Method and apparatus for transmitting reception confirmation response of user equipment in wireless communication system

A user equipment (UE), comprising:

• a transceiver configured to receive and transmit radio signals;
• and
• a processor connected to the transceiver,
• wherein the processor is configured to:
• control the transceiver to receive two transport blocks (TBs) through a downlink subframe of the first serving cell;
• control the transceiver to receive one TB through a downlink subframe of the second serving cell;
• and
• control the transceiver to transmit ACK/NACK information informing ACK/NACKs for the two TBs and the one TB through an uplink subframe of the first serving cell,
• wherein the ACK/NACK information informs the ACK/NACKs for the two TBs and the one TB by a combination of one resource selected from a plurality of candidate resources and two bits transmitted through the one resource, and
• wherein:
• when the UE is configured with a transmission mode that supports up to two TBs on the second serving cell,
• if the one TB is decoded successfully, the UE transmits first ACK/NACK information informing ‘two ACK/NACKs for the two TBs’ and ‘two ACKs for the one TB’ by a first combination of a first resource among the plurality of candidate resources and two bits, wherein the first resource is selected based on the ‘two ACK/NACKs for the two TBs’ and ‘two ACKs for the one TB’, or
• if the one TB is not decoded successfully, the UE transmits second ACK/NACK information informing ‘two ACK/NACKs for the two TBs’ and ‘two NACKs for the one TB’ by a second combination of a second resource among the plurality of candidate resources and two bits, wherein the second resource is selected based on the ‘two ACK/NACKs for the two TBs’ and ‘two NACKs for the one TB’.