TCEP-Based Synchronization for Practical Communication Network

Precise time synchronization is a fundamental challenge in distributed quantum systems, with direct implications for secure communication, sensing, and next-generation network technologies. In this study, we present a Field Programmable Gate Array (FPGA)-based implementation of a Time-Correlated Entangled Photons (TCEP) source-based synchronization system, achieving <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sub-nanosecond</i> accuracy with timing jitter consistently below 200 ps for a distance up to 20 km. The system leverages the strong temporal correlations inherent in entangled photon pairs to compute synchronization offsets between spatially separated nodes. The design features a modular architecture with optimized kernels for temporal correlation, data aggregation, and normalization, enabling efficient resource utilization and high-throughput performance. Experimental validation demonstrates the FPGA's ability to process photon timestamp data and compute cross-correlation functions significantly faster than traditional CPU-based approaches, achieving execution times in the millisecond range even for large datasets. Our FPGA implementation achieved a consistent <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim$</tex-math></inline-formula> 800 times speedup over CPU, with performance largely unaffected by channel length. Resource utilization analysis highlights the scalability of the design, with the fully integrated system operating at a clock frequency of 397.5 MHz while maintaining efficient use of logic elements, registers, and memory blocks. This hardware-efficient approach provides the timing backbone for next-generation technologies, facilitating advancements in ultra-reliable low-latency communication, distributed quantum computing, quantum-enhanced sensing, navigation, and lays a foundation for forthcoming 6G networks and the quantum internet.