A method of detecting a downlink control signal by a user equipment in discontinuous reception, DRX, mode in a carrier aggregation applied wireless communication system, comprising: configuring downlink control channel detection subframes in a time division duplex, TDD, primary cell and a frequency division duplex, FDD, secondary cell based on a specific uplink/downlink subframe configuration for the TDD primary cell; detecting the downlink control channel from one of the downlink control channel detection subframes through either the TDD primary cell or the FDD secondary cell while a preset DRX related timer defined by a subframe number unit is operating; and receiving a downlink data signal based on the detected downlink control channel, wherein the downlink control channel detection subframes in the FDD secondary cell comprise subframes on the FDD secondary cell matching locations of downlink subframes on the specific uplink/downlink subframe configuration or locations of special subframes, including a downlink pilot time slot, DwPTS, over a preset length, on the specific uplink/downlink subframe configuration, wherein the special subframe comprises the DwPTS, a guard period, GP, and an uplink pilot time slot, UpPTS, further wherein the specific uplink/downlink subframe configuration is an uplink/downlink subframe configuration having a maximum downlink subframe number among uplink/downlink subframe configurations assigned for the TDD primary cell of the user equipment when a detection of information on a valid uplink/downlink subframe configuration to change an uplink subframe of a system information block type1, SIB1 uplink/downlink subframe configuration to a downlink subframe is not successful, wherein the uplink/downlink subframe configurations assigned for the TDD primary cell of the user equipment includes at least one of the SIB1 uplink/downlink subframe configuration, a downlink hybrid automatic repeat and request, HARQ, reference configuration, and/or an uplink HARQ reference configuration. configuring downlink control channel detection subframes in a time division duplex, TDD, primary cell and a frequency division duplex, FDD, secondary cell based on a specific uplink/downlink subframe configuration for the TDD primary cell; detecting the downlink control channel from one of the downlink control channel detection subframes through either the TDD primary cell or the FDD secondary cell while a preset DRX related timer defined by a subframe number unit is operating; and receiving a downlink data signal based on the detected downlink control channel, wherein the downlink control channel detection subframes in the FDD secondary cell comprise subframes on the FDD secondary cell matching locations of downlink subframes on the specific uplink/downlink subframe configuration or locations of special subframes, including a downlink pilot time slot, DwPTS, over a preset length, on the specific uplink/downlink subframe configuration, wherein the special subframe comprises the DwPTS, a guard period, GP, and an uplink pilot time slot, UpPTS, further wherein the specific uplink/downlink subframe configuration is an uplink/downlink subframe configuration having a maximum downlink subframe number among uplink/downlink subframe configurations assigned for the TDD primary cell of the user equipment when a detection of information on a valid uplink/downlink subframe configuration to change an uplink subframe of a system information block type1, SIB1 uplink/downlink subframe configuration to a downlink subframe is not successful, wherein the uplink/downlink subframe configurations assigned for the TDD primary cell of the user equipment includes at least one of the SIB1 uplink/downlink subframe configuration, a downlink hybrid automatic repeat and request, HARQ, reference configuration, and/or an uplink HARQ reference configuration.