Digital receiver for time multiplexed digital exchange - initiates synchronisation process when consecutive synchronisation words occur at wrong instants

摘要

The digital receiver detects the appearance of a sync. word prefixed to each signal block and thereby ensures synchronised reception despite lines of different lengths. A counter is started at the beginning of the receiver's received time-window. The count that this counter has reached at the moment the sync. word is detected is stored and used in the next receive time-window as a reference fo comparing with a new count. If consecutive counts are not the same the synchronisation process is initiated.