Multi-stage transmit power control scheme for access point

• US 9,055,541 B2
• Filed: 01/20/2014
• Issued: 06/09/2015
• Est. Priority Date: 02/12/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Patel, Chirag Sureshbhai, Yavuz, Mehmet, Grokop, Leonard Henry, Chande, Vinay, Nanda, Sanjiv, Meshkati, Farhad, Nagaraja, Sumeeth
• Primary Examiner(s): TRINH, TAN H
• Application Number:
  US14/159,294
• Publication Number:
  US 20140135004A1
• Time in Patent Office: 505 Days
• Field of Search: 455/513, 455/423, 455/67.13, 455/435.1, 455/422.1, 455/522, 455/69, 455/68, 455/127.1, 455/67.11, 455/445, 455/517, 455/561, 455/41.2, 455/452.2, 455/444, 455/63.1, 455/501, 370/343, 370/310, 370/328, 370/329, 370/338, 726/3
• US Class Current: 1/1
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• 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 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

Transmit power for an access point is controlled based on information received by the access point. For example, an access point may employ one or more algorithms that use messages received from nearby access terminals to maintain an acceptable tradeoff between providing an adequate coverage area for access point transmissions and mitigating interference that these transmissions cause at nearby access terminals. Here, the access point may employ a network listen-based algorithm upon initialization of the access terminal to provide preliminary transmit power control until sufficient information is collected for another transmit power control algorithm (e.g., an access terminal assisted algorithm). Also, the access terminal may employ an active access terminal protection scheme to mitigate interference the access point may otherwise cause to a nearby access terminal that is in active communication with another access point.

Claims

1. A method of communication, comprising:

maintaining information indicative of a desired coverage range for an access point;

receiving signals on at least one carrier frequency at the access point, wherein the signals are received from at least one other access point that transmits on at least one forward link on the at least one carrier frequency, and wherein the signals include a number of messages;

determining signal strength information associated with the signals;

setting transmit power limits for a transmit power algorithm based on the determined signal strength information and the maintained coverage range information; and

controlling transmit power of the access point according to the transmit power algorithm and the number of messages.

2. The method of claim 1, further comprising:

determining that an initialization procedure has commenced for the access point; and

triggering the setting of the transmit power limits based on the determined signal strength information and the maintained information as a result of a determination that the initialization procedure has commenced.

3. The method of claim 1, further comprising:

receiving additional signals on the at least one carrier frequency at the access point;

determining additional signal strength information associated with the additional signals;

determining that there has been a change in channel quality on the at least one carrier frequency based on a difference between the determined signal strength information and the determined additional signal strength information; and

adjusting the transmit power limits based on a determination that there has been a change in the channel quality.

4. The method of claim 1, further comprising receiving registration messages at the access point, wherein the transmit power algorithm controls the transmit power based on the registration messages.

5. The method of claim 1, wherein:

wherein the messages are indicative of channel quality on a forward link carrier frequency of the access point, on a beacon carrier frequency of the access point, or on a forward link carrier frequency and a beacon carrier frequency of the access point.

6. The method of claim 1, wherein the controlling of the transmit power according to the number of messages comprises:

determining that the number of messages is greater than or equal to a sufficient number of messages; and

triggering a setting of new transmit power limits for the transmit power algorithm based on a determination that the number of messages is greater than or equal to the sufficient number of messages.

7. The method of claim 1, wherein:

the messages comprise channel quality reports and registration messages, and the number of messages comprises a number of registration messages corresponding to a quantity of registration attempts made by at least one access terminal over a period of time;

the at least one access terminal is not authorized to receive active mode service via the access point;

the controlling of the transmit power further comprises setting new transmit power limits based on the channel quality reports; and

the transmit power algorithm adjusts the transmit power within the new transmit power limits based on the number of registration messages.

8. The method of claim 1, wherein the controlling of the transmit power comprises controlling beacon transmit power of the access point, controlling forward link transmit power of the access point, or controlling beacon transmit power and forward link transmit power of the access point.

9. The method of claim 1, wherein the determination of the signal strength information comprises measuring pilot energy of pilot signals received from the at least one other access point, measuring signal power of signals received from the at least one other access point, or measuring pilot energy or signal power of signals received from the at least one other access point.

