As the core technology of mobile communication system, multiple access technology directly determines the performance and capacity of the system. However, with the rapid growth of the number of mobile communication system users and the high rate service demand, these orthogonal multiple access technologies are limited by the spectrum efficiency and access capacity, so it is difficult to meet the future mobile communication demand. Therefore, for the fifth generation mobile communication system (5G), the research of non-orthogonal multiple access (NOMA) technology to effectively improve the system capacity has been widely concerned. The purpose of this paper is to analyze the influence of interference and power distribution on system performance simulation based on the simulation results of two most representative NOMA technologies, sparse code division multiple access (SCMA) and NOMA. This paper firstly briefly analyzes the SCMA system model and key technologies and, on this basis, introduces the SCMA system simulation platform, including basic platform parameters and platform simulation flow chart. Furthermore, the influence of adaptive modulation coding on the performance improvement of SCMA system is analyzed by simulation. Then, based on the NOMA system model, this paper carried out the research on fairness among NOMA users. Based on Lagrange multiplier method, this paper simulates fairness under the restriction of power allocation optimization algorithm, the number of users in different area, different radius and different transmission power, the village of village fair index, the change of the frequency spectrum efficiency and energy efficiency curve, the throughput rate between 0.8 and 1.4 changes, and the conclusion that has a guiding significance for NOMA system design.

中文翻译：

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5G移动通信网络非正交多址技术系统级性能仿真分析

多址技术作为移动通信系统的核心技术，直接决定了系统的性能和容量。然而，随着移动通信系统用户数量的快速增长和高速率业务需求，这些正交多址技术受到频谱效率和接入容量的限制，难以满足未来的移动通信需求。因此，针对第五代移动通信系统（5G），研究非正交多址接入（NOMA）技术以有效提高系统容量受到广泛关注。本文的目的是基于两种最具代表性的 NOMA 技术的仿真结果，分析干扰和功率分布对系统性能仿真的影响，稀疏码分多址 (SCMA) 和 NOMA。本文首先简要分析了SCMA系统模型和关键技术，并在此基础上介绍了SCMA系统仿真平台，包括基本平台参数和平台仿真流程图。此外，通过仿真分析了自适应调制编码对SCMA系统性能提升的影响。然后，基于NOMA系统模型，本文对NOMA用户之间的公平性进行了研究。基于拉格朗日乘子法，模拟了功率分配优化算法、不同区域、不同半径、不同发射功率的用户数量、村村落公平指数、频谱效率和能量变化等限制下的公平性。效率曲线，