Uplink control channel transmission control method in a multi-carrier system and terminal using same

A mobile station in a multi-carrier system in which a plurality of downlink Component Carriers (DL CCs) and at least one uplink component carrier (UL CC) are configured for the mobile station, the mobile station comprising:

• a Radio Frequency (RF) unit configured to transmit and receive radio signals;
• and
• a processor configured to:
• receive configuration information indicating a sign or value of each of Transmission Power Command (TPC) fields included in a plurality of DL grants, respectively, from a base station,
• receive the plurality of DL grants from the base station,
• test the Transmission Power Command (TPC) fields included in the plurality of DL grants, respectively, wherein the testing of the TPC fields is performed by validating information in the TPC fields,
• determine the transmission power of the uplink control channel (PUCCH) using a value of a TPC field through which the test has passed, and
• transmit the uplink control channel using the determined transmission power through one configured UL CC among the at least one UL CC,
• wherein the TPC fields included in the plurality of DL grants, respectively, are configured to have an identical sign or a ‘0’ value,
• wherein the sign indicates a positive value or negative value, and
• wherein the transmission power of the uplink control channel is determined by adding only values of TPC fields each having a sign identical with a sign indicated by the configuration information, from among the TPC fields included in the plurality of DL grants, respectively.