Clock and Carrier Synchronization Using Optical Frequency Combs in Radio Access Networks

The operation of wireless communication systems, particularly in next-generation networks like 6G, has become increasingly complex, driving a growing demand for precise synchronization, especially with the introduction of technologies such as massive MIMO, ultra-dense cell deployments and Integrated Sensing and Communications (ISAC). This paper proposes a novel method for achieving clock and carrier synchronization using optical frequency combs. By leveraging Wavelength Division Multiplexing (WDM) to combine clock and data signals, and transmitting them over a Single-Mode Fiber (SMF), the system ensures precise synchronization across extensive distances.
A 2.5 GHz spaced optical frequency comb is combined with optical data streams, and transmitted through the fiber network. Upon reception, the signals are demultiplexed and converted into electrical form, with the carrier frequencies successfully synchronized at 2.5 GHz, 5 GHz, and 7.5 GHz. The paper presents simulation and experimental results to validate the proposed methodology, demonstrating its feasibility for highprecision synchronization in wireless communications. The results highlight the potential of optical frequency combs to enhance the performance of future communication networks, supporting high-speed data transmission with minimal latency and improved reliability.