The average power density spectra of additive scrambler signals and their versions in AMI code

The scrambler outlet spectra, the AMI coding outlet spectra and their variations as a function of the scrambler inlet signal symbol statistics are studied for repeater design in a 565 Mb/sec coaxial cable data system. Expressions for the autocorrelation and the average power density spectra are obtained assuming that the characteristic polynomial of the scrambler is primitive and that the source is stationary and ergodic. It is shown that distortion produced by the discrete components results in jitter by amplitude to phase conversion. At the output of the AMI coder, when the probability of the zero symbols approachs one, the performance of the additive scrambler introduces an overload of the automatic gain control of the equalizing amplifier.