超大规模集成电路(VLSI)构成数字用户环收发器时,其定时恢复必须有多种信号处理功能,采样数据法是得到这种必要的信号处理功能的最实用方法。本文介绍的采样数据定时恢复技术可用于回波抵消和时间压缩复接系统。采用波特率采样的定时恢复,结合使用专门的脉冲成形和定时功能,就能充分满足这种应用情况下对定时恢复的各项指标,它恢复的定时脉冲具有最小的前置游标串号干扰,而且可能将判决反馈均衡器和回波抵消器结合起来用,缩短收敛时间和增大步长。脉冲成形功能可在发端用数字编码实现,或在收端用模拟滤波来完成,采用后一种方法时,发送脉冲是与各种常规方法相一致的,文章提出的部分响应线路编码是一种特殊形式的AMI编码,如果按双电平信号检测,它对线路损伤就不怎么敏感,文章报导了各种电缆结构,其中有些有桥接支线情况下,分析、仿真和实验测量的性能。通讨对抖动性能的分析,导出几种降低抖动幅度的设计方法. Very large scale integration (VLSI) form digital user ring transceiver, the timing recovery must have a variety of signal processing functions, sampling data method is to obtain the necessary signal processing functions of the most practical method. This article describes the sampling data timing recovery techniques can be used for echo cancellation and time compression multiplexing system. Using baud rate sampling timing recovery, combined with the use of specialized pulse shaping and timing functions, can fully meet the application of the timing recovery of the indicators, which restore the timing pulse with the smallest pre cursor serial number interference , And may combine the decision feedback equalizer with the echo canceller to shorten the convergence time and increase the step size. The pulse shaping function can be implemented by digital coding at the beginning or by analog filtering at the receiver. The latter method, the sending pulse is consistent with various conventional methods, the partial response line coding proposed by the article is a The special form of AMI coding, which is less sensitive to line impairments if it is detected as a two-level signal, reports the performance of various cable structures, some of which have analytical, simulation and experimental measurements in the case of bridge branches. Discuss the jitter performance analysis, derived several methods to reduce the jitter amplitude of the design.