激光通信数字环时隙同步器环路滤波器设计

以５１系列单片机为硬件平台，设计了均值法、三点法和筛选法三种数字环路滤波器算法，分析了采用这三种环路滤波器算法的数字锁相环时隙同步器的性能指标并进行了计算机仿真．仿真和实验结果表明，采用筛选法的时隙同步器具有较快的捕获速度和最好的抗噪性能，可用于强噪声环境下的激光水下通信系统

The Loop Filter in Digital Phase Locked Loop Time Slot Synchronizer for Underwater Laser Communication

In underwater laser communication with PPM, accurate time slot synchronizing signals are required. Such a time slot synchronizer can be realized with digital phase locked loop (DPLL). The anti noise ability of a DPLL depends on the loop filter. Three types of loop filter, the mean value filter, 3 spot filter and screening filter respectively are proposed. Theoretical analyses, computer simulations and experimental results concerning their performance are given. The synchronizer with screening filter has shorter acquisition time and best anti noise ability, and is ideal for use in underwater laser communication in a strong noise background.