设计并实现了一种并行循环移位比较的帧同步方式,将其应用于传输速率为2.5Gbit·s-1的大气激光通信脉冲位置调制(PPM)系统中,论述了该帧同步的工作原理,并分析了其同步性能。采用特定帧头同步序列提高了系统对大气信道帧同步的容错能力,在信道状态变差时通过适当减小检测阈值可保持较高的同步概率。理论及仿真结果表明,该同步方案可在高速PPM光通信中实现帧同步,对应于大气信道3种不同的情形,检测阈值分别取14、7~9、10~13时可使系统保持较好的工作性能。 This paper designs and implements a frame synchronization method with parallel cyclic shift comparison, and applies it to pulse laser position modulation (PPM) system of atmospheric laser communication with a transmission rate of 2.5Gbit · s-1. The principle of frame synchronization is discussed , And analyzed its synchronization performance. Using a specific frame header synchronization sequence improves the system’s fault tolerance of atmospheric channel frame synchronization. When the channel status is worsened, the synchronization probability can be kept lower by properly reducing the detection threshold. Theoretical and simulation results show that the synchronization scheme can achieve frame synchronization in high speed PPM optical communication, which corresponds to three different situations of the atmospheric channel. The detection threshold of 14,7 ~ 9 and 10 ~ 13 respectively can keep the system well Work performance.