In this article, we review the key concepts and the progress in the design of physical-layer aspects of in-band full-duplex (IBFD) communications. One of the fundamental challenges in realizing IBFD is self-interference that can be up to 100 dB stronger than signals of interest. Thus, we start by reviewing state-of-the-art research in self-interference cancellation, addressing both model-based and emerging machine learning-based methods. Then, we turn our attention to new wireless systems with many degrees of freedom for which the traditional IBFD designs do not gracefully scale and, hence, require many innovations to enable IBFD. We provide an extensive review of basic concepts and state of the art in massive multiple-input–multiple-output IBFD. Then, we consider the mmWave band IBFD and review advanced physical-layer architectures. The above review provides the proper context to discuss IBFD innovations and new challenges for sixth-generation networks and beyond, where wireless networks are envisioned to be multifunctional, combining communications with functions such as sensing, cognitive radios, physical-layer security, and wireless power transfer. We conclude this article with a status update on the adoption of IBFD in communication standards.

中文翻译：

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带内全双工：物理层


在本文中，我们回顾了带内全双工 (IBFD) 通信物理层方面的关键概念和设计进展。实现 IBFD 的基本挑战之一是自干扰，其强度可能比感兴趣的信号强 100 dB。因此，我们首先回顾自干扰消除的最先进研究，解决基于模型和新兴的基于机器学习的方法。然后，我们将注意力转向具有多种自由度的新无线系统，传统的 IBFD 设计无法很好地扩展这些系统，因此需要许多创新来实现 IBFD。我们对大规模多输入多输出 IBFD 的基本概念和最新技术进行了广泛的回顾。然后，我们考虑毫米波频段 IBFD 并回顾先进的物理层架构。上述评论提供了讨论 IBFD 创新和第六代网络及更高版本的新挑战的适当背景，其中无线网络被设想为多功能的，将通信与传感、认知无线电、物理层安全和无线电源等功能相结合转移。我们以通信标准中采用 IBFD 的最新状态来结束本文。