Method for transmitting/receiving channel state information on basis of codebook having high resolution in wireless communication system, and apparatus therefor

A user equipment (UE) for reporting channel state information (CSI) in a wireless communication system, the UE comprising:

• a transceiver configured to transmit and receive a radio signal, and
• a processor functionally connected to the transceiver,
• wherein the processor is configured to:
• receive CSI reporting-related configuration information from a base station by controlling the transceiver,
• wherein a report for at least one of aperiodic CSI, periodic CSI, or semi-persistent CSI is configured based on the CSI reporting-related configuration information,
• calculate first information and second information for a channel quality, based on the CSI reporting-related configuration information,
• calculate the first information by applying a precoding matrix indicator (PMI) included in latest aperiodically reported CSI, and calculate the second information by applying the PMI at a time of calculation of the second information, and
• determine at least one of whether to transmit a flag and a value of the flag, based on the first information and the second information, and
• report the CSI to the base station based on the first information and the flag.