system,and at the same time,the rate improvement room for edge users is relatively small.Therefore,by appropriately reducing the power of the central user and allocating it to the edge subweak users,the fairness of the system users can be improved.For the entire NOMA system,an appropriate inter-user power allocation scheme is proposed in order to improve the user fairness of the system.Finally,the proposed power allocation scheme is verified by simulation,and it is found that the proposed scheme can appropriately improve the user fairness of the system and achieve the scheme design goal.2.This thesis proposes a NOMA power allocation scheme that optimizes Quality of Service(Qo S)performance.For most NOMA systems,Qo S is not a important constraint,With the increase of Qo S,the energy efficiency of the system will decrease with the gradual increase of Qo S,until the system cannot work properly.However,certain realistic requirements require researchers to consider the system energy efficiency under higher Qo S constraints.Therefore,this thesis designs a NOMA power allocation scheme that optimizes Qo S performance,and uses game theory to jointly allocate user power and carriers.The simulation verification results show that compared with the comparison scheme,the proposed scheme can improve a certain energy efficiency under higher Qo S constraints and achieve the design goal of the scheme.