空间信道离散调制连续变量量子密钥分发可行性分析  

Feasibility analysis study of discrete modulation continuous variable quantum key distribution for spatial channels

作　　者：孙新 郭俊杰 陈宇杰 程锦 刘奥 刘文博 尹鹏 陈兰剑 吴田宜 东晨 SUN Xin;GUO Junjie;CHEN Yujie;CHENG Jin;LIU Ao;LIU Wenbo;YIN Peng;CHEN Lanjian;WU Tianyi;DONG Chen(Institute of Information and Communication,National University of Defense Technology,Wuhan 430030,China)

机构地区：[1]国防科技大学信息通信学院,武汉430030

出　　处：《物理学报》2025年第9期67-75,共9页Acta Physica Sinica

基　　金：湖北省自然科学基金(批准号:2024AFB991)资助的课题.

摘　　要：在光纤信道中,连续变量量子密钥分发(continuous-variable quantum key distribution,CV-QKD)协议已经展现出获得更高安全码率的能力,但是CV-QKD协议可容忍的信道衰减相对较低,空间衍射、大气折射、信号衰减和湍流等实际因素都会影响空间信道中CV-QKD协议的可行性.本文研究了实际空间信道环境下离散调制CV-QKD协议的可行性,分析了空间衍射和大气衰减、湍流信道退化模型对于空间信道离散调制CV-QKD协议的影响,讨论了卫星轨道高度、天顶角、接收器孔径、束腰尺寸和过量噪声等实际参数对空间离散调制CV-QKD的密钥生成率影响,搭建了星地动态运动场景仿真分析了实际环境下空间信道离散调制CV-QKD协议的可行性,仿真结果可为空间信道离散调制CV-QKD实验的设计和优化提供参考.Continuous variable quantum key distribution(CV-QKD)has emerged as a promising candidate for quantum-secure communication due to its experimentally demonstrated high key rates in fiber-optic channels.However,the feasibility of discrete modulation CV-QKD in satellite-to-ground downlinks remains an open question due to practical challenges such as high transmission loss,limited communication windows,and atmospheric turbulence.In this work,a comprehensive framework is proposed to evaluate the feasibility of discrete modulation CV-QKD by integrating orbital dynamics and atmospheric channel models,and to comprehensively analyze the influence of the parameter space on free-space discrete modulation CV-QKD.To achieve this,a free-space CV-QKD simulation platform is employed,which calculates the elevation angle and transmission distance based on precise orbital models,thereby providing a more practical assessment of the key rate for discrete modulation CV-QKD.Simulation results verify the feasibility and practicality of discrete modulation CV-QKD in satellite-based quantum communication systems.Furthermore,the critical factors influencing the key rate performance are identified,and parameter optimization strategies are proposed,providing theoretical support for realizing the future satellite-to-ground discrete modulation CV-QKD.

关 键 词：空间信道 连续变量量子密钥分发 星地下行链路 离散调制 

分 类 号：TN918[电子电信—通信与信息系统]