Base station apparatus, communication terminal apparatus, and communication method

Abstract

An assignment section 101 determines communication resource assignment to communication terminals based on a transmission rate at which communication is possible for each subcarrier of each communication terminal, and instructs a buffer section 102 to output forward transmission data. In addition, the assignment section 101 instructs a frame creation section 103 to perform forward transmission data symbolization, and also outputs a signal indicating communication resource assignment to each communication terminal. The buffer section 102 holds forward transmission data, and outputs forward transmission data to the frame creation section 103 in accordance with instructions from the assignment section 101 . The frame creation section 103 symbolizes a resource assignment signal and transmission data to create a frame, which it outputs to a spreading section 104.

1. A base station apparatus comprising:
 a receiver that receives a signal representing communication quality estimated per subcarrier in a communication terminal apparatus of a communicating party; 
 an assigner that assigns subcarriers for use in communication with the communication terminal apparatus in accordance with the signal representing communication quality; and 
 a transmitter that transmits data to the communication terminal apparatus using the subcarriers assigned by the assigner. 
 
     
     
       2. The base station apparatus of  claim 1  wherein the transmitter transmits subcarrier assignment information per subcarrier. 
     
     
       3. The base station apparatus of  claim 1 , wherein the assigner assigns the subcarriers, for use in communication with the communication terminal apparatus, per time slot. 
     
     
       4. The base station apparatus of  claim 1 , wherein the assigner determines a spreading factor, of the data transmitted from the transmitter, in accordance with the signal representing communication quality. 
     
     
       5. A communication terminal apparatus comprising a demodulator that demodulates a signal, addressed to said communication terminal apparatus and carried by subcarriers, in accordance with the subcarrier assignment information transmitted from the base station apparatus of  claim 2 . 
     
     
       6. The communication terminal apparatus of  claim 5 , wherein the demodulator performs threshold determination of quality of the signal addressed to said communication terminal apparatus and demodulates said signal when the quality is above a predetermined threshold. 
     
     
       7. A communication method comprising:
 receiving a signal at a base station apparatus, said signal representing communication quality estimated per subcarrier in a communication terminal apparatus of a communicating party; 
 assigning subcarriers for use in communication with the communication terminal apparatus in accordance with the signal representing communication quality; 
 transmitting subcarrier assignment information and data to the communication terminal apparatus using the assigned subcarriers; and 
 demodulating a signal addressed to the communication terminal apparatus and carried by the subcarriers, in accordance with the subcarrier assignment information transmitted from the base station apparatus. 
 
     
     
       8. A communication method comprising:
 receiving a signal at a base station apparatus, said signal representing communication quality estimated per subcarrier in a communication terminal apparatus of a communicating party; 
 assigning subcarriers for use in communication with the communication terminal apparatus in accordance with the signal representing communication quality; 
 transmitting data to the communication terminal apparatus using the assigned subcarriers; and 
 performing threshold determination of quality of a signal addressed to the communication terminal apparatus and demodulating said signal when the quality is above a predetermined threshold. 
 
     
     
       9. A base station apparatus comprising:
 a receiver that receives a signal representing communication quality, which is estimated per band in a communication terminal apparatus of a communicating party, wherein a frequency domain comprised of subcarriers is divided into bands, each of the bands being comprised of a subcarrier;   an assigner that assigns subcarriers for use in communication with the communication terminal apparatus in accordance with the signal representing communication quality; and   a transmitter that transmits data to the communication terminal apparatus using the subcarriers assigned by the assigner.   
     
     
       10. The base station apparatus of claim 9 wherein the transmitter transmits subcarrier assignment information per the subcarriers assigned to the communication terminal apparatus. 
     
     
       11. The base station apparatus of claim 9, wherein the assigner assigns the subcarriers, for use in communication with the communication terminal apparatus, per time slot. 
     
