Parameter Optimization Of Practical Quantum Key Distribution Network System

Quantum key distribution(QKD)is a safe and efficient telecommunication technology.Quantum channel and classical channel are both applied in QKD.Quantum channel is used to distribute key,and classical channel is used to transmit classical information.So,QKD combines the benefits of strong security of quantum channel and large bandwidth of classical channel.QKD has also become a popular study field of telecommunication.At present,there are still many difficulties in the theoretical research and practical application of QKD.One of the problems is that the performance of QKD protocol can not meet the requirements of large-scale applications.In this paper,we are committed to improving the performance of quantum key distribution protocols and optimizing the parameters of quantum key distribution protocols.There are mainly four aspects as follows:Firstly,the parameter optimization of the seven-intensity Measurement Device Independent Quantum Key Distribution(MDI-QKD)in asymmetric channel is analyzed,and the statistical fluctuation based on standard deviation analysis is considered.The asymmetric channel in different situations has been discussed,the intensity of signal state and decoy state are optimized respectively,and the conditions to improve the performance of the system in asymmetric channel are summarized.Secondly,three intensity decoy state Phase Matching Quantum Key Distribution(PM-QKD)protocol is discussed,and the finite size effect and source error based on standard deviation analysis are considered.The parameters of finite size effect and source error are analyzed.The signal state(decoy state)intensity is optimized,and the optimal signal state intensity and decoy state intensity are given.What’s more,five intensity decoy state PMQKD protocol is analyzed,which is an asymmetric version to the three-intensity decoy-state PM-QKD protocol.The intensity of the signal state and decoy state of the protocol are optimized,and The performance of the protocol under asymmetry channel is improved.Finally,the three-intensity decoy-state satellite-based PM-QKD system is introduced.This system is applied to the special case of the communication between low earth orbit quantum satellite and ground station.The parameters of the three-intensity satellite-based PMQKD system is discussed.The intensity of signal state and decoy state are both optimized to improve the performance of the system.These research can provide a reference for the development of MDI-QKD,PM-QKD and satellitebased QKD in the future.