A method is provided for determining transmit power of an uplink control channel of a user equipment to which two cells having different uplink (UL)-downlink (DL) configurations are assigned. A larger value between N1, the number of downlink subframes corresponding to a subframe n of a first cell having a first UL-DL configuration, and N2, the number of downlink subframes corresponding to a subframe n of a second cell having a second UL-DL configuration is chosen. A parameter value is determined based on the chosen value.