Abase station, comprising: a base station indoor apparatus (820, 920) and a base station outdoor apparatus (810, 910), wherein the interface between the base station indoor apparatus (820, 920) and the base station outdoor apparatus (810, 910) is a common public radio interface, CPRI; wherein: the base station outdoor apparatus comprises: a ground service antenna (811, 911), a satellite antenna (812, 912), a satellite signal processing module configured to perform decoding processing on a satellite radio frequency signal received by the satellite antenna to obtain a reference clock source signal, and a ground service processing module (813, 913) configured to perform demodulation processing on a modulation signal received by the ground service antenna; characterized in that the ground service processing module is further configured to perform phase discrimination processing on a current system clock signal and the reference clock source signal that is obtained by the satellite signal processing module to obtain a phase difference, to generate a data packet carrying the phase difference, to perform CPRI framing on the data packet to obtain a data frame, and to send the data frame to the base station indoor apparatus through the CPRI; and the base station indoor apparatus comprises: a service processing module (821, 921), configured to receive the data frame through the CPRI, to perform deframing processing on the data frame to obtain the data packet carrying the phase difference, to obtain the carried phase difference from the data packet, and to perform phase-locked tracking according to the phase difference, so as to obtain a calibrated system clock signal. a base station indoor apparatus (820, 920) and a base station outdoor apparatus (810, 910), wherein the interface between the base station indoor apparatus (820, 920) and the base station outdoor apparatus (810, 910) is a common public radio interface, CPRI; wherein: the base station outdoor apparatus comprises: a ground service antenna (811, 911), a satellite antenna (812, 912), a satellite signal processing module configured to perform decoding processing on a satellite radio frequency signal received by the satellite antenna to obtain a reference clock source signal, and a ground service processing module (813, 913) configured to perform demodulation processing on a modulation signal received by the ground service antenna; characterized in that the ground service processing module is further configured to perform phase discrimination processing on a current system clock signal and the reference clock source signal that is obtained by the satellite signal processing module to obtain a phase difference, to generate a data packet carrying the phase difference, to perform CPRI framing on the data packet to obtain a data frame, and to send the data frame to the base station indoor apparatus through the CPRI; and the base station indoor apparatus comprises: a service processing module (821, 921), configured to receive the data frame through the CPRI, to perform deframing processing on the data frame to obtain the data packet carrying the phase difference, to obtain the carried phase difference from the data packet, and to perform phase-locked tracking according to the phase difference, so as to obtain a calibrated system clock signal.