提出了一种基于光子到达时间测量的光子探测阵列信号时隙同步方法。通过测量每个支路不同光子的到达时间, 得到每个光子的到达时间相对于脉冲位置调制时隙位置的偏移量, 统计得到不同偏移量处的光子分布。在频偏存在的情况下, 光子分布更加平坦; 在初始相偏存在的情况下, 光子分布峰值会偏离中心位置。把均方误差或二阶矩作为不同频偏和初始相偏情况下同步程度的衡量标准, 利用搜索的方式实现时隙同步。仿真结果表明, 在计数时钟频率为时隙时钟频率两倍及以上的情况下, 所提方法能实现时隙同步。

A synchronized method of photon detection array signal slot based on measurement of photon arrival time is proposed. Firstly, to obtain the offset of the arrival time of each photon relative to the position of the pulse position modulation slot, we measure the arrival time of different photons in each branch, and finally the photon distribution at different offsets is obtained statistically. In the presence of frequency offset, the photon distribution becomes much flatter. When the initial phase shift exists, the peak of the photon distribution can deviate from the center position. Then the mean square error or second moment is used as the standard of the synchronization under different frequency offsets and initial phase offsets, and the searching method is used to achieve the slot synchronization. The simulation results show that the proposed method can achieve the slot synchronization when the counting clock frequency is twice or more than the slot clock frequency.