Method and apparatus for controlling transmit power in wireless communication system

A user equipment (UE) for transmitting a physical uplink control channel (PUCCH) in a wireless communication system supporting multiple antennas, the UE comprising:

• a transceiver connected to a first antenna port and a second antenna port,
• wherein the transceiver is configured to use a multiple-antenna transmit mode for transmission using multiple antennas and a single-antenna transmit mode for transmission using a single antenna;
• and
• a controller configured to:
• determine that the multiple-antenna transmit mode is to be used for transmitting the PUCCH,
• determine a transmit power offset value to be added to a transmit power of the PUCCH depending on a PUCCH format to be used for transmitting the PUCCH using the first and second antenna ports,
• transmit, via the transceiver, the PUCCH by using a first PUCCH resource through the first antenna port, and
• transmit, via the transceiver, the PUCCH by using a second PUCCH resource through the second antenna port,
• wherein the determined transmit power offset value is added to the transmit power of the PUCCH for transmitting the PUCCH using the first and second antenna ports.

A method for transmitting a physical uplink control channel (PUCCH) in a wireless communication system supporting multiple antenna, the method performed by a user equipment (UE) having a first antenna port and a second antenna port, the method comprising:

• determining, by the UE, a number of antenna ports to be used for transmitting the PUCCH;
• selecting, by the UE, one value among a pre-stored integer value and higher layer signaled integer values for power offset based on the number of the antenna ports to be used for transmitting the PUCCH;
• transmitting the PUCCH by using a first PUCCH resource through the first antenna port;
• and
• transmitting the PUCCH by using a second PUCCH resource through the second antenna port,
• wherein the selected power offset value is added to a transmit power for transmitting the PUCCH using the first and second antenna ports.