Method for transmitting and receiving channel state information in wireless communication system and apparatus therefor

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

• a radio frequency (RF) unit;
• and
• a processor configured to control the RF unit,
• wherein the processor is further configured to
• receive, from a base station, a Channel State Information Reference Signal (CSI-RS) through multiple antenna ports, and
• report, to the base station, CSI,
• wherein the CSI includes selection information related to a plurality of beams used for generating a precoding matrix in a codebook for reporting the CSI, and a power coefficient, a phase offset, and a phase change value,
• wherein the power coefficient, the phase offset, and the phase change value are applied to each of the plurality of beams based on an index related to subbands within a configured bandwidth,
• wherein the phase offset is related to a phase shift keying,
• wherein the phase change value is determined based on (i) an index related to subbands within a configured bandwidth and (ii) a specific coefficient representing a change rate of a phase shift with respect to the index, and
• wherein each of the precoding matrix of the subbands included in the configured bandwidth is generated based on a linear combination of the plurality of beams to which the power coefficient, the phase offset, and the phase change value are applied.