Methods and apparatus are provided in which a configuration message to configure at least one uplink carrier is received. A power headroom report (PHR) is triggered for a first uplink carrier if a predetermined event occurs. An allocation of an uplink transmission resource is detected for the PHR. It is identified whether the first uplink carrier for which a power headroom (PH) is to be determined is different from a second carrier to which the uplink transmission resource is allocated. The PH is determined based on a first pathloss associated with the first uplink carrier, if the first uplink carrier is different from the second carrier. The PHR generated based the determined PH is transmitted.