降低SDH网络指针调整引入抖动的有效方法

Efficient Methods to Reduce Jittering Induction in Pointer Adjustment in SDH Networks

本文首先介绍了抖动的基本概念以及ＳＤＨ系统指针调整引入抖动的机理；接着着重讨论了降低ＳＤＨ网络指针调整引入抖动的原理并给出ＰＬＬ型去同步器和两种新型去同步器；最后指出采用上述原理的去同步器，在其ＳＤＨ系统中高达４．６ｐｐｍ时钟频漂情况下可使输出抖动降至０．６ＵＩ以下。

First,the basic concepts of jittering and the mechanism of jittering induction in pointer adjustment in SDH system are imtroduced .Then,the principle of reducing jittering induction in pointer adjustment in SDH network is addressed; and the PLL-type desynchronizer and two new-type desynchronizers are proposed.Finally,it is pointed out that the use of the desynchronizer based on the above principle in the presence of clock frequency offset up to 4. 6ppm can lower the peak-to-peak jittering to under 0.6UI.