ON THE REAL JITTER ACCUMULATION IN THE REGENERATORS OF DIGITAL TRANSMISSION-SYSTEMS

According to the nearly 30 years old model of Byrne et al. the effective value of the phase jitter PHI(ai)BAR (p) at the output of the timing' filter in the i-th repeater of a digital transmission system continuously increases quite independent on the bandwidth of the filter, if only constant receiving jitter phi (p) will be assumed. 12 years ago Trondle et al. have qualitatively shown that the power density spectrum of the systematic receiving jitter in dependence on the data signal vanishs with the frequency. Therefore the accumulation tendency of the timing jitter PHI(ai)BAR(p) in accordance to the frequency response of the jitter transfer function could be considerably smaller than suspected. Using simulation techniques on large computers here will be shown that in regenerator chains not only the receiving jitter PHI(a1)BAR(p) but also the reduced ratio of the effective values of the systematic phase jitter PHI(ai)BAR(p) in the i-th and first repeater vanishs, if the relative bandwidth of the filter will be reduced more and more. Obviously the timing jitter does not unrestrictedly increase with i, using sufficient narrow-banded filters, but only for 100% and less.