COMMUNICATION TERMINAL, BASE STATION, WIRELESS COMMUNICATION SYSTEM, CONTROL METHOD AND PROGRAM THEREFOR, AND RECORDING MEDIUM HAVING CONTROL PROGRAM RECORDED THEREON

• US 20130208615A1
• Filed: 12/02/2011
• Published: 08/15/2013
• Est. Priority Date: 12/03/2010
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ishikura, Katsutoshi, Tsunekawa, Koichi, Kameno, Toshiaki, Konno, Yoshio, Ohsima, Akira
• Granted Patent: US 9,215,698 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

According to a control method of a wireless communication system in which wireless communication between a base station (12) and a communication terminal (11) is carried out by use of a plurality of discontinuous frequency bands, in a case where an onlyUL-CC having no existing corresponding DL-CC is present (S21), a communication quality of a DL-CC in a frequency band including the onlyUL-CC is measured as a communication quality of a DL-CC corresponding to the onlyUL-CC (S22) for the purpose of accurate control of the onlyUL-CC.

Claims

1. A wireless communication system in which wireless communication between a base station and a communication terminal is carried out by use of a plurality of frequency bands, wherein:

the plurality of frequency bands each include (i) a downlink sub-band that is a frequency band for use in downlink transmission from the base station to the communication terminal and (ii) an uplink sub-band that is a frequency band for use in uplink transmission from the communication terminal to the base station;

the base station includes band allocation means that allocates, to the communication terminal, the downlink sub-band and the uplink sub-band in the plurality of frequency bands;

the communication terminal includes quality measurement means that measures a communication quality of the downlink sub-band that has been allocated by the band allocation means of the base station;

the base station includes communication control determination means that determines, in accordance with the communication quality of the downlink sub-band, communication control of the uplink sub-band that has been allocated by the band allocation means of the base station, the communication quality having been measured by the quality measurement means of the communication terminal, the uplink sub-band that has been allocated corresponding to the downlink sub-band that has been allocated;

the communication terminal includes communication control means that controls, in accordance with the communication control of the uplink sub-band that has been allocated, the uplink transmission in the uplink sub-band that has been allocated, the communication control having been determined by the communication control determination means of the base station; and

in a case where there exists a frequency band that includes (i) the uplink sub-band having been allocated to the communication terminal by the band allocation means of the base station but (ii) no downlink sub-band that has been allocated to the communication terminal by the band allocation means of the base station,

(a) the quality measurement means of the communication terminal further measures, as a communication quality of a monitor downlink sub-band, a communication quality of a downlink sub-band that has not been allocated in the frequency band of the case, and

(b) the communication control determination means of the base station determines, in accordance with the communication quality of the monitor downlink sub-band, communication control of an only-uplink sub-band that is the uplink sub-band that has been allocated in the frequency band of the case, the communication quality having been measured by the quality measurement means of the communication terminal.

2. The wireless communication system as set forth in claim 1, wherein the monitor downlink sub-band whose communication quality is measured by the quality measurement means of the communication terminal is determined by the band allocation means of the base station.

3. The wireless communication system as set forth in claim 1, wherein the communication control means of the communication terminal keeps physical layer synchronization of the monitor downlink sub-band.

4. The wireless communication system as set forth in claim 1, wherein:

the quality measurement means of the communication terminal further measures a communication quality of a downlink sub-band of another base station that is different from the base station; and

the communication control determination means of the base station determines whether or not to carry out a handover of the uplink sub-band corresponding to the downlink sub-band, based on a comparison between (a) the communication quality of the downlink sub-band of the base station and (b) the communication quality of the downlink sub-band of the another base station, the communication qualities having been measured by the quality measurement means of the communication terminal.

5. The wireless communication system as set forth in claim 4 wherein the quality measurement means of the communication terminal carries out the comparison.

6. The wireless communication system as set forth in claim 5, wherein the quality measurement means of the communication terminal notifies the base station of a result of the comparison concerning the downlink sub-band that has been allocated and a result of the comparison concerning the monitor downlink sub-band.

7. The wireless communication system as set forth in claim 4, wherein:

in the comparison, a value obtained by adding a predetermined threshold to a value of the communication quality of the downlink sub-band of the base station is compared with a value of the communication quality of the downlink sub-band of the another base station; and

the predetermined threshold is different for each of the downlink sub-band that has been allocated and the monitor downlink sub-band.

12. The wireless communication system as set forth in claim 1, wherein the band allocation means of the base station allocates, to the communication terminal, the uplink sub-band corresponding to the downlink sub-band, in the order from the downlink sub-band whose value of the communication quality is the largest, the communication quality having been measured by the quality measurement means of the communication terminal.

