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Timing Errors in a Chain of Regenerative Repeaters, III

01 July 1964

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l.i Purpose Pulse regeneration is an attractive feature of digital communication systems. A regenerator or a regenerative repeater m u s t : (i) detect t h e presence or absence of a pulse at certain time instants which are, ideally, 1481 1482 T H E BELL SYSTEM TECHNICAL J O U R N A L , JULY 1964 multiples of the basic pulse repetition period, (ii) regenerate the pulse shapes, and (m) retime these pulses so they occur at appropriate instants of time in t h e outgoing signal. In practice, errors in detection due to noise, distortion, etc. in t h e system and errors in retiming the signal impose limitations 011 the operation of such systems. Except for noise which may lead to t h e detection of a pulse where no pulse exists in t h e original signal and vice versa, t h e imperfections in the system show up as a jittering of the pulse positions in the outgoing signal. In self-timing repeaters, 1 t h e jitter from all sources except random noise is also dependent 011 the signal itself. 2 Several workers have investigated many different aspects of the timing jitter problem. 1 - 9 We study here the signal-dependent jitter due to repeated regeneration. This article leans quite heavily on our previous discussion, and in fact it supplements as well as complements t h e previous results referred to in this article as P a r t s I and II. 3 1.2 Background