Method for transmitting effective channel status information in wireless communication system supporting multiple carriers

1. A method for indicating channel status information (CSI) transmission in a wireless communication system supporting multiple carriers, the method comprising: transmitting downlink control information (DCI) including a CSI request field to a user equipment (UE) over a physical downlink control channel (PDCCH), the CSI request field having a length of 2 bits; and receiving CSI reporting of a single downlink carrier or CSI reporting of multiple downlink carriers from the UE over a physical uplink shared channel (PUSCH) without receiving uplink data, wherein, when the CSI request field has a value of ‘01’, a number (NPRB) of resource blocks (RBs) established for the CSI reporting is identical to or less than X (NPRB≦X), and wherein, when the CSI request field has a value ‘10’ or ‘11’, the NPRB established for the CSI reporting is identical to or less than M (where M>X), wherein the CSI request field value of ‘01’ further indicates that the CSI reporting is CSI reporting for a single downlink carrier, and the CSI request field value of ‘10’ or ‘11’ further indicates that the CSI reporting is CSI reporting for multiple downlink carriers, and wherein only a QPSK (Quadrature Phase Shift Keying) modulation scheme is applied to the CSI reporting for the single downlink carrier and the CSI reporting for the multiple downlink carriers.

2. The method according to claim 1 , wherein the CSI request field is assigned a specific value indicating aperiodic CSI reporting.

3. The method according to claim 1 , wherein the DCI further includes a modulation and coding scheme (MCS) index (I MCS ), where I MCS is set to 29.

4. The method according to claim 3 , wherein the I MCS value indicates a value regarding an enabled transport block (TB).

5. The method according to claim 1 , wherein the X value is set to 4.

6. The method according to claim 1 , wherein the CSI includes at least one of a channel quality indicator (CQI), a precoding matrix index (PMI), and a rank indicator (RI).

7. A method for indicating channel status information (CSI) transmission in a wireless communication system supporting multiple carriers, the method comprising: receiving downlink control information (DCI) including a CSI request field from a base station (BS) over a physical downlink control channel (PDCCH), the CSI request field having a length of 2 bits; and transmitting CSI reporting of a single downlink carrier or CSI reporting of multiple downlink carriers to the BS over a physical uplink shared channel (PUSCH) without transmitting uplink data, wherein, when the CSI request field has a value of ‘01’, a number (NPRB) of resource blocks (RBs) established for the CSI reporting is identical to or less than X (NPRB≦X), and wherein, when the CSI request field has a value ‘10’ or ‘11’, the NPRB established for the CSI reporting is identical to or less than M (where M>X), wherein the CSI request field value of ‘01’ further indicates that the CSI reporting is CSI reporting for a single downlink carrier, and the CSI request field value of ‘10’ or ‘11’ further indicates that the CSI reporting is CSI reporting for multiple downlink carriers, and wherein only a QPSK (Quadrature Phase Shift Keying) modulation scheme is applied to the CSI reporting for the single downlink carrier and the CSI reporting for the multiple downlink carriers.

8. The method according to claim 7 , wherein the CSI request field is assigned a specific value indicating aperiodic CSI reporting.

9. The method according to claim 7 , wherein the DCI further includes a modulation and coding scheme (MCS) index (I MCS ), where I MCS is set to 29.

10. The method according to claim 9 , wherein the I MCS value indicates a value regarding an enabled transport block (TB).

11. The method according to claim 7 , wherein the X value is set to 4.

12. The method according to claim 7 , wherein the CSI includes at least one of a channel quality indicator (CQI), a precoding matrix index (PMI), and a rank indicator (RI).

13. A base station (BS) for indicating channel status information (CSI) transmission in a wireless communication system supporting multiple carriers comprising: a receiver configured to receive an uplink signal from a user equipment (UE); a transmitter configured to transmit a downlink signal to the UE; and a processor operatively connected to the transmitter and the receiver, the processor configured to transmit, through the transmitter, downlink control information (DCI) including a CSI request field to the UE over a physical downlink control channel (PDCCH), the CSI request field having a length of 2 bits, and receive, through the receiver, CSI reporting of a single downlink carrier or CSI reporting of multiple downlink carriers from the UE over a physical uplink shared channel (PUSCH) without receiving uplink data, wherein, when the CSI request field has a value of ‘01’, a number (NPRB) of resource blocks (RBs) established for the CSI reporting is identical to or less than X (NPRB≦X), and wherein, when the CSI request field has a value ‘10’ or ‘11’, the NPRB established for the CSI reporting is identical to or less than M (where M>X), wherein the CSI request field value of ‘01’ further indicates that the CSI reporting is CSI reporting for a single downlink carrier, and the CSI request field value of ‘10’ or ‘11’ further indicates that the CSI reporting is CSI reporting for multiple downlink carriers, and wherein only a QPSK (Quadrature Phase Shift Keying) modulation scheme is applied to the CSI reporting for the single downlink carrier and the CSI reporting for the multiple downlink carriers.

14. A user equipment (UE) for transmitting channel status information (CSI) in a wireless communication system supporting multiple carriers comprising: a receiver for receiving a downlink signal from a base station (BS); a transmitter for transmitting an uplink signal to the BS; and a processor operatively connected to the transmitter and the receiver, the processor configured to receive, through the receiver, downlink control information (DCI) including a CSI request field from the BS over a physical downlink control channel (PDCCH), and transmit, through the transmitter, CSI reporting of a single downlink carrier or CSI reporting of multiple downlink carriers to the BS over a physical uplink shared channel (PUSCH) without transmitting uplink data, wherein, when the CSI request field has a value of ‘01’, a number (NPRB) of resource blocks (RBs) established for the CSI reporting is identical to or less than X (NPRB≦X), and wherein, when the CSI request field has a value ‘10’ or ‘11’, the NPRB established for the CSI reporting is identical to or less than M (where M>X), wherein the CSI request field value of ‘01’ further indicates that the CSI reporting is CSI reporting for a single downlink carrier, and the CSI request field value of ‘10’ or ‘11’ further indicates that the CSI reporting is CSI reporting for multiple downlink carriers, and wherein only a QPSK (Quadrature Phase Shift Keying) modulation scheme is applied to the CSI reporting for the single downlink carrier and the CSI reporting for the multiple downlink carriers.