Study Of The Non-orthogonal Multiple Access In 5G Systems

Non-orthogonal Multiple Access(NOMA)is one of the promising techniques determined to be deployed in five-generation mobile communication systems,which aims at improving the cell-edge users' experience together with highlighting the overall throughput of the system.This thesis is started with the introduction and analysis of the common power-domain NOMA.In the second chapter,three different power allocation methods are proposed for specific scenarios,along with the matching algorithm for deploying users in some sort of subbands.Different from other ways,the probability theory is chosen to depict the dominance over conventional Orthogonal Multiple Access(OMA).With the aim of guaranteeing the given user's quality of service,whilst improving the spectrum efficiency of the system together with the improvement of every single user's throughput and reception reliability as large as possible,NOMA is combined with the AF-relay and cognitive radio system in chapter four.The selection of the relay node and power allocation in the systems are settled there.Coming with the energy-efficiency problem,in chapter five,NOMA is used in the wireless powered communication networks(WPCN)to effectively solve the far-near effects and to enlarge the serving time of the network nodes with information and energy transmitting adaptively.In this thesis,the performance analysis is launched around typical aspects,including capacity analysis,outage analysis and energy-efficiency analysis.In every chapter,the simulation results are provided to check the accuracy of the corresponding derived and approximation results.