Radio communication device and radio communication method configured for channel quality reporting of selected sub-carrier bands

1. A wireless communication apparatus comprising:

a radio receiver configured to acquire, from a base station, a first information indicating a fixed number identifying quantity of sub-carrier bands to be selected for channel quality reporting;

a reception quality measurer coupled to the radio receiver and configured to measure channel quality of each of a plurality of sub-carrier bands within a communication band from a received signal;

a subcarrier selector coupled to the radio receiver and configured to select sub-carrier bands from the plurality of sub-carrier bands based on the measured channel quality, wherein quantity of the selected sub-carrier bands matches the quantity of sub-carrier bands identified by the fixed number indicated by the first acquired information;

a modulator configured to modulate a second information indicating channel quality of the selected sub-carrier bands according to a modulation scheme and a third information indicating positions of the selected sub-carrier bands according to the modulation scheme; and

a radio transmitter configured to report to the base station the second and third modulated information.

2. The wireless communication apparatus according to claim 1 , wherein the subcarrier selector is configured to select the indicated fixed number of sub-carrier bands in descending order of the measured channel quality.

3. The wireless communication apparatus according to claim 1 , wherein the radio transmitter is further configured to spread the second information indicating channel quality of the selected sub-carrier bands using a spreading code specific to each user, and report the spread second information.

4. The wireless communication apparatus according to claim 1 , wherein the radio transmitter is further configured to spread the third information indicating positions of the selected sub-carrier bands using a spreading code specific to each user, and report the spread third information.

5. The wireless communication apparatus according to claim 1 , wherein the second information indicating channel quality of the selected sub-carrier bands is channel quality information (CQI).

6. The wireless communication apparatus according to claim 5 , wherein the CQI is generated based on comparison between a channel quality measurement value and predetermined regions of channel quality measurement values respectively indicating different CQIs.

7. The wireless communication apparatus according to claim 1 , wherein the second information indicates an aggregation of the channel quality of each of the selected sub-carrier bands.

8. The wireless communication apparatus according to claim 1 , wherein the radio transmitter is further configured to multiplex the second and third modulated information with an Acknowledgement/Negative Acknowledgement (ACK/NACK) signal for reporting to the base station.

9. A wireless communication method comprising:

acquiring, from a base station, a first information indicating a fixed number identifying quantity of sub-carrier bands to be selected for channel quality reporting;

measuring channel quality of each of a plurality of sub-carrier bands within a communication band from a received signal;

selecting sub-carrier bands from the plurality of sub-carrier bands based on the measured channel quality, wherein quantity of the selected sub-carrier bands matches the quantity of sub-carrier bands identified by the fixed number indicated by the first acquired information;

modulating a second information indicating channel quality of the selected sub-carrier bands according to a modulation scheme and a third information indicating positions of the selected sub-carrier bands according to the modulation scheme; and

reporting to the base station the second and third modulated information.

10. The wireless communication method according to claim 9 , wherein the selecting selects the indicated fixed number of sub-carrier bands in descending order of the measured channel quality.

11. The wireless communication method according to claim 9 , further comprising spreading the second information indicating channel quality of the selected sub-carrier bands using a spreading code specific to each user, wherein the reporting includes reporting of the spread second information.

12. The wireless communication method according to claim 9 , further comprising spreading the third information indicating positions of the selected sub-carrier bands using a spreading code specific to each user, wherein the reporting includes reporting of the spread third information.

13. The wireless communication method according to claim 9 , wherein the second information indicating channel quality of the selected sub-carrier bands is channel quality information (CQI).

14. The wireless communication method according to claim 13 , wherein the CQI is generated based on comparison between a channel quality measurement value and predetermined regions of channel quality measurement values respectively indicating different CQIs.

15. The wireless communication method according to claim 9 , wherein the second information indicates an aggregation of the channel quality of each of the selected sub-carrier bands.

16. The wireless communication method according to claim 9 , further comprising multiplexing the second and third modulated information with an Acknowledgement/Negative Acknowledgement (ACK/NACK) signal before reporting to the base station.