Method for the reduction of phase noise introduced by the SDH network (Synchronous Digital Hierarchy Network) by pointer justification and integrated circuits for the implementation of the method

摘要

A method and apparatus for reducing the phase noise introduced by pointer justification from a synchronous digital hierarchy network in a transmitted numerical signal. In the method and apparatus, occasional redundancies associated with bit justifications and fixed redundancies are combined with occasional prefiltered redundancies associated with the pointer justifications, and the combined signal is filtered in an analog phase locked loop. The occasional redundancies associated with the pointer justifications and at least part of the fixed redundancies with or without bit justifications are prefiltered in two stages, and the prefiltered signals are combined with the occasional redundancies associated with the bit justifications whenever these occasional redundancies are not prefiltered.