NONBREAK CLOCK TIMING CONTROL SYSTEM OF SATELLITE COMMUNICATION SYSTEM

摘要

PURPOSE:To perform breakless switching by controlling the output phase of an oscillator stepwise according to the extent of a phase error of a clock when a signal is transmitted through a stand-by system. CONSTITUTION:When the signal is transmitted from a transmission part 37, a synchronizing burst S1 and a data burst D1 are present in the burst transmission of a slave station. When an instruction for switching to a transmission part 38 is supplied, the slave station transmits an auxiliary burst S2' to a satellite through the transmission part 38 and the phase error is detected as well as the burst S1 to write phase error information in a phase error latch circuit 28. It is confirmed that the burst S2' is received at a specific frequency, and then the output phase of a variable phase and frequency oscillator 31 is varied stepwise with a phase control input on the basis of the contents of the circuit 28 to update the contents of a frequency control input from a phase error latch 27 to a circuit 28. Therefore, the transmission parts are switched without any break.