Method and apparatus for reporting channel state information in wireless communication system

A method for receiving channel state information (CSI) by a base station in a wireless communication system, comprising:

• transmitting a channel state information reference signal (CSI-RS) to a terminal through a multi-antenna port;
• and
• receiving CSI from the terminal,
• wherein the CSI includes a precoding matrix indicator for a codebook generated by linear combination,
• wherein the codebook is generated based on a specific parameter set, and
• wherein the specific parameter set is differently set/applied based on a rank value.

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

• RF (Radio Frequency) module for transmitting and receiving a radio signal;
• and
• a processor for controlling the RF module, wherein the processor,
• receiving a channel state information reference signal (CSI-RS) from a base station through a multiple antenna port;
• and
• reporting the CSI to the base station,
• wherein the CSI includes a precoding matrix indicator for a codebook generated by linear combination,
• wherein the codebook is generated based on a specific parameter set, and
• wherein the specific parameter set is differently set/applied based on a rank value.