Transmit power control

• US 20080045271A1
• Filed: 06/15/2007
• Published: 02/21/2008
• Est. Priority Date: 07/04/2006
• Status: Abandoned Application

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Azuma, Tomohiro
• Application Number:
  US11/812,191
• Publication Number:
  US 20080045271A1
• Time in Patent Office: Days
• US Class Current: 455/561
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/221 using past power control commands
• CPC Class Codes: H04W 52/223 predicting future states of the transmission
• CPC Class Codes: H04W 52/228 using past power values or information
• 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 52/281 taking into account user or data type priority
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

The invention discloses transmit power control that easily controls transmit power for transmitting a signal to a mobile terminal so that the transmit power has an optimal value. When there is a succession of transmit power control information transmitted from a mobile terminal to the radio base station, that includes an instruction to raise transmit power, during a period from when a calculated total transmit power, based on power information of a multiple signal that is obtained by multiplexing signals transmitted by each mobile terminal, exceeds a preliminarily set power threshold to when the total transmit power falls below the preliminarily set power threshold, the transmit power control information is converted to transmit power control information that includes an instruction to maintain transmit power at a constant level. The transmit power is controlled based on the converted transmit power control information. The signal is transmitted to the mobile terminal by use of the controlled transmit power.

Claims

1. A radio base station, wherein when there is a succession of transmit power control information transmitted from a mobile terminal, containing an instruction to raise transmit power for transmitting a signal to the mobile terminal, during a period from when the calculated total transmit power, based on power information of a multiple signal that is obtained by multiplexing signals transmitted by each mobile terminal, exceeds a preliminarily set power threshold to when the total transmit power falls below the preliminarily set power threshold, the transmit power control information is converted to transmit power control information indicating an instruction to maintain transmit power at a constant level, and wherein the transmit power is controlled based on the converted transmit power control information, and wherein the signal is transmitted to the mobile terminal by use of the controlled transmit power.

2. The radio base station according to claim 1, wherein the power threshold is set as a suppression start power threshold and a suppression cancel power threshold, and wherein when the total transmit power exceeds the suppression start power threshold, the conversion is started, and wherein when the total transmit power falls below the suppression cancel power threshold, the conversion is cancelled.

3. The radio base station according to claim 1, wherein an order of priority of the mobile terminal is determined, and wherein when the total transmit power falls below the suppression cancel power threshold, the conversion is cancelled according to the order of priority sequentially for each mobile terminal.

4. The radio base station according to claim 3, wherein the order of priority is determined based on previously accumulated results of the transmit power control information.

5. The radio base station according to claim 3, wherein the order of priority is determined based on a set power that is set for each mobile terminal.

6. The radio base station according to claim 3, wherein the order of priority is determined based on reception SIR transmitted from the mobile terminal.

7. A radio base station, wherein a control quantity of transmit power for transmitting a signal to a mobile terminal is determined based on a calculated total transmit power based on power information of a multiple signal obtained by multiplexing signals transmitted by each mobile terminal, and wherein the transmit power is controlled based on the determined control quantity and transmit power control information transmitted from the mobile terminal, and wherein the signal is transmitted to the mobile terminal by use of the controlled transmit power.

8. The radio base station according to claim 7, wherein when the total transmit power exceeds a control quantity threshold for determining the control quantity, the control quantity is varied.

9. The radio base station according to claim 7, wherein when the total transmit power falls below a control quantity threshold for determining the control quantity, the control quantity is varied.

10. The radio base station according to claim 7, wherein a different control quantity is determined for each mobile terminal that is a destination of the signal.

11. A method for use in a radio base station that controls transmit power for transmitting a signal to a mobile terminal based on transmit power control information transmitted from the mobile terminal, the method comprising:

a step in which when there is a succession of transmit power control information indicating an instruction to raise transmit power, during a period from when a calculated total transmit power, based on power information of a multiple signal that is obtained by multiplexing signals transmitted by each mobile terminal, exceeds a preliminarily set power threshold to when the total transmit power falls below the preliminarily set power threshold, the transmit power control information is converted to transmit power control information indicating an instruction to maintain transmit power at a constant level;

a step of controlling the transmit power based on the converted transmit power control information; and

a step of transmitting the signal to the mobile terminal by use of the controlled transmit power.

12. The method according to claim 11, wherein the power threshold is set as a suppression start power threshold and a suppression cancel power threshold, the method further comprising:

a step in which, and when the total transmit power exceeds the suppression start power threshold, the conversion is started; and

a step in which when the total transmit power falls below the suppression cancel power threshold, the conversion is cancelled.

13. The method according to claim 11, further comprising:

a step of determining an order of priority of the mobile terminal; and

a step in which when the total transmit power falls below the suppression cancel power threshold, the conversion is cancelled according to the order of priority sequentially for each mobile terminal.

14. The method according to claim 13, further comprising a step of determining the order of priority based on previously accumulated results of the transmit power control information.

15. The method according to claim 13, further comprising a step of determining the order of priority based on a set power that is set for each mobile terminal.

16. The method according to claim 13, further comprising a step of determining the order of priority based on reception SIR transmitted from the mobile terminal.

17. A method for use in a radio base station that controls transmit power for transmitting a signal to a mobile terminal based on transmit power control information transmitted from the mobile terminal, the method comprising:

a step of determining a control quantity of the transmit power based on a calculated total transmit power based on power information of a multiple signal obtained by multiplexing signals transmitted by each mobile terminal;

a step of controlling the transmit power based on the determined control quantity and the transmit power control information; and

a step of transmitting the signal to the mobile terminal by use of the controlled transmit power.

18. The method according to claim 17, further comprising a step of varying the control quantity when the total transmit power exceeds a control quantity threshold for determining the control quantity.

19. The method according to claim 17, further comprising a step of varying the control quantity when the total transmit power falls below a control quantity threshold for determining the control quantity.

20. The method according to claim 17, further comprising a step of determining a different control quantity for each mobile terminal that is a destination of the signal.