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同步数字系列（ＳＤＨ）中的指针调整引入了８ｂｉｔ或２４ｂｉｔ的大幅度抖动。为了处理这一抖动，提出了一种数字化处理方法——自适应预测法，可以作为预处理方法应用于ＳＤＨ中的四次群时钟恢复。该方法在一个统计周期内统计指针调整和码速调整的次数，并根据统计结果，在下一个周期内自适应地预测出四次群支路时钟。该时钟不含指针抖动，便于利用模拟锁相环进行最终处理，得到均匀的四次群时钟。从该方法的基本原理，以及对它的静态抖动和抖动转移性能分析中可知，相对于以往的减小指针抖动的方法，如比特泄漏法等，自适应预测法具有输出抖动小，抖动转移性能好，捕捉范围宽等特点。
Pointer adjustment in the Synchronous Digital Hierarchy (SDH) introduces a large jitter of 8 bits or 24 bits. In order to deal with this jitter, a digital processing method, adaptive prediction method, is proposed, which can be used as a preprocessing method for quad-group clock recovery in SDH. The method counts the number of pointer adjustment and code rate adjustment in a statistical period, and according to the statistical result, predicts the fourth-group branch clock adaptively in the next period. The clock without pointer jitter, easy to use analog phase-locked loop for final processing, get a uniform four-group clock. From the basic principle of this method and its analysis of static jitter and jitter transfer performance, we can see that compared with the previous methods of reducing jitter of pointers, such as bit leakage method, adaptive predictive method has the advantages of small output jitter, jitter transfer performance Good, capture a wide range of features.