A user equipment (UE) is provided for transmitting an uplink signal in a wireless communication system The UE sets up a sounding reference signal (SRS) configuration for a first serving cell that includes information for an SRS transmission, and determines an SRS subframe in which an SRS and a physical uplink shared channel (PUSCH) for the first serving cell are simultaneously triggered according to the SRS configuration. If a SRS transmission on the SRS subframe for the first serving cell is overlapped with an uplink transmission for a second serving cell, the UE transmits the SRS in the SRS subframe if a total uplink transmission power does not exceeds the UE's maximum transmit power on the overlapped portion. If the SRS is triggered by the SRS configuration and timing advance groups are configured to the UE, the UE transmits the PUSCH on the SRS subframe for the first serving cell.