Time synchronization for quantum key distribution from ground to satellite

Airborne quantum key distribution: a review [Invited]

“…Assume that the quantum bit error rate (QBER) can be attributed to imperfections, including the source error e s , transmission error e t , measurement error e m , and the error caused by imprecise synchronization. The total error is expressed as [100] e = e s e m e t P noise 2P signal P noise ,…”

General relativistic theory for picosecond coordinate timing and time comparison of satellites under orbit perturbations

“…越来越多的空间科学任务提出了皮秒量级时间 比对精度要求 [1][2][3][4][5][6][7][8] . 欧洲空间原子钟组计划(Atomic clock ensemble in space, ACES)将在国际空间站上搭 载高精度原子钟实现皮秒量级的时间比对 [1][2][3] .…”

“…欧洲空间原子钟组计划(Atomic clock ensemble in space, ACES)将在国际空间站上搭 载高精度原子钟实现皮秒量级的时间比对 [1][2][3] . 广域 量子通信对时间比对精度也提出了更高的要求, 更 高精度的系统时间可以实现更远距离的广域量子通 信, 皮秒量级的时间比对精度将显著提高量子通信 的成码率 [4][5][6] . 其他基础空间科学研究, 如精细结构 常数测量、引力红移测量及深空探测等, 也提出了皮 秒量级的时间比对精度要求 [7][8] .…”

A Compact Readout Electronics for the Ground Station of a Quantum Communication Satellite

“…What is noteworthy is that the QBER depends on many factors [12] including source error, channel error, detection system error, system time resolution, background count rate, etc., and the final key rate depends on link efficiency, key extraction efficiency, average photon number per signal pulse, QBER, etc. [19].…”

“…[12]. High resolution TDC can improve the system's time measurement resolution, which then means the time coincidence window width can be set smaller, which results in a better signal to noise ratio (SNR) with more noise eliminated.…”