Method and apparatus for performing measurement in an extension carrier

A base station configuring a measurement for a mobile terminal configured with a plurality of component carriers in a wireless communication system, the base station comprising:

• a radio-frequency (RF) module;
• a processor;
• and
• a memory operably connectable to the processor and storing instructions that, when executed, cause the processor to perform operations comprising:
• transmitting configuration information to the mobile terminal;
• and
• wherein when the transmitted configuration information includes an indication information for the measurement in an extension component carrier among the plurality of component carriers, the measurement in the extension component carrier is based on based on a channel state information reference signal (CSI-RS), and
• wherein when the transmitted configuration information does not include the indication information for the measurement in the extension component carrier among the plurality of component carriers, the measurement in the extension component carrier is based on a cell specific reference signal (CRS).