大气激光应急通信系统中的锁相环设计

Design of digital phase-locked loop of atmospheric laser emergency communication system

在传统锁相环的基础上,提出并设计了一种数字锁相环,其在大气激光应急通信系统中的功能是用输入信号预处理得到的准同步信号去同步当地时钟信号,使之相位保持一致。该数字锁相环采用闭环反馈跟踪方法,并用 CPLD 器件予以实现。在 MAX+PLUSⅡ环境下的仿真试验表明,该锁相环锁相误差小、抖动小、可靠性高;与传统锁相环相比,该设计编程方便,工作可靠。

A DPLL (Digital Phase-Locked Loop) is designed on the basis of traditional phase-locked loop. Its function in atmospheric laser emergency communication system is to synchronize the quasi-synchronous signal obtained from preprocessing input signal with local clock signal and let their phases consistent. A tracking method with closed-loop feedback is adopted in the DPLL and it is realized by CPLD devices. The simulation experiments under MAX+PLUS II show that the DPLL is characteristic of small phase error, small jitter and high reliability. Compared with traditional phase- locked loop, the design has a convenient programming and reliable operating performance.