Method and apparatus for performing effective feedback in wireless communication system supporting multiple antennas

A method for reporting channel status information (CSI) in a wireless access system supporting multicarrier aggregation, the method performed by a user equipment (UE) and comprising:

• calculating first CSI for a first component carrier (CC) of the multiple CCs based on a first CSI report type;
• calculating second CSI for a second CC of the multiple CCs based on a second CSI report type;
• and
• reporting only the first CSI through a physical uplink control channel (PUCCH), when a collision of a report of the first CSI with a report of the second CSI is occurred at a same subframe,
• wherein a content of the first CSI or the second CSI includes at least a rank indicator (RI), a wideband (WB) precoding matrix indicator (PMI), a WB first PMI, a WB second PMI, a subband (SB) second PMI, a precoder type indication (PTI), a WB channel quality indicator (CQI), or a SB CQI,
• wherein the first CSI report type is included in a report type group A or a report type group B, and the second CSI report type is included in a report type group C or a report type group D,
• wherein the report type group A and the report type group B have a same priority, and
• wherein the report type group C and the report type group D have a lower priority than the report type group A and the report type group B.

A user equipment (UE) for reporting channel status information (CSI) in a wireless access system supporting multicarrier aggregation, the UE comprising:

• a transmitter;
• and
• a processor,
• wherein the processor calculates first CSI for a first component carrier (CC) of the multiple CCs based on a first CSI report type and calculates second CSI for a second CC of the multiple CCs based on a second CSI report type,
• wherein the processor controls the transmitter to report only the first CSI through a physical uplink control channel (PUCCH), when a collision of a report of the first CSI with a report of the second CSI is occurred at a same subframe,
• wherein a content of the first CSI or the second CSI includes at least a rank indicator (RI), a wideband (WB) precoding matrix indicator (PMI), a WB first PMI, a WB second PMI, a subband (SB) second PMI, a precoder type indication (PTI), a WB channel quality indicator (CQI), or a SB CQI,
• wherein the first CSI report type is included in a report type group A or a report type group B, and the second CSI report type is included in a report type group C or a report type group D,
• wherein the report type group A and the report type group B have a same priority, and
• wherein the report type group C and the report type group D have a lower priority than the report type group A and the report type group B.