Title :
Method for block synchronisation in optical PPM
Author_Institution :
NTT Commun. Sci. Labs., Kyoto, Japan
fDate :
12/1/1993 12:00:00 AM
Abstract :
A method for block synchronisation in optical PPM is proposed. This method is an application of the synchronisation method for PN sequences normally used in spread spectrum communication systems. In this method, the phase of the synch signal is shifted little by little, with the synch decision process carried out on the receiving side until synchronisation is attained. The decision rule is based on the fact that the number of received pulses in each frame of the synch signal must be one and that the time when the pulse is received should not be in the pre-fixed prohibited frame slot, provided that synchronisation is established. This method´s synchronisation characteristics are investigated, and it is shown that block synchronisation can be established sufficiently with only 12.5% of additional prohibited slots
Keywords :
optical links; optical modulation; pulse modulation; synchronisation; PN sequences; additional prohibited slots; block synchronisation; optical PPM; optical pulse position modulation; pre-fixed prohibited frame slot; receiving side; spread spectrum communication systems; synch decision process; synch signal phase shifting;
Journal_Title :
Optoelectronics, IEE Proceedings J
