Verfahren und Vorrichtung zur Rahmensynchronisation in einem Zeitmultiplexsystem

The method involves determining the time position of a digital character sequence received in a time slot using a synchronisation word of n successive characters. A fixed length window is set up about a point at which the frame structure is anticipated according to the synchronisation word. A partial sequence within the window is compared with a stored reference word until a positive comparison is achieved, whereupon the position of the synchronisation word is used for frame synchronisation, otherwise the frame is rejected as unsynchronised. The received digital character sequence is sampled with a factor k, k sub-sequences are stored and compared with the reference word. Positive or negative entries are made for the associated times and the synchronisation sampling phase is derived from the positions of at least two entries.