Research On Radio Resource Allocation For Non-orthogonal Multiple Access

Fifth-generation(5G)mobile communications technology has very high requirements on spectrum utilization efficiency and time delay.In order to meet these requirements,non-multiple access multiple access technology has been put forward.Nowadays the most popular ones are Non-Orthogonal Multiple Access(NOMA)proposed by Japan's NTT DOCOMO and Sparse Code Multiple Access(SCMA)proposed by Huawei.Both of these multiple access technologies can improve the system's spectrum efficiency significantly by utilizing multi-user multiplexing of spectrum resources.In addition,with the advent of 5G technology,people are increasingly eager to get more wireless resources.However,people are increasingly eager to get more wireless resources,so limited spectrum resources are more invaluable.Hence,how to use these valuable spectrum resources effectively will greatly affect the system throughput.This thesis focuses on the research of two non orthogonal multiple access technologies called SCMA and NOMA and mainly studies on the wireless resource allocation of SCMA and NOMA.Several resource allocation algorithms are proposed by this paper.The main works and innovations of this thesis are as follows:1.To maximize the throughput of the SCMA system,this paper presents an algorithm of SCMA resource allocation based on layer allocation of ant colony algorithm and water filling power algorithm to improve the throughput of SCMA system,simulation shows that the proposed layer allocation of ant colony algorithm and water filling power algorithm can all significantly improve throughput of the SCMA system compared to the traditional ant colony algorithm layer allocation of equal power allocation and random layer allocation of water filling power algorithm.2.Given the problem of insufficient battery capacity in SCMA system receiver,in order to improve data rate and energy harvesting rate,an iterative resource allocation algorithms is proposed in this paper.Simulation shows the algorithm proposed by this paper not only can improve data rate and energy harvesting rate but also can achieve atradeoff between data rate and energy harvesting rate compared to the random layer and power allocation.3.For the downlink NOMA systems,in order to reduce the complexity of the proportional fairness scheduler,this paper proposes a low complexity waterfilling power and proportional fairness(Waterfilling-PF)scheduling algorithm to the downlink single-user multiple-input multiple-output case.Simulation shows the low complexity Waterfilling-PF scheduling algorithm not only does not entail any penalty in performance but also can improve the user fairness by increasing the rate of the cell-edge user significantly.