PCM Jitter Suppression by Scrambling

Jitter suppression in a chain of baseband PCM repeaters is studied. It is shown that a scrambler is very effective for systematic jitter suppression and that beyond 5 stages little additional suppression results. The probability of mark in the scrambler output converges to 0.5, independently of that in the input PCM signal. Experimental results confirm the analysis and show the ability of the scrambler to reduce the systematic jitter. The timing information disappearance of PCM repeatered lines when the scrambler is applied is also discussed.