A method and communication apparatus for controlling transmission powers in a wireless communication system supporting a plurality of component carriers are described. When a sounding reference symbol (SRS) transmission overlaps with a physical uplink shared channel (PUSCH) transmission and a physical uplink control channel (PUCCH) transmission in a time domain, a check is made as to whether a total of a PUSCH transmission power for the PUSCH transmission on a first component carrier, a PUCCH transmission power for the PUCCH transmission on the first component carrier and a SRS transmission power for the SRS transmission on a second component carrier exceeds a maximum transmission power configured for the communication apparatus. The SRS is dropped if the total of the PUSCH transmission power, the PUCCH transmission power and the SRS transmission power exceeds the maximum transmission power configured for the communication apparatus.