WIRELESS COMMUNICATION SYSTEM, COMMUNICATION CONTROL APPARATUS, COMMUNICATION TERMINAL APPARATUS, AND CONTROL PROGRAM OF COMMUNICATION CONTROL APPARATUS

• US 20120218961A1
• Filed: 08/20/2010
• Published: 08/30/2012
• Est. Priority Date: 09/18/2009
• 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: Goto, Jungo, Hamaguchi, Yasuhiro, Yokomakura, Kazunari, Nakamura, Osamu, Takahashi, Hiroki
• Granted Patent: US 9,301,260 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/247 where the output power of a terminal is based on a path parameter sent by another terminal
• CPC Class Codes: H04W 52/26 using transmission rate or quality of service QoS [Quality of Service]
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA

Abstract

To perform control so as to achieve a transmission power that satisfies a desired communication quality by an access method which a mobile station apparatus uses, in consideration of the frequency-selective diversity effect, when switching an access method to the one having a different frequency-selective diversity effect. In a wireless communication system in which a communication control apparatus and a communication terminal apparatus that are able to use a plurality of types of access methods perform wireless communication using any of the access methods, the communication control apparatus, when the necessity of changing the access method arises, determines the access method after change and notifies the communication terminal apparatus of switching the access method before change to the determined access method, and performs the transmission power control in accordance with communication characteristics of the determined access method.

Claims

1. A wireless communication system in which a communication control apparatus and a communication terminal apparatus that are able to use a plurality of types of access methods perform wireless communication using any of the access methods, wherein

said communication control apparatus, when the necessity of changing the access method arises, determines the access method after change and notifies said communication terminal apparatus of switching the access method before change to said determined access method, and

performs transmission power control in accordance with communication characteristics of said determined access method.

2. The wireless communication system according to claim 1, wherein

said plurality of types of access methods includes a first access method that allocates frequency domain signals to contiguous frequency bands, and a second access method that allocates frequency domain signals to discrete frequency bands, and wherein

said communication control apparatus, in said second access method, changes a control amount of the transmission power by a control signal notified of to said communication terminal apparatus in accordance with a frequency bandwidth allocated discretely.

3. The wireless communication system according to claim 1, wherein

said plurality of types of access methods includes a first access method that allocates frequency domain signals to contiguous frequency bands, and a second access method that allocates frequency domain signals to discrete frequency bands, and wherein

said communication terminal apparatus has a function to determine a transmission power using a calculation method of a transmission power determined in advance for every communication terminal apparatus, and

in said second access method, changes a calculation method of a transmission power in accordance with a frequency bandwidth allocated discretely.

4. The wireless communication system according to claim 2 or 3, wherein in said frequency bandwidth allocated discretely, transmission power control is performed in accordance with the narrowest bandwidth.

5. The wireless communication system according to claim 2 or 3, wherein in said second access method, transmission power control is performed in accordance with the number of divisions of a spectrum when frequency domain signals is allocated to discrete frequency bands.

6. The wireless communication system according to claim 4, wherein transmission power control is performed in accordance with a moving speed of said communication terminal apparatus.

7. The wireless communication system according to claim 4, wherein said communication control apparatus performs transmission power control in accordance with a required time until said communication terminal apparatus starts transmission of data after transmitting a known signal used for channel estimation.

8. The wireless communication system according to claim 4, wherein said communication control apparatus performs transmission power control in accordance with a frequency bandwidth which said communication terminal apparatus uses and a frequency bandwidth which said communication control apparatus can allocate.

9. The wireless communication system according to claim 2 or 3, wherein said communication control apparatus, when said communication terminal apparatus carries out transmission diversity, performs transmission power control in accordance with the number of transmission antennas which said communication terminal apparatus uses.

10. The wireless communication system according to claim 2 or 3, wherein said communication control apparatus, when said communication terminal apparatus carries out MIMO (Multiple-Input Multiple-Output), performs transmission power control in accordance with the number of transmission antennas which said communication terminal apparatus uses.

11. The wireless communication system according to claim 2 or 3, wherein said communication control apparatus, when said communication terminal apparatus carries out MIMO, performs transmission power control in accordance with the number of receiving antennas to be used.

12. A communication control apparatus applied to a wireless communication system in which a communication control apparatus and a communication terminal apparatus that are able to use a plurality of types of access methods perform wireless communication using any of the access methods, wherein

said communication control apparatus, when the necessity of changing the access method arises, determines the access method after change and notifies said communication terminal apparatus of switching the access method before change to said determined access method, and

performs transmission power control in accordance with communication characteristics of said determined access method.

13. The communication control apparatus according to claim 12, wherein

said plurality of types of access methods includes a first access method that allocates frequency domain signals to contiguous frequency bands, and a second access method that allocates frequency domain signals to discrete frequency bands, and

in said second access method, in accordance with a frequency bandwidth allocated discretely, a control amount of the transmission power is changed by a control signal and is notified of.

14. A communication terminal apparatus applied to a wireless communication system in which a communication control apparatus and a communication terminal apparatus that are able to use a plurality of types of access methods perform wireless communication using any of the access methods, wherein,

said plurality of types of access methods includes a first access method that allocates frequency domain signals to contiguous frequency bands and a second access method that allocates frequency domain signals to discrete frequency bands, and

said communication terminal apparatus has a function to determine a transmission power using a calculation method of a transmission power determined in advance for every communication terminal apparatus, and

in said second access method, changes a calculation method of a transmission power in accordance with a frequency bandwidth allocated discretely.

15. A control program of a communication control apparatus applied to a wireless communication system in which a communication control apparatus and a communication terminal apparatus that are able to use a plurality of types of access methods perform wireless communication using any of the access methods, said control program converting a series of processing into computer-readable and computer-executable commands, said series of processing comprising:

judging whether the necessity of changing an access method arises;

determining, when the necessity of changing an access method arises as a result of said judgment, an access method after change;

notifying said communication terminal apparatus of switching an access method before change to said determined access method; and

performing transmission power control in accordance with communication characteristics of said determined access method.