Method and apparatus for reporting a channel quality in a wireless communication system

Abstract

The present invention provided a method and apparatus for reporting a channel quality in a wireless communication system. A terminal receives an uplink grant from a base station via one of a plurality of downlink component carriers (CCs). The uplink grant includes a channel quality indicator (CQI) request for instructing uplink allocation and CQI reporting. The terminal reports the CQI of the downlink CC being linked to the base station. The downlink CC being linked is one of the plurality of downlink CCs, which is linked to the uplink CC for which the uplink allocation is scheduled.

The invention claimed is: 
     
       1. A method for reporting channel quality by a device in a wireless communication system, the method comprising:
 receiving, by the device, an uplink grant on a physical downlink control channel (PDCCH) through one of a plurality of downlink component carriers (CCs), the uplink grant including an uplink allocation and a channel quality indicator (CQI) request indicating a triggering of CQI reporting,   wherein, when a value of the CQI request is set to a first value, the CQI request indicates the triggering of CQI reporting is for one of the plurality of downlink CCs linked to an uplink CC, when the value of the CQI request is set to a second value, the CQI request indicates the triggering of CQI reporting is for a first set of downlink CCs of the plurality of downlink CCs, and when the value of the CQI request is set to a third value, the CQI request indicates the triggering of CQI reporting is for a second set of downlink CCs of the plurality of downlink CCs; and   reporting, by the device, a CQI for a downlink CC indicated by the CQI request through an uplink CC based on the uplink allocation.   
     
     
       2. The method of  claim 1 , wherein the uplink grant further includes a carrier indicator field (CIF) indicating the uplink CC in which the uplink allocation is scheduled. 
     
     
       3. The method of  claim 1 , wherein a number of bits for the CQI request is two. 
     
     
       4. The method of  claim 1 , further comprising:
 receiving information on the first set of downlink CCs and the second set of downlink CCs.   
     
     
       5. The method of  claim 1 , wherein a linkage between the one of the plurality of downlink CCs linked to the uplink CC is received via system information. 
     
     
       6. The method of  claim 1 , wherein the first value is “1,” the second value is “2,” and the third value is “3.” 
     
     
       7. An apparatus configured for reporting channel quality in a wireless communication system, the apparatus comprising:
 a radio frequency (RF) unit configured to transmit and receive a radio signal; and   a processor coupled to the RF unit and configured to:
 receive an uplink grant on a physical downlink control channel (PDCCH) through one of a plurality of downlink component carriers (CCs), the uplink grant including an uplink allocation and a channel quality indicator (CQI) request indicating a triggering of CQI reporting; wherein, when a value of the CQI request is set to a first value, the CQI request indicates the triggering of CQI reporting is for one of the plurality of downlink CCs linked to an uplink CC, when the value of the CQI request is set to a second value, the CQI request indicates the triggering of CQI reporting is for a first set of downlink CCs of the plurality of downlink CCs, and when the value of the CQI request is set to a third value, the CQI request indicates the triggering of CQI reporting is for a second set of downlink CCs of the plurality of downlink CCs; and 
 report a CQI for a downlink CC indicated by the CQI request through an uplink CC based on the uplink allocation. 
   
     
     
       8. The apparatus of  claim 7 , wherein the uplink grant further includes a carrier indicator field (CIF) indicating the uplink CC in which the uplink allocation is scheduled. 
     
     
       9. The apparatus of  claim 7 , wherein a number of bits for the CQI request is two. 
     
     
       10. The apparatus of  claim 7 , wherein the processor is configured to receive information on the first set of downlink CCs and the second set of downlink CCs. 
     
     
       11. The apparatus of  claim 7 , wherein a linkage between the one of the plurality of downlink CCs linked to the uplink CC is received via system information. 
     
     
       12. The apparatus of  claim 7 , wherein the first value is “1,” the second value is “2,” and the third value is “3.” 
     
     
       13. A method for reporting a channel quality indicator (CQI) via a physical uplink shared channel (PUSCH) in a wireless communication system, the method comprising:
 receiving, by a terminal configured with a plurality of downlink component carriers (CCs), control information via a physical downlink control channel (PDCCH) from a base station, wherein the control information includes a CQI request, an uplink allocation and a carrier indicator (CI); and   transmitting, by the terminal to the base station, a CQI report via the PUSCH of an uplink CC, based on the uplink allocation, wherein:
 the uplink CC is indicated by the CI; 
 the CQI request indicates one of:
 a triggering of CQI reporting for one downlink CC linked to the uplink CC, indicated by the CI, among the plurality of downlink CCs; or 
 a triggering of CQI reporting for a first group of downlink CCs among the plurality of downlink CCs; 
 
 the CQI report based on the CQI request corresponds to an aperiodic CQI; and 
 when the CQI request indicates the triggering of the aperiodic CQI reporting for one downlink CC, the downlink CC is identified by a linkage with the uplink CC indicated by the CI. 
   
     
     
       14. The method of claim 13, wherein:
 if a value related to the CQI request is set to a first value, the CQI request indicates the triggering of CQI reporting for the one downlink CC; and   if the value related to the CQI request is set to a second value, the CQI request indicates the triggering of CQI reporting for the first group of downlink CCs among the plurality of downlink CCs.   
     
     
       15. The method of claim 14, wherein, if the value related to the CQI request is set to a third value, the CQI request indicates a triggering of CQI reporting for a second group of downlink CCs among the plurality of downlink CCs. 
     
     
       16. The method of claim 13, further comprising receiving information on the first group of downlink CCs and a second group of downlink CCs from the base station. 
     
     
       17. The method of claim 13, wherein a number of bits for the CQI request is two. 
     
     
       18. A user equipment (UE) for reporting a channel quality indicator (CQI) via a physical uplink shared channel (PUSCH) in a wireless communication system, the UE comprising:
 a transceiver configured with a plurality of downlink component carriers (CCs); and   a processor configured to control the transceiver thereby performing:
 receiving control information via a physical downlink control channel (PDCCH) from a base station, the control information including a CQI request, an uplink allocation and a carrier indicator (CI); and 
 transmitting, to the base station, a CQI report via the PUSCH of an uplink CC, based on the uplink allocation, wherein:
 the uplink CC is indicated by the CI; 
 the CQI request indicates one of:
 a triggering of CQI reporting for one downlink CC linked to the uplink CC, indicated by the CI, among the plurality of downlink CCs; and 
 a triggering of CQI reporting for a first group of downlink CCs among the plurality of downlink CCs; 
 
 the CQI report based on the CQI request corresponds to an aperiodic CQI; and 
 when the CQI request indicates the triggering of the aperiodic CQI reporting for one downlink CC, the downlink CC is identified by a linkage with the uplink CC indicated by the CI. 
 
   
     
     
       19. The UE of claim 20, wherein:
 if a value related to the CQI request is set to a first value, the CQI request indicates the triggering of CQI reporting for the one downlink CC; and   if the value related to the CQI request is set to a second value, the CQI request indicates the triggering of CQI reporting for the first group of downlink CCs among the plurality of downlink CCs.   
     
     
       20. The UE of claim 19, wherein, if the value related to the CQI request is set to a third value, the CQI request indicates a triggering of CQI reporting for a second group of downlink CCs among the plurality of downlink CCs. 
     
     
       21. The UE of claim 18, wherein the processor is further configured to receive information on the first group of downlink CCs and a second group of downlink CCs from the base station. 
     
     
       22. The UE of claim 18, wherein a number of bits for the CQI request is two.