Power control of remote communication devices

• US 6,169,907 B1
• Filed: 10/21/1997
• Issued: 01/02/2001
• Est. Priority Date: 10/21/1997
• Status: Expired due to Term

• Current Assignee: Altobridge Limited (Singapore Technologies Engineering Limited)
• Original Assignee: Interwave Communications International SA (Alvarion Limited)
• Inventors: Chang, Yu-Wen, Chao, Pi-Hui
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Bhattacharya, Sam
• Application Number:
  US08/954,865
• Time in Patent Office: 1,169 Days
• Field of Search: 455/69, 455/67.1, 455/70, 455/126, 455/127, 455/343, 455/522
• US Class Current: 455/522
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/221 using past power control commands
• 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

A first communication device is in communication with a second communication device. The communication may be characterized by a first and a second characteristic that are affected by a transmit power of the first communication device, each characteristic having an upper and a lower bound. The transmit power of the first communication device is delayed from being adjusted to bring the communication within the upper and lower bounds of the first criteria and outside the upper and lower bounds of the second criteria when a contrary adjustment of the transmit power of the first communication device was performed until a predetermined amount of time has expired since the contrary adjustment. Thus, unnecessarily repetitive power adjustments are avoided.

Claims

1. A method of controlling a transmit power of a first communication device, the first communication device being in communication with a second communication device in a communication system, wherein a first and a second criteria define a communication between the first and second communication devices, each of the first and second criteria having an upper bound and a lower bound, such that an adjustment of the transmit power of the first communication device affects the first and second criteria, the method comprising:

preventing an adjustment of the transmit power of the first communication device to thereby bring the communication

(i) within the upper and lower bounds of the first criteria, and

(ii) outside the upper and lower bounds of the second criteria,

wherein preventing the adjustment is conditioned upon a contrary adjustment of the transmit power of the first communication device being performed, and a predetermined amount of time having expired since the contrary adjustment.

2. A method of controlling a transmit power of a first communication device, the first communication device being in communication with a second communication device in a communication system, wherein a first and a second characteristic define a communication between the first and second communication devices, the method comprising:

monitoring the first characteristic, the first characteristic having a value wherein an increase in transmit power increases the value of the first characteristic;

setting an upper and a lower bound for the value of the first characteristic; and

determining if the value of the first characteristic has fallen below the lower bound of the first characteristic, wherein an increase of the transmit power of the first communication device is delayed until a first predetermined amount of time has expired provided that a previous power adjustment command caused the transmit power to be decreased.

3. A method as recited in claim 2, the method further comprising:

determining if the value of the first characteristic has risen above the upper bound of the first characteristic, wherein a decrease of the transmit power of the first communication device is delayed until a second predetermined amount of time has expired provided that a previous power adjustment command caused the transmit power to be increased.

4. A method as recited in claim 3, the method further comprising:

monitoring the second characteristic, the second characteristic having a value wherein an increase in transmit power increases the value of the second characteristic;

setting an upper and a lower bound for the value of the second characteristic; and

determining if the value of the second characteristic has fallen below the lower bound of the second characteristic, wherein an increase of the transmit power of the first communication device is delayed until a third predetermined amount of time has expired provided that the previous power adjustment command caused the transmit power to be decreased.

5. A method as recited in claim 4, the method further comprising:

determining if the value of the second characteristic has risen above the upper bound of the second characteristic, wherein a decrease of the transmit power of the first communication device is delayed until a fourth predetermined amount of time has expired provided that the previous power adjustment command caused the transmit power to be increased.

6. A method of controlling a transmit power of a first communication device, the first communication device being in communication with a second communication device in a communication system, wherein a first and second characteristic define a communication between the first and second communication devices, the method comprising:

monitoring the first characteristic, the first characteristic having a value wherein an increase in transmit power increases the value of the first characteristic;

setting an upper and a lower bound for the value of the first characteristic; and

determining if the value of the first characteristic has fallen below the lower bound of the first characteristic, wherein an increase of the transmit power of the first communication device is delayed until a first predetermined amount of time has expired provided that a previous power adjustment command caused the transmit power to be decreased;

determining if the value of the first characteristic has risen above the upper bound of the first characteristic, wherein a decrease of the transmit power of the first communication device is delayed until a second predetermined amount of time has expired provided that the previous power adjustment command caused the transmit power to be increased;

monitoring the second characteristic, the second characteristic having a value wherein an increase in transmit power increases the value of the second characteristic;

setting an upper and a lower bound for the value of the second characteristic;

determining if the value of the second characteristic has fallen below the lower bound of the second characteristic, wherein the increase of the transmit power of the first communication device is delayed until a third predetermined amount of time has expired provided that the previous power adjustment command caused the transmit power to be decreased; and

determining if the value of the second characteristic has risen above the upper bound of the second characteristic wherein the decrease of the transmit power of the first communication device is delayed until a fourth predetermined amount of time has expired provided that the previous power adjustment command caused the transmit power to be increased.

7. A method as recited in claim 6, wherein the operations of determining whether the values of the first or second characteristic have fallen below their respective lower bounds is performed before the operations of determining whether the values of the first or second characteristic have risen above their respective upper bounds.