13. A base station utilized in a wireless communication system as set forth in claim 1.

14. A communication terminal utilized in a wireless communication system as set forth in claim 1.

15. A computer-readable storage medium in which a control program for causing a wireless communication system as set forth in claim 1 to operate, the control program causing a computer to function as each means of the wireless communication system.

8. A wireless communication system in which wireless communication between a base station and a -communication terminal is carried out by use of a plurality of frequency bands, wherein:

the plurality of frequency bands each include (i) a downlink sub-band that is a frequency band for use in downlink transmission from the base station to the communication terminal and (ii) an uplink sub-band that is a frequency band for use in uplink transmission from the communication terminal to the base station;

the base station includes band allocation means that allocates, to the communication terminal, the downlink sub-band and the uplink sub-band in the plurality of frequency bands;

the communication terminal includes quality measurement means that measures a communication quality of the downlink sub-band that has been allocated by the band allocation means of the base station;

the base station includes communication control determination means that determines, in accordance with the communication quality of the downlink sub-band, communication control of the uplink sub-band that has been allocated by the band allocation means of the base station, the communication quality having been measured by the quality measurement means of the communication terminal, the uplink sub-band that has been allocated corresponding to the downlink sub-band that has been allocated;

the communication terminal includes communication control means that controls, in accordance with the communication control of the uplink sub-band that has been allocated, the uplink transmission in the uplink sub-band that has been allocated, the communication control having been determined by the communication control determination means of the base station;

the base station includes quality measurement means that (i) measures a reception power in the uplink sub-band and (ii) obtains a communication quality of the uplink sub-band from the reception power thus measured; and

in a case where there exists a frequency band that includes (i) the uplink sub-band having been allocated to the communication terminal by the band allocation means of the base station but (ii) no downlink sub-band that has been allocated to the communication terminal by the band allocation means of the base station,

the communication control determination means of the base station determines, in accordance with the communication quality having been obtained by the quality measurement means, communication control of an only-uplink sub-band that is the uplink sub-band in the frequency band of the case.

9. The wireless communication system as set forth in claim 8, wherein:

the quality measurement means of the communication terminal further measures a communication quality of a downlink sub-band of another base station that is different from the base station; and

the communication control determination means of the base station determines whether or not to carry out a handover of the only-uplink sub-band, based on comparison between (a) a communication quality of the only-uplink sub-band of the base station and (b) the communication quality of the downlink sub-band of the another base station, the communication quality of the only-uplink sub-band having been measured by the quality measurement means of the base station, the communication quality of the downlink sub-band having been measured by the quality measurement means of the communication terminal.

10. The wireless communication system as set forth in claim 8, wherein:

the communication terminal further includes transmission power obtaining means that obtains a transmission power for the uplink sub-band; and

the quality measurement means of the base station obtains the communication quality of the only-uplink sub-band, from the reception power that the quality measurement means of the base station has measured and the transmission power that has been obtained by the transmission power obtaining means of the communication terminal.

11. A wireless communication system in which wireless communication between a base station and a communication terminal is carried out by use of a plurality of frequency bands, wherein:

the plurality of frequency bands each include (i) a downlink sub-band that is a frequency band for use in downlink transmission from the base station to the communication terminal and (ii) an uplink sub-band that is a frequency band for use in uplink transmission from the communication terminal to the base station;

the base station includes band allocation means that allocates, to the communication terminal, the downlink sub-band and the uplink sub-band in the plurality of frequency bands;

the communication terminal includes quality measurement means that measures a communication quality of the downlink sub-band that has been allocated by the band allocation means of the base station;

the base station includes communication control determination means that determines, in accordance with the communication quality of the downlink sub-band, communication control of the uplink sub-band that has been allocated by the band allocation means of the base station, the communication quality having been measured by the quality measurement means of the communication terminal, the uplink sub-band that has been allocated corresponding to the downlink sub-band that has been allocated;

the communication terminal includes communication control means that controls, in accordance with the communication control of the uplink sub-band that has been allocated, the uplink transmission in the uplink sub-band that has been allocated, the communication control having been determined by the communication control determination means of the base station; and

in a case where there exists a frequency band that includes (i) the uplink sub-band which the band allocation means of the base station is required to allocate to the communication terminal and (ii) the downlink sub-band which the band allocation means of the base station is not required to allocate to the communication terminal,

the band allocation means of the base station allocates, to the communication terminal, the downlink sub-band in the frequency band of the case as a downlink sub-band for measuring the communication quality.

16-19. -19. (canceled)