Patent ID: 8687579

Claim:
A method for detecting downlink control information, comprising: when scheduling across carriers is enabled, determining by a user equipment a user-specific search space monitoring a physical downlink control channel (PDCCH) according to component carrier indexes, wherein each component carrier corresponds to one user-specific search space; wherein and the component carrier indexes include indexes of various component carriers implementing scheduling across carriers and component carriers being scheduled across carriers; wherein, when sizes of the information domains of downlink control information formats configured on the component carriers implementing scheduling across carriers and component carriers being scheduled across carriers are different, after the step of determining by a user equipment a user-specific search space monitoring a physical downlink control channel according to component carrier indexes, the method further comprises: monitoring the PDCCH by the user equipment for the various component carriers on an independent search space of the various component carriers; or, when sizes of the information domains of downlink control information formats configured on the component carriers implementing scheduling across carriers and component carriers being scheduled across carriers are the same, after the step of determining by a user equipment a user-specific search space monitoring a physical downlink control channel according to component carrier indexes, the method further comprises: monitoring the PDCCH by the user equipment for the various component carriers on a shared search space, with the shared search space including search space composed of the search spaces of the various component carriers; or, when scheduling across carriers is enabled, if size of information domain of a downlink control information format (DCI format) under a user-specific search space condition is the same as that of the DCI format under a common search space condition, and the DCI format under the user-specific search space condition and the DCI format under the common search space condition employ the same cyclic redundancy checksum scrambled by a radio network temporary identifier, the PDCCH monitoring is carried out only according to the DCI format of the common search space, or the PDCCH monitoring is carried out only according to the DCI format of the user-specific search space.