8. A method as recited in claim 6, wherein the transmit power of the first communication device is adjusted by a current power adjustment command after an appropriate predetermined amount of time has expired.

9. A method as recited in claim 8, the method further comprising:

limiting the current power adjustment command, such that if the current power adjustment command increases the transmit power of the first communication device, the current power adjustment command is limited to a maximum power output of the first communication device.

10. A method as recited in claim 8, the method further comprising:

limiting the current power adjustment command if the first communication device is not permitted to exceed the upper bound of the first characteristic, such that if the current power adjustment command increases the transmit power of the first communication device, the current power adjustment command is limited to an upper transmit power level.

11. A method as recited in claim 8, the method further comprising:

limiting the current power adjustment command if the first communication device is not permitted to exceed the upper bound of the second characteristic, such that if the current power adjustment command increases the transmit power of the first communication device, the current power adjustment command is limited to an upper transmit power level.

12. A method as recited in claim 8, the method further comprising:

limiting the current power adjustment command, such that if the current power adjustment command decreases the transmit power of the first communication device, the current power adjustment command is limited to a minimum power output of the first communication device.

13. A method as recited in claim 8, the method further comprising:

limiting the current power adjustment command if the first communication device is not permitted to fall below the lower bound of the first characteristic, such that if the current power adjustment command decreases the transmit power of the first communication device, the current power adjustment command is limited to a lower transmit power level.

14. A method as recited in claim 8, the method further comprising:

limiting the current power adjustment command if the first communication device is not permitted to fall below the lower bound of the second characteristic, such that if the current power adjustment command decreases the transmit power of the first communication device, the current power adjustment command is limited to a lower transmit power level.

15. A communication system comprising:

a mobile station; and

a base transceiver station being in communication with the mobile station, the communication of the base transceiver station with the mobile station being characterized by a first characteristic having an upper and a lower threshold, the base transceiver station being configured to control the transmit power of the mobile station, wherein the base transceiver station waits until a first predetermined amount of time has expired to increase the transmit power of the mobile station when a value of the first characteristic falls below the lower threshold of the first characteristic provided that the base transceiver station previously decreased the transmit power of the mobile station.

16. A communication system as recited in claim 15, wherein the base transceiver station waits until a second predetermined amount of time has expired to decrease the transmit power of the mobile station when the value of the first characteristic rises above the upper threshold of the first characteristic provided that the base transceiver station previously increased the transmit power of the mobile station.

17. A communication system as recited in claim 16, the communication of the base transceiver station with the mobile station being characterized by a second characteristic having an upper and a lower threshold, wherein the base transceiver station waits until a third predetermined amount of time has expired to increase the transmit power of the mobile station when the value of the second characteristic falls below the lower threshold of the second characteristic provided that the base transceiver station previously decreased the transmit power of the mobile station.

18. A communication system as recited in claim 17, wherein the base transceiver station waits until a fourth predetermined amount of time has expired to decrease the transmit power of the mobile station when the value of the second characteristic rises above the upper threshold of the second characteristic provided that the base transceiver station previously increased the transmit power of the mobile station.

19. A communication system having a mobile station and a base transceiver station, wherein the mobile station and the base transceiver station are in communication, the communication being characterized by a first and a second characteristic, each of the first and second characteristics having an upper and a lower bound, the communication system comprising:

a power control means, the power control means controlling the transmit power of the mobile station, wherein the power control means prevents a present adjustment of the transmit power of the mobile station provided that a contrary adjustment of the transmit power of the mobile station was performed, and the present adjustment is not performed until a predetermined amount of time has expired since the contrary adjustment, the prevention of the present adjustment thereby bringing the communication within the upper and lower bounds of the first characteristic and outside the upper and lower bounds of the second characteristic.

20. A method of controlling a transmit power of a first communication device, the first communication device being in communication with a second communication device in a communication system, wherein first and second criteria define a communication between the first and second communication devices, each of the first and second criteria having an upper bound and a lower bound, such that an adjustment of the transmit power of the first communication device affects the first and second criteria, the method comprising:

preventing a present adjustment of the transmit power of the first communication device to bring the communication within the upper and lower bounds of the first criterion and outside the upper and lower bounds of the second criterion, provided that a contrary adjustment of the transmit power of the first communication device was performed in a preceding measurement interval, the preventing step extending until a predetermined amount of time has expired since the contrary adjustment, wherein the first and the second criteria are measured by the communication system at each successive measurement interval, and wherein the predetermined amount of time comprises at least two measurement intervals.

21. The method of claim 20, wherein the first criterion comprises signal-to-noise ratio and the second criterion comprises bit error rate.

22. The method of claim 20, wherein said step of preventing a present adjustment of transmit power includes the steps of:

measuring power and quality levels of the signal;

decrementing a timer until the predetermined amount of time has passed;

determining a power command for adjustment of the transmit power;

sending the power command.

23. The method of claim 22, wherein the power command is incremented by a predetermined step.

24. The method of claim 23, wherein the predetermined step is related to the signal quality.

25. The method of claim 23, wherein the predetermined step is related to the signal power.

26. The method of claim 23, wherein the predetermined step is related to the signal quality and power.