Jisuanji fangzhen
Analysis and Simulation of Quantum Bit Error Rate and Sifted Key Rate for Satellite-Earth Quantum Key Distribution System
Hongen Zhong
Abstract
Quantum bit error rate is an important operating parameter in quantum key distribution system.Aiming at satellite to earth quantum key distribution system,an quantum bit error rate model was established with several factors,such as background light,quantum polarization degradation,polarization misalignments and photodetector dark current.Calculation formula of quantum bit error rate and sifted key bits was given,as well as the numerical simulation results for laser links between ground and a 300km altitude satellite.This study shows that,when the pulse frequency is set at 30kHz and with good weather conditions,the quantum polarization degradation is the main factor that contributes to error bit,which provides the significant instruction for the design of satellite-earth quantum key distribution system.