Nowadays, efficient spectrum usage is one of the most important design principles to take into account in wireless communications due to the exponential growth of mobile devices. In that sense, solutions such as non-orthogonal multiple access (NOMA) and cognitive radio (CR), investigated separately, have been proposed to overcome the spectrum scarcity issue. However, it is important to quantify the benefits of the link of both technologies to improve spectrum utilization. In this work, a novel mathematical model of teletraffic for resource allocation using power-domain NOMA (PD-NOMA) in a cognitive radio (CR) environment, specifically in the interweave spectrum sharing scheme, calculating the birth-death process by teletraffic analysis, is developed. This new methodology involves a mathematical model where users can be born or die as primary or secondary users and are represented by a two-dimensional Markovian process. Mathematical results are validated through simulations considering three different scenarios. In these scenarios, a comparison between PD-NOMA and orthogonal multiple access (OMA) schemes is presented considering the blocking probability and the average number of users. The proposed mathematical model shows convergence to the performed simulations. The outcomes indicate that PD-NOMA increases the blocking probability, however, if this parameter is less than 0.03, the average number of active users is at least 90% higher compared to the OMA case.

如今，由于移动设备的指数级增长，有效使用频谱已成为无线通信中要考虑的最重要的设计原则之一。从这个意义上讲，已经提出了分别研究的非正交多路访问（NOMA）和认知无线电（CR）之类的解决方案来克服频谱稀缺问题。但是，重要的是量化两种技术的链接所带来的好处，以提高频谱利用率。在这项工作中，一种新型的交通运输数学模型，用于在认知无线电（CR）环境中，特别是在交织频谱共享方案中，使用功率域NOMA（PD-NOMA）进行资源分配，通过交通运输分析来计算出生-死亡过程，被开发。这种新方法涉及一个数学模型，其中用户可以出生或死亡为主要或次要用户，并由二维马尔可夫过程表示。通过考虑三种不同情况的仿真对数学结果进行了验证。在这些情况下，考虑了阻塞概率和平均用户数，提出了PD-NOMA与正交多路访问（OMA）方案之间的比较。所提出的数学模型显示出对所进行的仿真的收敛性。结果表明，PD-NOMA增加了阻止概率，但是，如果此参数小于0.03，则与OMA情况相比，活动用户的平均数量至少高90％。通过考虑三种不同情况的仿真对数学结果进行了验证。在这些情况下，考虑了阻塞概率和平均用户数，提出了PD-NOMA与正交多路访问（OMA）方案之间的比较。所提出的数学模型显示出对所进行的仿真的收敛性。结果表明，PD-NOMA增加了阻止概率，但是，如果此参数小于0.03，则与OMA情况相比，活动用户的平均数量至少高90％。通过考虑三种不同情况的仿真对数学结果进行了验证。在这些情况下，考虑了阻塞概率和平均用户数，提出了PD-NOMA与正交多路访问（OMA）方案之间的比较。所提出的数学模型显示出对所进行的仿真的收敛性。结果表明，PD-NOMA增加了阻止概率，但是，如果此参数小于0.03，则与OMA情况相比，活动用户的平均数量至少高90％。