10. An apparatus for communication, comprising:

a memory component operable to maintain information indicative of a desired coverage range for the apparatus;

a receiver operable to receive signals on at least one carrier frequency from at least one access point that transmits on at least one forward link on the at least one carrier frequency, and wherein the signals include a number of messages; and

a controller operable to determine signal strength information associated with the signals, and further operable to set transmit power limits for a transmit power algorithm based on the determined signal strength information and the maintained coverage range information, and further operable to control transmit power of the apparatus according to the transmit power algorithm and the number of messages.

11. The apparatus of claim 10, wherein the controller is further operable to:

determine that an initialization procedure has commenced for the apparatus; and

trigger the setting of the transmit power limits based on the determined signal strength information and the maintained information as a result of a determination that the initialization procedure has commenced.

12. The apparatus of claim 10, wherein:

the receiver is further operable to receive additional signals on the at least one carrier frequency;

the controller is further operable to determine additional signal strength information associated with the additional signals;

the controller is further operable to determine that there has been a change in channel quality on the at least one carrier frequency based on a difference between the determined signal strength information and the determined additional signal strength information; and

the controller is further operable to adjust the transmit power limits based on a determination that there has been a change in the channel quality.

13. The apparatus of claim 10, wherein:

the receiver is further operable to receive registration messages; and

the transmit power algorithm controls the transmit power based on the registration messages.

14. The apparatus of claim 10, wherein:

the messages are indicative of channel quality on a forward link carrier frequency of the apparatus, on a beacon carrier frequency of the apparatus, or on a forward link carrier frequency and a beacon carrier frequency of the apparatus.

15. An apparatus for communication, comprising:

means for maintaining information indicative of a desired coverage range for the apparatus;

means for receiving signals on at least one carrier frequency from at least one access point that transmits on at least one forward link on the at least one carrier frequency, and wherein the signals include a number of messages;

means for determining signal strength information associated with the signals;

means for setting transmit power limits for a transmit power algorithm based on the determined signal strength information and the maintained coverage range information; and

means for controlling transmit power of the apparatus according to the transmit power algorithm and the number of messages.

16. The apparatus of claim 15, further comprising:

means for determining that an initialization procedure has commenced for the apparatus; and

means for triggering the setting of the transmit power limits based on the determined signal strength information and the maintained information as a result of a determination that the initialization procedure has commenced.

17. The apparatus of claim 15, further comprising:

means for receiving additional signals on the at least one carrier frequency;

means for determining additional signal strength information associated with the additional signals;

means for determining that there has been a change in channel quality on the at least one carrier frequency based on a difference between the determined signal strength information and the determined additional signal strength information; and

means for adjusting the transmit power limits based on a determination that there has been a change in the channel quality.

18. The apparatus of claim 15, further comprising means for receiving registration messages, wherein the transmit power algorithm controls the transmit power based on the registration messages.

19. The apparatus of claim 15, wherein the messages are indicative of channel quality on a forward link carrier frequency of the apparatus, on a beacon carrier frequency of the apparatus, or on a forward link carrier frequency and a beacon carrier frequency of the apparatus.

20. A non-transitory

computer-readable medium storing computer executable code, comprising:

code for maintaining information indicative of a desired coverage range for an access point;

code for receiving signals on at least one carrier frequency at the access point, wherein the signals are received from at least one other access point that transmits on at least one forward link on the at least one carrier frequency, and wherein the signals include a number of messages;

code for determining signal strength information associated with the received signals;

code for setting transmit power limits for a transmit power algorithm based on the determined signal strength information and the maintained coverage range information; and

code for controlling transmit power of the access point according to the transmit power algorithm and the number of messages.

21. The computer-readable medium of claim 20, further comprising:

code for determining that an initialization procedure has commenced for the access point; and

code for triggering the setting of the transmit power limits based on the determined signal strength information and the maintained information as a result of a determination that the initialization procedure has commenced.

22. The computer-readable medium of claim 20, further comprising:

code for receiving additional signals on the at least one carrier frequency at the access point;

code for determining additional signal strength information associated with the additional signals;

code for determining that there has been a change in channel quality on the at least one carrier frequency based on a difference between the determined signal strength information and the determined additional signal strength information; and

code for adjusting the transmit power limits based on a determination that there has been a change in the channel quality.

23. The computer-readable medium of claim 20, further comprising:

code for receiving registration messages at the access point, wherein the transmit power algorithm controls the transmit power based on the registration messages.

24. The computer-readable medium of claim 20, wherein the messages are indicative of channel quality on a forward link carrier frequency of the access point, on a beacon carrier frequency of the access point, or on a forward link carrier frequency and a beacon carrier frequency of the access point.