Downlink control information transmitting method and base station, and downlink control information receiving method and user device

A method of receiving, by a user equipment using a plurality of carriers, downlink control information in a wireless communication system, the method comprises:

• receiving, by the user equipment, a first physical downlink control channel (PDCCH) carrying first control information, which is for reception of a first physical downlink shared channel (PDSCH) and includes a carrier indication field set to indicate a first carrier among the plurality of carriers, and a second PDCCH carrying second control information, which is for reception of a second PDSCH and includes a carrier indication field set to indicate a second carrier among the plurality of carriers, through the first carrier in a subframe n;
• receiving, by the user equipment, the first PDSCH carrying first downlink data through the first carrier based on the first control information in the subframe n;
• and
• receiving, by the user equipment, the second PDSCH carrying second downlink data through the second carrier based on the second control information in a subframe n+k when the second carrier is different from the first carrier and carries no PDCCH,
• wherein k is equal to 1or 2, and
• wherein the subframe n and the subframe n+k are downlink subframes.

A base station of transmitting downlink control information to a user equipment using a plurality of carriers in a wireless communication system, the base station comprises:

• a transmitter configured to transmit radio signals through the plurality of carriers;
• and
• a processor, connected to the transmitter, configured to control the transmitter to transmit a first physical downlink control channel (PDCCH) carrying first control information, which is for transmission of a first physical downlink shared channel (PDSCH) and includes a carrier indication field set to indicate a first carrier among the plurality of carriers, and a second PDCCH carrying second control information, which is for transmission of a second PDSCH and includes a carrier indication field set to indicate a second carrier among the plurality of carriers, through the first carrier to the user equipment in a subframe n;
• to transmit the first PDSCH carrying first downlink data through the first carrier based on the first control information to the user equipment in the subframe n;
• and to transmit the second PDSCH carrying second downlink data through the second carrier based on the second control information to the user equipment in a subframe n+k when the second carrier is different from the first carrier and carries no PDCCH,
• wherein k is equal to 1or 2, and
• wherein the subframe n and the subframe n+k are downlink subframes.

A user equipment, using a plurality of carriers, of receiving downlink control information in a wireless communication system, the user equipment comprises:

• a receiver configured to receive radio signals through the plurality of carriers;
• and
• a processor configured to control the receiver to receive a first physical downlink control channel (PDCCH) carrying first control information, which is for reception of a first physical downlink shared channel (PDSCH) and includes a carrier indication field set to indicate a first carrier among the plurality of carriers, and a second PDCCH carrying second control information, which is for reception of a second PDSCH and includes a carrier indication field set to indicate a second carrier among the plurality of carriers, through the first carrier in a subframe n;
• to receive the first PDSCH carrying first downlink data through the first carrier based on the first control information in the subframe n;
• and to receive the second PDSCH carrying second downlink data through the second carrier based on the second control information in a subframe n+k when the second carrier is different from the first carrier and carries no PDCCH,
• wherein k is equal to 1or 2, and
• wherein the subframe n and the subframe n+k are downlink subframes.