SYNCHRONIZATION OF REPLACABLE TACTICAL OSCILLATORS WHEN TRANSMITTING DIGITAL SIGNALS.

摘要

Transmission lines for digital signals may include a large number-for example, several hundred-of intermediate generators. In this case, telemetering units are provided at the end points and at intermediate points, by means of which the digital telemetry signals are generated and sent over the transmission lines together with the digital information signals. In the event of interference, a problem arises, due to the fact that the telemetry signal that is needed to identify the interference is only available after a comparatively long time. Therefore, according to the invention, a method is recommended for the initial synchronization, at bit rate, of the pulse generators which generate the bit pulse in the telemetering units. The pulse generation is accomplished with a phase-control loop which generates a signal pulse with a comparatively high frequency. This high frequency is broken down by a resettable frequency divider to the pulse frequency by setting the frequency divider with the first correct sync word recognition. This results in an intermediate synchronization.