AI 中文总结
研究非平稳信道如卫星链路的量子密钥分发问题，利用混合鞅技术引入紧密集中不等式，相比现有方法更优，在卫星QKD波动损耗模拟中可大幅减少所需传输信号最小数量。
AI 中文摘要
在诸如卫星链路等非平稳信道上的量子密钥分发（QKD），其传输窗口短、损耗高且波动强烈，导致检测事件稀疏。许多QKD协议中需用非独立同分布统计不等式分析这些数据，现有方法对小样本规模变宽松或严重依赖微调，信道建模错误时估计不佳。我们用混合鞅技术引入紧密集中不等式，在信道模型准确时保持敏锐度，对模型不匹配也稳健。在卫星QKD波动损耗的实际模拟中，所得界限可将所需传输信号的最小数量减少超70%。
英文摘要
Quantum key distribution (QKD) over non-stationary channels, such as satellite links, is characterized by short, high-loss, and strongly fluctuating transmission windows that produce sparse detection events. In many QKD protocols, these data must be analyzed using non-IID statistical inequalities, yet existing methods either become loose for small sample sizes or heavily rely on fine-tuning, yielding poor estimates when the optical channel is mis-modeled. Using mixture martingale techniques, we introduce tight concentration inequalities that retain sharpness when the channel model is accurate, while remaining robust to model mismatch. In realistic simulations of satellite QKD with fluctuating loss, the resulting bounds can reduce the minimum required number of transmitted signals by more than $70\%$.
