Unidirectional time-service discipline system and method for Beidou-I satellite system

The invention discloses a unidirectional time-service discipline system and method for a Beidou-I satellite system. The method comprises the following three steps: crystal oscillation offset detection based on a DSP (Digital Signal Processor): at the time of each frame, the DSP automatically detects the offset of the actual crystal oscillation value relative to a theoretical value, stores the offset in a register, and transfers the offset to a crystal oscillation correction module of an FPGA (Field Programmable Gate Array) when the time of next frame comes; crystal oscillation correction: theFPGA monitors the satellite status in real time, the crystal oscillation correction module is switched into a time-service mode when satellite is unlocked or malfunctioning, and then a stable signal based on one pulse per second (1PPS) is generated within a short time by virtue of internal time-service counters A and B of a time-service module; and time service: the time of each frame of the internal time-service counters A and B is synchronized with that of time-service time counters A and B at one time. The unidirectional time-service discipline system and method have the beneficial effectsof solving the problems of low time-service precision, poor stability and the like resulting from faults of satellite beams of the Beidou-I satellite system within a short time, and improving the time-service precision and the stability.