Multifunctional fronthaul architecture enabled by electro-optic comb cloning

作者：Jingjing Lin, Chenbo Zhang, Weihan Liang, Yi Zou, Yixiao Zhu, Weisheng Hu, Zhangyuan Chen, Weiwei Hu, Xiaopeng Xie · 发表于：Photonics Research · 年份：2025 · DOI：10.1364/prj.552048 · 被引用次数：4 · 研究领域：Semiconductor Lasers and Optical Devices、Optical Network Technologies、Advanced Fiber Laser Technologies

Beyond providing user access to the core network, the radio access network (RAN) is expected to support precise positioning and sensing for emerging applications such as virtual reality (VR) and drone fleets. To achieve this, fronthaul—the link connecting the central units/distributed units (CUs/DUs) to wireless remote units (RUs) in centralized RAN—must realize both high-capacity transmission and low-timing-jitter clock synchronization between RUs. However, existing solutions fall short of supporting these functions within one simple, cost-effective network. In this work, we propose a solution that simultaneously achieves picosecond-level timing jitter clock distribution and Tb/s data transmission with simplified DSP, using an electro-optic (EO) comb cloning technique to enable multifunctionality in fronthaul systems. Through the delivery of pilot comb lines, a 1 ps (integrated from 1 Hz to 40 MHz) low-timing-jitter 100 MHz clock is distributed by the beating of adjacent pilot comb lines and subsequent frequency dividing, realizing frequency synchronization between the CUs/DUs and RUs. Moreover, the delivery of pilot comb lines also facilitates self-homodyne structures through EO comb cloning, and supports wavelength division multiplexing (WDM) transmission with a line capacity of 2.88 Tb/s and a net capacity of 2.5 Tb/s. Thanks to the clock-synchronized and self-homodyne structure, DSP is streamlined, with digital timing recovery, carrier phase estimation, and frequency off...