Adaptation of transmit power based on maximum received signal strength

• US 8,700,083 B2
• Filed: 08/06/2008
• Issued: 04/15/2014
• Est. Priority Date: 08/10/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Yavuz, Mehmet, Black, Peter J., Nanda, Sanjiv
• Primary Examiner(s): Alam, Fayyaz
• Application Number:
  US12/187,307
• Publication Number:
  US 20090042594A1
• Time in Patent Office: 2,078 Days
• Field of Search: 455/522, 455 69- 70, 370318-320
• US Class Current: 455/522
• CPC Class Codes: H04W 16/16 for PBS [Private Base Station] arrangements
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

Transmit power (e.g., maximum transmit power) may be defined based on the maximum received signal strength allowed by a receiver and a minimum coupling loss from a transmitting node to a receiver. Transmit power may be defined for an access node (e.g., a femto node) such that a corresponding outage created in a cell (e.g., a macro cell) is limited while still providing an acceptable level of coverage for access terminals associated with the access node. An access node may autonomously adjust its transmit power based on channel measurement and a defined coverage hole to mitigate interference. Transmit power may be defined based on channel quality. Transmit power may be defined based on a signal-to-noise ratio at an access terminal. The transmit power of neighboring access nodes also may be controlled by inter-access node signaling.

Claims

1. A method of wireless communication, comprising:

determining a maximum received signal strength at which a wireless subscriber terminal is permitted to receive downlink signals from a base station;

determining a minimum coupling loss between the wireless subscriber terminal and the base station in a coverage area of the base station; and

determining a transmit power value based on the determined maximum received signal strength and the determined minimum coupling loss,

wherein the transmit power value includes a maximum transmission power level at which the base station is permitted to transmit to the wireless subscriber terminal.

2. The method of claim 1, wherein the transmit power value comprises a given transmit power value for a common control channel.

3. The method of claim 1, wherein the maximum received signal strength and the minimum coupling loss are predefined.

4. The method of claim 1, further comprising receiving an indication of the maximum received signal strength.

5. The method of claim 1, wherein the determination of the minimum coupling comprises:

receiving an indication of received signal strength from a node; and

determining the minimum coupling loss based on the received indication.

6. The method of claim 1, wherein operation of the base station is restricted to:

signaling, data access, registration, paging, and/or service to at least one wireless subscriber terminal.

7. The method of claim 1, wherein the base station corresponds to a femto node or a pico node.

8. The method of claim 1, wherein the maximum transmission power level corresponds to a first preliminary maximum transmit power value, the method further comprising:

determining at least one other preliminary maximum transmit power value; and

determining a maximum transmit power value based on a minimum of the first and at least one other preliminary maximum transmit power values.

9. An apparatus for wireless communication, comprising:

a signal strength determiner configured to determine a maximum received signal strength at which a wireless subscriber terminal is permitted to receive downlink signals from a base station;

a coupling loss determiner configured to determine a minimum coupling loss between the wireless subscriber terminal and the base station in a coverage area of the base station; and

a transmit power controller configured to determine a transmit power value based on the determined maximum received signal strength and the determined minimum coupling loss,

wherein the transmit power value includes a maximum transmission power level at which the base station is permitted to transmit to the wireless subscriber terminal.

10. The apparatus of claim 9, wherein the transmit power value comprises a transmit power value for a common control channel.

11. The apparatus of claim 9, wherein operation of the base station is restricted to signaling, data access, registration, paging, and/or service to at least one wireless subscriber terminal.

12. The apparatus of claim 9, wherein the base station corresponds to a femto node or a pico node.

13. The apparatus of claim 9, wherein:

the maximum transmission power level corresponds to a first preliminary maximum transmit power value; and

the transmit power controller is further configured to determine at least one other preliminary maximum transmit power value, and to determine a maximum transmit power value based on a minimum of the first and at least one other preliminary maximum transmit power values.

14. An apparatus for wireless communication, comprising:

means for determining a maximum received signal strength at which a wireless subscriber terminal is permitted to receive downlink signals from a base station;

means for determining a minimum coupling loss between the wireless subscriber terminal and the base station in a coverage area of the base station; and

means for determining a transmit power value based on the determined maximum received signal strength and the determined minimum coupling loss,

wherein the transmit power value includes a maximum transmission power level at which the base station is permitted to transmit to the wireless subscriber terminal.

15. The apparatus of claim 14, wherein the transmit power value comprises a given transmit power value for a common control channel.

16. The apparatus of claim 14, wherein operation of the base station is restricted to signaling, data access, registration, paging, and/or service to at least one wireless subscriber terminal.

17. The apparatus of claim 14, wherein the base station corresponds to a femto node or a pico node.

18. The apparatus of claim 14, wherein:

the maximum transmission power level corresponds to a first preliminary maximum transmit power value; and

the means for determining a transmit power value is configured to determine at least one other preliminary maximum transmit power value, and to determine a maximum transmit power value based on a minimum of the first and at least one other preliminary maximum transmit power values.

19. A non-transitory computer-readable medium comprising code for causing a computer to:

determine a maximum received signal strength at which a wireless subscriber terminal is permitted to receive downlink signals from a base station;

determine a minimum coupling loss between the wireless subscriber terminal and the base station in a coverage area of the base station; and

determine a transmit power value based on the determined maximum received signal strength of the receiver and the determined minimum coupling loss,

wherein the transmit power value includes a maximum transmission power level at which the base station is permitted to transmit to the wireless subscriber terminal.

20. The non-transitory computer-readable medium of claim 19, wherein the transmit power value comprises a given transmit power value for a common control channel.

21. The non-transitory computer readable medium of claim 19, wherein operation of the base station restricted to:

signaling, data access, registration, paging, and/or service to a east one wireless subscriber terminal.

22. The non-transitory computer-readable medium of claim 19, wherein the base station corresponds to a femto node or a pico node.

23. The non-transitory computer-readable medium of claim 19, wherein:

the maximum transmission power level corresponds to a first preliminary maximum transmit power value; and

the non-transitory computer-readable medium further comprises code for causing the computer to determine at least one other preliminary maximum transmit power value, and to determine a maximum transmit power value based on a minimum of the first and at least one other preliminary maximum transmit power values.