空地量子密钥分发网络中数据协调方案

在空地量子密钥分发网络中，空中平台的硬件设备限制使得后处理阶段数据传输速度以及处理能力减弱。针对空中平台的特性，提出了一种适合空地量子密钥分发网络的数据协调方案。首先，采用量子纠错技术减少原始密钥的误码率；其次，设计了一种新方法用来制备低密度奇偶校验（LDPC）译码算法中的随机置换序列；最后，兼顾LDPC译码算法性能和算法硬件实现复杂度，选取了软判决中最小和译码算法。仿真分析表明:量子纠错处理后的原始密钥误码率明显减少，错误率由29.5%减少为4.4%；使用新方法生成随机置换序列，在保证序列随机性的前提下效率提升，生成长度为10 000的随机置换序列所用时间约为0.019 s；LDPC译码算法中最小和译码算法性能适中且硬件实现简单。 

Data reconciliation scheme for space-ground quantum key distribution network

In the space-ground quantum key distribution network, the hardware device limitation of the air platform makes the data transmission speed and processing capability of the post-processing stage weakened. Aimed at the characteristics of free space and airborne platform, this paper proposes a data reconciliation scheme suitable for the space-ground quantum key distribution network. Firstly, quantum error correction techniques are used to reduce the bit error rate of the original key. Then, a new method is designed to prepare random sequences in Low Density Parity-Check (LDPC) algorithm. Finally, considering the performance of the LDPC decoding algorithm and the hardware implementation complexity of the algorithm, Min-Sum decoding algorithm in the soft decision is selected. The simulation analysis shows that the error rate of the original key after quantum error correction processing is significantly reduced, and the error rate is reduced from 29.5% to 4.4%. Using a new method to generate a random sequence, the efficiency is improved under the premise of ensuring the randomness of the sequence. The time to generate a random replacement sequence with a length of 10 000 is about 0.019 s. The Min-Sum decoding algorithms in the LDPC decoding algorithm are moderate in performance and simple in hardware implementation.