Method and apparatus for transmitting channel state information

A user equipment (UE), comprising:

• a radio frequency (RF) unit configured to transmit and receive radio signals;
• and
• a processor connected to the RF unit,
• wherein the processor is configured to:
• report first channel information to a base station periodically, and
• report second channel information to the base station periodically,
• wherein the first channel information and the second channel information are pieces of information combined to indicate one precoding matrix,
• wherein second channel information reported in a specific subframe is calculated based on last reported first channel information, and
• wherein a channel quality indicator (CQI) reported in the specific subframe is calculated based on one precoding matrix indicated by the last reported first channel information and the second channel information reported in the specific subframe.