In this article, we investigate the integration of NOMA into cooperative relaying. We first introduce several fundamental cooperative NOMA network structures, and then classify them into two categories: user relaying and dedicated relaying. After that, we discuss the combination of cooperative NOMA with various advanced transmission technologies, such as full-duplex, cognitive radio, energy harvesting and multiple-input multiple-output. Following this, we focus on system evaluation and resource allocation of cooperative NOMA. Finally, major challenges and open issues are highlighted.

中文翻译：

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合作 NOMA：最先进的技术、关键技术和开放的挑战


在本文中，我们研究了将 NOMA 集成到协作中继中。我们首先介绍几种基本的协作NOMA网络结构，然后将它们分为两类：用户中继和专用中继。之后，我们讨论了协作NOMA与各种先进传输技术的结合，例如全双工、认知无线电、能量收集和多输入多输出。接下来，我们重点关注合作NOMA的系统评估和资源分配。最后，强调了主要挑战和悬而未决的问题。