Physical downlink control channel sending method and base station for cross-carrier scheduling

The invention discloses a PDCCH (Physical Downlink Control Channel) sending method and a base station for cross-carrier scheduling. The method comprises the following steps that: in FDD (Frequency Division Duplex) system, the base station configures a downlink component carrier configured to UE (User Equipment) as a component carrier of the UE for implementing cross-carrier scheduling, wherein the uplink component carrier corresponding to the downlink component carrier is configured to the UE; the base station sends PDCCH to the UE on the downlink component carrier; the UE sends PUSCH (Physical Uplink Shared Channel) scheduled by the PDCCH to the base station on the uplink component carrier when the PDCCH triggers an aperiodic CSI (Channel State Information) report; or, the base station sends PDCCH to the UE on the downlink component carrier; and the UE sends SRS (Sounding Reference Signal) triggered by the PDCCH to the base station on the uplink component carrier when the PDCCH triggers an aperiodic SRS report.