     
       12. A communication terminal apparatus comprising a demodulator that demodulates a signal addressed to said communication terminal apparatus and carried by the subcarriers, in accordance with the subcarrier assignment information transmitted from the base station apparatus of claim 10. 
     
     
       13. A communication terminal apparatus comprising:
 a transmitter that transmits a signal representing communication quality estimated per band to a base station apparatus, wherein a frequency domain comprised of subcarriers is divided into bands, each of the bands being comprised of a subcarrier; and   a receiver that receives subcarrier assignment information transmitted from the base station apparatus, and receives data, which is transmitted from the base station apparatus using subcarriers assigned to said communication terminal apparatus in accordance with the signal representing communication quality, based on the subcarrier assignment information.   
     
     
       14. A communication method comprising:
 receiving a signal at a base station apparatus, said signal representing communication quality estimated per band in a communication terminal apparatus of a communicating party, wherein a frequency domain comprised of subcarriers is divided into bands, each of the bands being comprised of a subcarrier;   assigning subcarriers for use in communication with the communication terminal apparatus in accordance with the signal representing communication quality;   transmitting subcarrier assignment information; and   transmitting data to the communication terminal apparatus using the assigned subcarriers.   
     
     
       15. A base station apparatus communicating with a terminal apparatus, said base station apparatus comprising:
 a receiver that receives a signal transmitted from said terminal apparatus, the signal indicating communication quality calculated in said terminal apparatus for each of bands, into which a frequency domain comprised of subcarriers is divided, and each of the bands comprises a subcarrier;   an assigner that assigns, to said terminal apparatus, a resource comprised of consecutive subcarriers in a part of the bands; and   a transmitter that transmits data to the terminal apparatus using the resource.   
     
     
       16. The base station apparatus according to claim 15, wherein said base station communicates with a plurality of terminal apparatuses, and said receiver receives the signal transmitted from each of the terminal apparatuses and said assigner assigns the resource to each of the terminal apparatuses. 
     
     
       17. The base station apparatus according to claim 15, wherein the signal indicates a transmission rate of the data as the communication quality. 
     
     
       18. The base station apparatus according to claim 15, wherein said transmitter transmits assignment information indicating the resource assigned to said terminal apparatus. 
     
     
       19. The base station apparatus according to claim 15, wherein said transmitter transmits data with a transmission rate set per the resource assigned to said terminal apparatus. 
     
     
       20. The base station apparatus according to claim 15, wherein the signal indicating communication quality includes information related to transmission rate. 
     
     
       21. A terminal apparatus communicating with said base station apparatus according to claim 15, said terminal apparatus comprising:
 a transmitter that transmits the signal indicating communication quality calculated for each of the bands to said base station apparatus; and   a receiver that receives the data, which is transmitted from said base station apparatus using the resource assigned to said terminal apparatus.   
     
     
       22. A terminal apparatus communicating with said base station apparatus according to claim 18, said terminal apparatus comprising:
 a transmitter that transmits the signal indicating communication quality calculated for each of the bands to said base station apparatus; and   a receiver that receives the assignment information transmitted from said base station apparatus, and receives the data, which is transmitted from said base station apparatus using the resource assigned to said terminal apparatus, in accordance with the assignment information.   
     
     
       23. A terminal apparatus communicating with a base station apparatus, said terminal apparatus comprising:
 a transmitter that transmits, to said base station apparatus, a signal indicating communication quality calculated for each of bands, into which a frequency domain comprised of subcarriers is divided, and each of the bands comprises a subcarrier; and   a receiver that receives data, which is transmitted from said base station apparatus using a resource, which is comprised of consecutive subcarriers in a part of the bands and which said base station assigns to said terminal apparatus.   
     
     
       24. The terminal apparatus according to claim 23, wherein said receiver receives assignment information, which indicates the resource assigned to said terminal apparatus and which is transmitted from said base station apparatus, and said receiver receives the data in accordance with the assignment information.