Communication Terminal Apparatus, Base Station Apparatus, and Resource Assigning Method
A communication terminal apparatus of wireless communication system wherein the data amount of report values is reduced and the accuracy of the report values is enhanced in OFDM wireless communication. In a communication terminal apparatus ( 200 ), a reception quality measuring part ( 206 ) measures, based on information outputted from a demodulating part ( 205 ), the reception quality for each subcarrier. A block size deciding part ( 207 ) determines a coherent bandwidth for which the reception quality of each subcarrier is below a predetermined threshold value. The block size deciding part ( 207 ) then decides the coherent bandwidth as the block size of the subcarriers. A report value generating part ( 208 ) groups a plurality of subcarriers into a subcarrier block for each block size decided by the block size deciding part ( 207 ), averages the reception qualities, measured by the reception quality measuring part ( 206 ), for each subcarrier block, and generates reception quality information indicative of the reception quality average of each subcarrier block.
1 . A communication terminal apparatus in a radio communication system where a plurality of communication terminal apparatuses and a base station apparatus perform radio communication of an orthogonal frequency division multiplexing scheme and where the base station apparatus performs scheduling based on a report value showing received quality at the communication terminal apparatuses in communication, the communication terminal apparatus comprising:
a received quality measuring section that measures received quality, per subcarrier, of a signal transmitted from the base station apparatus;
a block size determining section that decides a coherence bandwidth where the received quality of each subcarrier stays within a predetermined threshold and that determines the coherence bandwidth as a subcarrier block size;
a report value generating section that groups a plurality of subcarriers into a subcarrier block according to a block size decided by the block size determining section, finds an average of received quality per subcarrier block and generates received quality information showing the average received quality value per subcarrier block; and
a transmitting section that transmits the received quality information and information showing the block size to the base station apparatus.
2 . The communication terminal apparatus according to claim 1 , wherein the block size determining section finds an average of a plurality of coherence bandwidths and fixes the block size.
3 . The communication terminal apparatus according to claim 1 , further comprising a threshold setting section that sets a threshold used to decide a coherence bandwidth according to quality of service, wherein the block size determining section decides a coherence bandwidth where the received quality of each subcarrier stays within the threshold set by the threshold setting section.
4 . The communication terminal apparatus according to claim 3 , wherein the threshold setting section makes the threshold smaller for a service where required transmission speed is fast or the amount of allowed delay is small.
5 . A communication terminal apparatus in a radio communication system where a plurality of communication terminal apparatuses and a base station apparatus perform a radio communication of an orthogonal frequency division multiplexing scheme and the base station apparatus performs scheduling based on a report value showing the received quality of the communication terminal apparatuses in communication, the communication terminal apparatus comprising:
a demodulating section that demodulates information showing the block size determined by the communication terminal apparatuses and received quality information showing the average of received quality of subcarrier block according to the block size; and
a scheduling section that performs a resource allocation based on the received quality information of each subcarrier block according to the block size.
6 . A resource allocation method in which a plurality of communication terminal apparatuses and a base station apparatus perform radio communication of orthogonal frequency division multiplexing scheme and where the base station apparatus performs scheduling based on a report value showing received quality of the communication terminal apparatuses in communication, wherein:
the communication terminal apparatuses decide a coherence bandwidth where the received quality of each subcarrier stays within a predetermined threshold as a subcarrier block size;
the communication terminal apparatus groups a plurality of subcarriers into a subcarrier block per the block size, finds an average of received quality per subcarrier block and generates received quality information showing the average received quality value per subcarrier block;
the communication terminal apparatus transmits the received quality information and information showing the block size;
the base station apparatus demodulates the received quality information and information showing the block size; and
the base station apparatus performs a resource allocation based on the received quality information per subcarrier block according to the block size.