Method and apparatus for transmitting reception acknowledgement information in wireless communication system

A user equipment configured for transmitting a reception acknowledgement for hybrid automatic repeat request (HARQ) in a wireless communication system, the user equipment comprising:

• a radio frequency (RF) unit configured for transmitting and receiving a radio signal;
• and
• a processor operably coupled to the RF unit and configured for:
• receiving downlink control information (DCI) on a physical downlink control channel (PDCCH) through one of a first component carrier and a second component carrier, the DCI including a downlink resource allocation;
• receiving a downlink transport block in accordance with the downlink resource allocation through one of the first component carrier and the second component carrier;
• and
• transmitting a ACK/NACK signal for the downlink transport block on a physical uplink control channel (PUCCH),
• wherein if the downlink transport block is received through the first component carrier, a resource used for the PUCCH is determined from a resource used for the PDCCH,
• wherein if the downlink transport block is received through the second component carrier, the resource used for the PUCCH is determined from one of reserved resources which are configured by a Radio Resource Control (RRC) message, and
• wherein the resource used for the PUCCH is associated with an orthogonal sequence with which the ACK/NACK signal is spread.