下一代光接入网中物理层关键技术研究进展

5G和数据密集型应用的兴起对下一代光接入网的容量提出了新的挑战.作为最成熟的宽带光纤接入技术，无源光网络（passive optical network，PON）受到了广泛关注.为了在满足功率预算的前提下实现更高的传输速率，提升物理层性能的关键技术一直是该领域的研究热点，同时尽可能地降低系统成本对PON的大规模部署有着重大意义.该文梳理并总结了光接入网中物理层关键技术的研究进展.介绍了PON标准的演进和现状，分析了下一代PON面临的挑战和成因，重点阐述了数字均衡技术、高阶调制格式、光放大、前向纠错、非线性串扰实验分析以及低成本相干检测等关键技术及其研究进展，并综述了当前相关工作的研究成果.

Progress in Key Technologies of Physical Layer in Next Generation Optical Access Networks

The rapid growth of 5G and data-intensive applications poses new challenges to the capacity of next-generation optical access networks. As the most mature broadband fiber access technology, passive optical networks (PON) has drawn widespread attention. In order to achieve a higher transmission rate under the premise of meeting the power budget, the key technology to improve the performance of the physical layer has always been a research hotspot in this field. Meanwhile, it is of great significance to reduce the system cost as much as possible for the large-scale deployment of PON. In this paper, we describe and summarize the research progress of key physical layer technologies in optical access network. We introduce the evolution and current status of the PON standards, analyze the challenges and causes in the next-generation PON, and focus on the key technologies such as digital equalization technology, high-order modulation formats, optical amplification, forward error correction, experimental analysis of nonlinear crosstalk, and low-cost coherent detection and their research progress. We also review the current research achievements of relevant works.