Robust aperiodic synchronous scheme for satellite-to-ground quantum key distribution

Area of Science:

• Quantum Information Science
• Optical Communications
• Satellite Technology

Background:

• Time synchronization is critical for quantum key distribution (QKD) across various platforms, including satellite-to-ground links.
• Existing satellite QKD systems often rely on complex two-stage synchronization using Global Navigation Satellite Systems (GNSS) and light synchronization to counter Doppler effects and link instability.

Purpose of the Study:

• To propose and validate a novel, simplified aperiodic synchronization scheme for satellite-to-ground quantum key distribution.
• To reduce system complexity and cost by minimizing reliance on GNSS hardware.

Main Methods:

• Developed a new synchronization scheme encoding time information into pseudo-random laser pulse positions.
• Conducted experimental demonstrations to validate the scheme's feasibility and robustness under challenging conditions.

Main Results:

• Achieved high-precision time synchronization in the range of 208-222 picoseconds.
• Demonstrated robust performance even with up to 90% loss of optical signals.
• Provided analysis of the Doppler effect specific to satellite-to-ground communication.

Conclusions:

• The proposed aperiodic synchronization scheme offers a simplified and cost-effective solution for high-precision time synchronization in satellite QKD.
• This robust method is suitable for future satellite-based quantum information applications, enhancing their practicality and reliability.