A user equipment comprising: a scheduling module configured to: receive, from a base station, downlink control information, DCI, in a first subframe of a primary serving cell, PCell, of the base station, the DCI to include a carrier indication field, CIF, value and an indicator to indicate a downlink resource of a physical downlink shared channel, PDSCH, transmission that is to include data directed to the user equipment; access mapping information based on the CIF value and a carrier aggregation level, wherein the carrier aggregation level indicates how many component carriers are configured between the base station and the user equipment; determine, based on a predetermined subframe pairing and the CIF value, that the PDSCH transmission is in a subframe of a secondary serving cell, Scell, wherein the predetermined subframe pairing comprises a first paired subframe and a second paired subframe of the Scell, both paired to the first subframe of the Pcell; determine, based on the mapping information, whether the indicator applies to the first paired subframe of the predetermined subframe pairing, the second paired subframe of the predetermined subframe pairing, or to both the first and second paired subframes of the predetermined subframe pairing; and a decoder module configured to decode the downlink resource of the PDSCH transmission based on the indicator and said determination that the PDSCH transmission is in a subframe of the Scell. a scheduling module configured to: receive, from a base station, downlink control information, DCI, in a first subframe of a primary serving cell, PCell, of the base station, the DCI to include a carrier indication field, CIF, value and an indicator to indicate a downlink resource of a physical downlink shared channel, PDSCH, transmission that is to include data directed to the user equipment; access mapping information based on the CIF value and a carrier aggregation level, wherein the carrier aggregation level indicates how many component carriers are configured between the base station and the user equipment; determine, based on a predetermined subframe pairing and the CIF value, that the PDSCH transmission is in a subframe of a secondary serving cell, Scell, wherein the predetermined subframe pairing comprises a first paired subframe and a second paired subframe of the Scell, both paired to the first subframe of the Pcell; determine, based on the mapping information, whether the indicator applies to the first paired subframe of the predetermined subframe pairing, the second paired subframe of the predetermined subframe pairing, or to both the first and second paired subframes of the predetermined subframe pairing; and receive, from a base station, downlink control information, DCI, in a first subframe of a primary serving cell, PCell, of the base station, the DCI to include a carrier indication field, CIF, value and an indicator to indicate a downlink resource of a physical downlink shared channel, PDSCH, transmission that is to include data directed to the user equipment; access mapping information based on the CIF value and a carrier aggregation level, wherein the carrier aggregation level indicates how many component carriers are configured between the base station and the user equipment; determine, based on a predetermined subframe pairing and the CIF value, that the PDSCH transmission is in a subframe of a secondary serving cell, Scell, wherein the predetermined subframe pairing comprises a first paired subframe and a second paired subframe of the Scell, both paired to the first subframe of the Pcell; determine, based on the mapping information, whether the indicator applies to the first paired subframe of the predetermined subframe pairing, the second paired subframe of the predetermined subframe pairing, or to both the first and second paired subframes of the predetermined subframe pairing; and a decoder module configured to decode the downlink resource of the PDSCH transmission based on the indicator and said determination that the PDSCH transmission is in a subframe of the Scell.