Base station apparatus and radio communication method for receiving information indicative of channel quality from mobile station

A communication method implemented by a base station, the method comprising:

• multiplexing (1) control information comprising first information indicating a fixed number identifying quantity of sub-carrier bands to be selected by a mobile station for channel quality reporting and (2) transmission data;
• transmitting the multiplexed information to the mobile station;
• receiving second information and third information from the mobile station;
• and
• obtaining, from the second information, channel quality of selected sub-carrier bands and obtaining, from the third information, positions of the selected sub-carrier bands, wherein the selected sub-carrier bands are selected by the mobile station and quantity of the selected sub-carrier bands matches the quantity of sub-carrier bands indicated by the first information.

A wireless communication apparatus comprising:

• a radio receiver configured to acquire, from a base station, multiplexed information comprising (1) control information comprising first information indicating a fixed number identifying quantity of sub-carrier bands to be selected by a mobile station for channel quality reporting;
• and (2) data information;
• a demultiplexer configured to demultiplex the multiplexed information and to provide demultiplexed control information and data information;
• 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 received signals;
• a subcarrier selector coupled to the radio receiver and configured to select subcarrier bands from the plurality of sub-carrier bands, wherein quantity of the selected subcarrier bands matches the quantity of sub-carrier bands identified by the fixed number obtained from the demultiplexed control 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 subcarrier bands according to the modulation scheme;
• and
• a radio transmitter configured to report to the base station the second and third modulated information.