Semi-Empirical Satellite-to-Ground Quantum Key Distribution Model for Realistic Receivers

Abstract

Satellite-based link analysis is valuable for efficient and secure quantum communication, despite seasonal limits and restrictions on transmission times. A semi-empirical quantum key distribution model for satellite-based systems was proposed that simplifies simulations of communication links. Unlike other theoretical models, our approach was based on the experimentally-determined atmospheric extinction coefficient typical for mid-latitude ground stations. The parameter was measured for both clear and foggy conditions, and it was validated using published experimental data from the Micius satellite. Using this model, we simulated secure QKD between the Micius satellite and ground stations with 300 mm and 600 mm aperture telescopes.

Vector—towards quantum key distribution with small satellites

“…The corresponding diffraction loss is 26.0 dB more, 65.0 dB and 72.4 dB. Attenuation in atmosphere depends on weather conditions: at a wavelength of 850 nm, 1 4 • κ lies in the range from 0.23 for clear weather to 0.41 for foggy weather [41]. The loss varies from 0.9 dB at the best weather conditions at zenith to 4.8 dB at the worst weather conditions at an elevation of 20°: see Table 1 for details.…”

A fast and efficient algorithm for time synchronization in satellite quantum key distribution

“…Four single photon detectors with a timing jitter of 350 ps FWHM are used for detection of photons in four possible states of polarization. A more detailed description of the OGS can be found in previous publications [21][22][23].…”

“…All that is to be done is to split communication time into short time intervals so that the change of Doppler shift within these time periods can be neglected. Then, it is necessary to find 𝐶 𝑘 for each time interval using (23) and finally calculate sequence numbers of quantum states.…”