APPARATUS AND METHOD FOR ADJUSTMENT OF TRANSMITTER POWER IN A SYSTEM

• US 20120021707A1
• Filed: 07/25/2011
• Published: 01/26/2012
• Est. Priority Date: 07/26/2010
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lu, Lin, Mahajan, Amit, Hamdy, Walid M., Ngai, Francis M., Forrester, John A., Guckian, Paul, Shahadi, Reza
• Application Number:
  US13/190,228
• Publication Number:
  US 20120021707A1
• Time in Patent Office: Days
• US Class Current: 455/103
• CPC Class Codes: H04W 52/226 using past references to control power, e.g. look-up-table
• CPC Class Codes: H04W 52/281 taking into account user or data type priority
• CPC Class Codes: H04W 52/30 using constraints in the total amount of available transmission power
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

Certain aspects of the present disclosure propose methods for determining power level of one or more transmitters based on a power level of a primary transmitter when the transmitters are located in close proximity of each other. The power levels may be determined such that a combined power of all the transmitters is compliant with regulatory radio frequency (RF) safety requirements. For certain aspects, power level of the lower priority transmitters may be determined utilizing one or more look-up tables. For another aspect, power level of the lower priority transmitters may be calculated using an algorithm based on the power level of the priority transmitter. In aspects, the power level of lower priority transmitters and the time duration for which the transmitters are active may be selected dynamically so that the time averaged power of the transmitters for a defined period of time falls below the RF exposure limit.

Claims

1. A method for wireless communications, comprising:

identifying a power level for a first transmitter unit;

selecting a power identifier for a second transmitter unit from one or more look-up tables based at least on the power level, wherein the first and the second transmitter units operate near simultaneously using one or more transmit antennas; and

adjusting transmit power levels of at least one of the first and the second transmitter units based on the power level and the power identifier, wherein the transmit power levels of the first and the second transmitter units are less than or equal to an allowable power level which is determined based on a radio frequency (RF) exposure limit.

2. The method of claim 1, wherein the one or more look-up tables comprise at least one of a plurality of predetermined power values or a plurality of predetermined power adjustment values.

3. The method of claim 2, wherein the predetermined power adjustment values correspond to the second transmitter unit.

4. The method of claim 1, wherein the one or more look-up tables correspond to one or more transmission frequencies.

5. The method of claim 1, further comprising:

determining priority of the first and the second transmitter units; and

adjusting power of a transmitter unit with a lower priority.

6. The method of claim 5, wherein determining priority of the first and the second transmitter units comprises:

determining priority of the first and the second transmitter units based on one or more of data priorities, available frequency bands, load of a network, radio frequency conditions, available technologies, and cost of data connection.

7. The method of claim 1, wherein the first and the second transmitter units are located on different apparatuses.

8. The method of claim 1, wherein two or more transmit power levels of two or more transmitter units are adjusted.

9. A method for wireless communications, comprising:

identifying a first power level for a first transmitter unit; and

dynamically selecting at least one of a second power level or an active time period for a second transmitter unit based on the first power level, wherein a total power used by the first and the second transmitter units is less than or equal to an allowable power level which is determined based on a radio frequency (RF) exposure limit, and the first and the second transmitter units operate near simultaneously using one or more transmit antennas.

10. The method of claim 9, wherein dynamically selecting the second power level comprises:

selecting the second power level based on one or more of a regulatory radio frequency (RF) exposure limit, a target margin to the RF exposure limit and measured specific absorption limit (SAR) values for the first and the second transmitter units.

11. The method of claim 9, wherein dynamically selecting the active time period comprises:

selecting the active time period for the second transmitter unit to adjust an average transmit power of the second transmitter unit.

12. The method of claim 9, further comprising:

selecting an active time period and a power level for the first transmitter unit to adjust an average transmit power of the first transmitter unit; and

adjusting the transmit power level of the first transmitter unit based on the selected active time period and the selected power level for the first transmitter unit.

13. The method of claim 9, wherein the first and the second transmitter units are located on different apparatuses.

14. The method of claim 9, further comprising:

determining priority of the first and the second transmitter units; and

maintaining at least one of power level or active time period of a transmitter unit that has a higher priority and adjusting power level or active time period of a transmitter unit with a lower priority.

15. A method for wireless communications, comprising:

identifying a first power level for a first transmitter unit; and

dynamically selecting at least one of a second power level or an active time period for the first transmitter unit based on the first power level, wherein an average power used by the first transmitter unit for a period of time is less than or equal to an allowable power level which is determined based on at least one of a radio frequency (RF) exposure limit, a target margin to the RF exposure limit or a measured specific absorption limit (SAR) value for the first transmitter unit.

16. An apparatus for wireless communications, comprising:

means for identifying a power level for a first transmitter unit;

means for selecting a power identifier for a second transmitter unit from one or more look-up tables based at least on the power level, wherein the first and the second transmitter units operate near simultaneously using one or more transmit antennas; and

means for adjusting transmit power levels of at least one of the first and the second transmitter units based on the power level and the power identifier, wherein the transmit power levels of the first and the second transmitter units are less than or equal to an allowable power level which is determined based on a radio frequency (RF) exposure limit.

17. The apparatus of claim 16, wherein the one or more look-up tables comprise at least one of a plurality of predetermined power values or a plurality of predetermined power adjustment values.

18. The apparatus of claim 17, wherein the predetermined power adjustment values correspond to the second transmitter unit.

19. The apparatus of claim 16, wherein the one or more look-up tables correspond to one or more transmission frequencies.

20. The apparatus of claim 16, further comprising:

means for determining priority of the first and the second transmitter units; and

means for adjusting power of a transmitter unit with a lower priority.

