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Abstract: near-field technology is increasingly recognized due to its transformative potential in communication systems, establishing it as a critical enabler for sixth-generation (6G) telecommunication development. This paper presents a comprehensive survey of recent advancements in near-field technology research. First, we explore the near-field propagation fundamentals by detailing definitions, transmission characteristics, and performance analysis. Next, we investigate various near-field channel models—deterministic, stochastic, and electromagnetic information theory based models, and review the latest progress in near-field channel testing, highlighting practical performance and limitations. With evolving channel models, traditional mechanisms such as channel estimation, beamtraining, and codebook design require redesign and optimization to align with near-field propagation characteristics. We then introduce innovative beam designs enabled by near-field technologies, focusing on non-diffractive beams (such as Bessel and Airy) and orbital angular momentum (OAM) beams, addressing both hardware architectures and signal processing frameworks, showcasing their revolutionary potential in near-field communication systems. Additionally, we highlight progress in both engineering and standardization, covering the primary 6G spectrum allocation, enabling technologies for near-field propagation, and network deployment strategies. Finally, we conclude by identifying promising future research directions for near-field technology development that could significantly impact system design. This comprehensive review provides a detailed understanding of the current state and potential of near-field technologies.

近场通信：基础特性、关键技术与工程化应用

赵亚军^1,2，戴凌龙³，张建华⁴，季然⁵，菅梦楠^1,2，薛皓^6,7，禹宏康^1,2，孙韵淇^1,2，陆宇³，吴梓栋³，徐卓³，李金珂³，缪海烊⁴，袁志强⁴，唐盼⁴，沈嘉宇⁵，宫铁瑞⁵，刘海霞^6,7，韩家奇^6,7，冯强^6,7，陈智⁸，李玲香⁸，杨刚⁸，曾勇^9,10，潘存华⁹，刘望⁹，支康达¹¹，胡伟东¹²，刘元玮¹³，慕熹东¹⁴，严超¹⁵，Mérouane DEBBAH¹⁶，黄崇文⁵，李龙^6,7，张平^4
1移动网络和移动多媒体技术国家重点实验室，中国深圳市，518055
²中兴通讯股份有限公司，中国北京市，100192
³清华大学电子工程系，中国北京市，100084
⁴北京邮电大学网络与交换技术国家重点实验室，中国北京市，100876
⁵浙江大学信息科学与电子工程学院，中国杭州市，310007
⁶西安电子科技大学电子工程学院超高速电路设计与电磁兼容教育部重点实验室，中国西安市，710071
⁷西安电子科技大学信息感知技术协同创新中心，中国西安市，710071
⁸电子科技大学通信抗干扰全国重点实验室，中国成都市，611731
⁹东南大学移动通信全国重点实验室，中国南京市，210096
¹⁰紫金山实验室，中国南京市，211111
¹¹柏林工业大学电气工程与计算机科学学院，德国柏林市，10623
¹²北京理工大学集成电路与电子学院，中国北京市，100081
¹³香港大学电机电子工程系，中国香港特别行政区
¹⁴英国贝尔法斯特女王大学电子、电气工程和计算机科学学院无线创新中心，英国贝尔法斯特，BT3 9DT¹⁵南洋理工大学电气与电子工程学院，新加坡，639798
¹⁶哈利法科学技术大学KU 6G研究中心，阿拉伯联合酋长国阿布扎比
摘要：近场技术因其对通信系统的变革性潜力而日益受到认可，成为推动第六代（6G）系统发展的关键技术。本文全面综述了近场技术研究的最新进展。首先，深入探讨了近场传播的基本原理，详细阐述了其定义、传输特性和性能分析。接着，研究了各种近场信道模型，包括确定性模型、随机性模型和基于电磁信息理论的模型，并回顾了近场信道测试的最新进展，重点介绍了实际性能及其局限性。随着信道模型的不断发展，传统的信道估计、波束训练、码本设计等机制需要重新设计和优化，以适应近场传播特性。随后，介绍了近场技术所支持的新型波束设计，重点讨论了非衍射波束（如贝塞尔波束和艾里波束）和轨道角动量（OAM）波束，同时涉及硬件架构和信号处理框架，展示了它们在近场通信系统中的革命性潜力。此外，强调了工程和标准化方面的进展，涵盖了6G的主要频谱分配、支持近场传播的关键技术以及网络部署策略。最后，总结了近场技术发展的未来研究方向，这些方向有望对系统设计产生重大影响。这篇综述文章提供了对近场技术当前状态和未来潜力的深入理解。

关键词：6G；近场技术；信道模型；码本；非衍射波束；轨道角动量；工程与标准化

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