Near-Field Communications for 6G: Fundamentals, Challenges, Potentials, and Future Directions
Near-Field Communications for 6G: Fundamentals, Challenges, Potentials, and Future Directions
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6G 近场通信：基础知识、挑战、潜力和未来方向
DOI：
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
L. Dai
中科院分区：
文献类型：
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作者：
Mingyao Cui;Zi;Yu Lu;Xiuhong Wei;L. Dai
超大型天线阵列（ELAA）是第六代移动的网络（6 G）的几种关键候选技术的共同特征，例如超大规模多输入多输出（UM-MIMO）、无小区大规模MIMO、可重构智能表面（RIS）和太赫兹通信。由于ELAA的天线数量非常大，因此电磁辐射场需要通过近场球面波建模，这与5G大规模MIMO的传统平面波辐射模型相反。因此，近场通信将成为6 G无线网络中必不可少的部分。在这篇文章中，我们系统地研究了新兴的近场通信技术。首先，我们介绍了近场通信的基本原理和在典型通信场景中确定近场距离的度量。然后，我们调查了最近的研究，具体到近场通信分为两类，即，技术解决的挑战和那些利用近场区域的潜力。讨论了它们的原理、最新进展和优缺点。更重要的是，指出了近场通信的几个开放性问题和未来的研究方向。我们相信，这篇文章将为6 G近场通信这一重要研究课题带来更多创新。
Extremely large antenna array (ELAA) is a common feature of several key candidate technologies for sixth-generation mobile networks (6G), such as ultra-massive multiple-input-multiple-output (UM-MIMO), cell-free massive MIMO, reconfigurable intelligent surface (RIS), and terahertz communications. Since the number of antennas is very large for ELAA, the electromagnetic radiation field needs to be modeled by near-field spherical waves, which is opposed to the conventional planar-wave-based radiation model of 5G massive MIMO. As a result, near-field communications will become essential in 6G wireless networks. In this article, we systematically investigate the emerging near-field communication techniques. Firstly, we present the fundamentals of near-field communications and the metric to determine the near-field ranges in typical communication scenarios. Then, we investigate recent studies specific to near-field communications by classifying them into two categories, i.e., techniques addressing the challenges and those exploiting the potentials in near-field regions. Their principles, recent progress, pros and cons are discussed. More importantly, several open problems and future research directions for near-field communications are pointed out. We believe that this article would inspire more innovations for this important research topic of near-field communications for 6G.
影响因子：
9.3
作者：
Saad, Walid;Bennis, Mehdi;Chen, Mingzhe
通讯作者：
Chen, Mingzhe