Carrier synchronizing system for locking a remotely located carrier generator to a reference carrier generator at a base station

摘要

The base station comprises a reference carrier generator and a synchronized carrier generator is provided in at least one remote station. Carrier synchronizing information is transmitted from the base station to the remote station and the synchronized carrier and information to be transmitted therewith are transmitted from the remote station to the base station. The base station has a periodically variable phase shifter to an input of which the synchronized carrier is applied, an output being coupled to a phase comparator to which in addition the reference carrier wave is applied. During first periods the phase shifter is subjected to a continuous phase shift. Second periods present in the first period are counted by a counter which is resettable under the control of the first periods. The counter is stopped by the phase comparator when a reference phase is reached during the phase shift. The counting result is numerical carrier synchronizing information, as required for a micro-processor or a micro-computer. The phase shift is effected incrementally, to an increasingly smaller portion of the carrier wave period near the zero phase.