21. The apparatus of claim 20, wherein the means for determining priority of the first and the second transmitter units comprises:

means for determining priority of the first and the second transmitter units based on one or more of data priorities, available frequency bands, load of a network, radio frequency conditions, available technologies, and cost of data connection.

22. The apparatus of claim 16, wherein the first and the second transmitter units are located on different apparatuses.

23. The apparatus of claim 16, wherein two or more transmit power levels of two or more transmitter units are adjusted.

24. An apparatus for wireless communications, comprising:

means for identifying a first power level for a first transmitter unit; and

means for dynamically selecting at least one of a second power level or an active time period for a second transmitter unit based on the first power level, wherein a total power used by the first and the second transmitter units is less than or equal to an allowable power level which is determined based on a radio frequency (RF) exposure limit, and the first and the second transmitter units operate near simultaneously using one or more transmit antennas.

25. The apparatus of claim 24, wherein the means for dynamically selecting the second power level comprises:

means for selecting the second power level based on one or more of a regulatory radio frequency (RF) exposure limit, a target margin to the RF exposure limit and measured specific absorption limit (SAR) values for the first and the second transmitter units.

26. The apparatus of claim 24, wherein the means for dynamically selecting the active time period comprises:

means for selecting the active time period for the second transmitter unit to adjust an average transmit power of the second transmitter unit.

27. The apparatus of claim 24, further comprising:

means for selecting an active time period and a power level for the first transmitter unit to adjust an average transmit power of the first transmitter unit; and

means for adjusting the transmit power level of the first transmitter unit based on the selected active time period and the selected power level for the first transmitter unit.

28. The apparatus of claim 24, wherein the first and the second transmitter units are located on different apparatuses.

29. The apparatus of claim 24, further comprising:

means for determining priority of the first and the second transmitter units; and

means for maintaining at least one of power level or active time period of a transmitter unit that has a higher priority and adjusting power level or active time period of a transmitter unit with a lower priority.

30. An apparatus for wireless communications, comprising:

means for identifying a first power level for a first transmitter unit; and

means for dynamically selecting at least one of a second power level or an active time period for the first transmitter unit based on the first power level, wherein an average power used by the first transmitter unit for a period of time is less than or equal to an allowable power level which is determined based on at least one of a radio frequency (RF) exposure limit, a target margin to the RF exposure limit or a measured specific absorption limit (SAR) value for the first transmitter unit.

31. A computer-program product for wireless communications, comprising a computer readable medium having instructions stored thereon, the instructions being executable by one or more processors and the instructions comprising:

instructions for identifying a power level for a first transmitter unit;

instructions for selecting a power identifier for a second transmitter unit from one or more look-up tables based at least on the power level, wherein the first and the second transmitter units operate near simultaneously using one or more transmit antennas; and

instructions for adjusting transmit power levels of at least one of the first and the second transmitter units based on the power level and the power identifier, wherein the transmit power levels of the first and the second transmitter units are less than or equal to an allowable power level which is determined based on a radio frequency (RF) exposure limit.

32. A computer-program product for wireless communications, comprising a computer readable medium having instructions stored thereon, the instructions being executable by one or more processors and the instructions comprising:

instructions for identifying a first power level for a first transmitter unit; and

instructions for dynamically selecting at least one of a second power level or an active time period for a second transmitter unit based on the first power level, wherein a total power used by the first and the second transmitter units is less than or equal to an allowable power level which is determined based on a radio frequency (RF) exposure limit, and the first and the second transmitter units operate near simultaneously using one or more transmit antennas.

33. A computer-program product for wireless communications, comprising a computer readable medium having instructions stored thereon, the instructions being executable by one or more processors and the instructions comprising:

instructions for identifying a first power level for a first transmitter unit; and

instructions for dynamically selecting at least one of a second power level or an active time period for the first transmitter unit based on the first power level, wherein an average power used by the first transmitter unit for a period of time is less than or equal to an allowable power level which is determined based on at least one of a radio frequency (RF) exposure limit, a target margin to the RF exposure limit or a measured specific absorption limit (SAR) value for the first transmitter unit.

34. An apparatus for wireless communications, comprising at least one processor configured to:

identify a power level for a first transmitter unit;

select a power identifier for a second transmitter unit from one or more look-up tables based at least on the power level, wherein the first and the second transmitter units operate near simultaneously using one or more transmit antennas; and

adjust transmit power levels of at least one of the first and the second transmitter units based on the power level and the power identifier, wherein the transmit power levels of the first and the second transmitter units are less than or equal to an allowable power level which is determined based on a radio frequency (RF) exposure limit; and

a memory coupled to the at least one processor.

35. An apparatus for wireless communications, comprising at least one processor configured to:

identify a first power level for a first transmitter unit; and

dynamically select at least one of a second power level or an active time period for a second transmitter unit based on the first power level, wherein a total power used by the first and the second transmitter units is less than or equal to an allowable power level which is determined based on a radio frequency (RF) exposure limit, and the first and the second transmitter units operate near simultaneously using one or more transmit antennas; and

a memory coupled to the at least one processor.

36. An apparatus for wireless communications, comprising at least one processor configured to:

identify a first power level for a first transmitter unit; and

dynamically select at least one of a second power level or an active time period for the first transmitter unit based on the first power level, wherein an average power used by the first transmitter unit for a period of time is less than or equal to an allowable power level which is determined based on at least one of a radio frequency (RF) exposure limit, a target margin to the RF exposure limit or a measured specific absorption limit (SAR) value for the first transmitter unit; and

a memory coupled to the at least one processor.