This study investigates the performance of a cooperative non-orthogonal multiple access cognitive network with imperfect successive interference cancellation under Rayleigh fading conditions. Specifically, the authors consider an underlay cognitive network that consists of a primary transmitter–receiver pair and a secondary system where a source node communicates with two destinations nodes directly and indirectly through a relay node selected from a set of decode-and-forward relays. A partial relay selection scheme is used to determine the best relay. The authors present an analytical framework, with closed-form analytical expressions for the outage probabilities at the two destinations as well the primary destination. Moreover, to simplify the analysis and to provide further insights into the impact of key system parameters, asymptotic studies of the outage probabilities were carried out. To this end, the authors focus on two cases: (i) the maximum allowable transmit power of the secondary network grows sufficiently large and (ii) the interference power approaches infinity. Finally, Monte Carlo simulations are provided in an effort to assess the accuracy of the proposed mathematical framework.

中文翻译：

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具有不完善的连续干扰消除的底层频谱共享非正交多址网络

这项研究调查了在瑞利衰落条件下具有不完善的连续干扰消除的协作式非正交多址认知网络的性能。具体来说，作者考虑了一个底层认知网络，它由一个主要的发送器-接收器对和一个辅助系统组成，在该系统中，源节点通过从一组解码转发中继中选择的中继节点直接或间接地与两个目标节点进行通信。使用部分中继选择方案来确定最佳中继。作者提出了一个分析框架，其中包含针对两个目的地以及主要目的地的中断概率的闭式分析表达式。此外，为简化分析并进一步了解关键系统参数的影响，进行了停机概率的渐近研究。为此，作者集中于两种情况：（i）次级网络的最大允许发射功率变得足够大，并且（ii）干扰功率接近无穷大。最后，提供了蒙特卡洛模拟，以评估所提出的数学框架的准确性。