Interaction Between Maximum Power Reduction and Power Scaling in Wireless Networks

• US 20110319120A1
• Filed: 06/24/2011
• Published: 12/29/2011
• Est. Priority Date: 06/29/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chen, Wanshi, Luo, Tao, Gaal, Peter, Montojo, Juan
• Granted Patent: US 8,744,513 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/281 taking into account user or data type priority
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

Methods, apparatuses, and articles of manufacture are disclosed for adjusting a power level in connection with transmitting parallel uplink channels. In one aspect, a user equipment determines a power-limited condition in which a total transmit power of a group of power-controlled channels exceeds a maximum level in a transmission subframe. The user equipment may determine, in an iterative fashion, power backoff values by which to establish a configured maximum power level. The parallel uplink channels in the group may be prioritized and different backoff values may be used with channels having different priorities. The user equipment may thereafter adjust a transmit power of the power-controlled channels based on the configured maximum power level.

Claims

1. A method, comprising:

comparing a total transmit power of a plurality of power-controlled channels with a maximum power level, wherein the plurality of power-controlled channels is configured for parallel transmission in an uplink subframe;

determining a power backoff from the maximum power level when the total transmit power exceeds the maximum power level;

iterating the power backoff based at least in part on a priority of channels in the plurality of power-controlled channels; and

adjusting a transmit power of one or more channels in the plurality of power-controlled channels based on a result of iterating the power backoff.

2. The method of claim 1, wherein determining the power backoff comprises determining one or more data channel backoffs, and wherein the total transmit power is less than or equal to the maximum power level.

3. The method of claim 2, wherein iterating the power backoff comprises iterating the one or more data channel backoffs until a differential improvement in a performance metric is less than a predetermined value.

4. The method of claim 2, wherein iterating the power backoff comprises iterating the one or more data channel backoffs until a performance metric is determined to be less than a predetermined value.

5. The method of claim 2, wherein adjusting the transmit power comprises scaling the one or more data channels for transmission in relation to a power level corresponding to the last power backoff iteration.

6. The method of claim 1, wherein the power backoff is based on a performance metric associated with a power-frequency distribution of the plurality of power-controlled channels.

7. The method of claim 1, wherein control channels have a first priority, data channels with uplink control information (UCI) have a second priority and data channels without UCI have a third priority.

8. The method of claim 1, wherein the plurality of power-controlled channels comprises a control channel and a data channel in a single component carrier.

9. The method of claim 1, wherein the plurality of power-controlled channels comprises two or more control channels in two or more component carriers.

10. The method of claim 1, wherein the plurality of power-controlled channels comprises two or more data channels in two or more component carriers.

11. The method of claim 1, wherein the maximum power level comprises a first maximum power level for control channels and a second maximum power level for data channels, wherein the first and second maximum power levels are different power levels.

12. The method of claim 1, wherein the maximum power level comprises a same power level for data channels and control channels.

13. An apparatus, comprising:

a processor; and

a memory comprising processor executable instructions that, when executed by the processor, configures the apparatus as a user equipment (UE) to;

compare a total transmit power of a plurality of power-controlled channels with a maximum power level, wherein the plurality of power-controlled channels is configured for parallel transmission in an uplink subframe;

determine a power backoff from the maximum power level when the total transmit power exceeds the maximum power level;

iterate the power backoff based at least in part on a priority of channels in the plurality of power-controlled channels; and

adjust a transmit power of one or more channels in the plurality of power-controlled channels based on a result of iterating the power backoff.

14. The apparatus of claim 13, wherein to determine the power backoff, the apparatus is configured to determine one or more data channel backoffs, wherein the total transmit power is less than or equal to the maximum power level.

15. The apparatus of claim 14, wherein to iterate the power backoff, the machine is configured to iterate the one or more data channel backoffs until a differential improvement in a performance metric is less than a predetermined value.

16. The apparatus of claim 14, wherein to iterate the power backoff, the apparatus is configured to iterate the one or more data channel backoffs until a performance metric is determined to be less than a predetermined value.

17. The apparatus of claim 14, wherein to adjust the transmit power, the apparatus is configured to scale the one or more data channels for transmission according to the last power backoff iteration.

18. The apparatus of claim 13, wherein the power backoff is based on a performance metric associated with a power-frequency distribution of the plurality of power-controlled channels.

19. The apparatus of claim 13, wherein control channels have a first priority, data channels with uplink control information (UCI) have a second priority and data channels without UCI have a third priority.

20. The apparatus of claim 13, wherein the plurality of power-controlled channels comprises a control channel and a data channel in a single component carrier.

21. The apparatus of claim 13, wherein the plurality of power-controlled channels comprises two or more control channels in two or more component carriers.

22. The apparatus of claim 13, wherein the plurality of power-controlled channels comprises two or more data channels in two or more component carriers.

23. The apparatus of claim 13, wherein the maximum power level comprises a first maximum power level for control channels and a second maximum power level for data channels, wherein the first and second maximum power levels are different power levels.

24. An user equipment (UE) apparatus, comprising:

means for comparing a total transmit power of a plurality of power-controlled channels with a maximum power level, wherein the plurality of power-controlled channels is configured for parallel transmission in an uplink subframe;

means for determining a power backoff from the maximum power level when the total transmit power exceeds the maximum power level;

means for iterating the power backoff based at least in part on a priority of channels in the plurality of power-controlled channels; and

means for adjusting a transmit power of one or more channels in the plurality of power-controlled channels based on a result of iterating the power backoff.

25. The apparatus of claim 24, wherein the means for determining the power backoff comprises means for determining one or more data channel backoffs, wherein the total transmit power is less than or equal to the maximum power level.

26. The apparatus of claim 25, wherein the means for iterating the power backoff comprises means for iterating the one or more data channel backoffs until a differential improvement in a performance metric is less than a predetermined value.

27. The apparatus of claim 25, wherein the means for iterating the power backoff comprises means for iterating the one or more data channel backoffs until a performance metric is determined to be less than a predetermined value.

28. The apparatus of claim 25, wherein the means for adjusting the transmit power comprises means for scaling the one or more data channels for transmission in relation to a power level corresponding to the last power backoff iteration.

29. The apparatus of claim 24, wherein the power backoff is based on a performance metric associated with a power-frequency distribution of the plurality of power-controlled channels.

30. The apparatus of claim 24, wherein control channels have a first priority, data channels with uplink control information (UCI) have a second priority and data channels without UCI have a third priority.

31. The apparatus of claim 24, wherein the plurality of power-controlled channels comprises a control channel and a data channel in a single component carrier.

32. The apparatus of claim 24, wherein the plurality of power-controlled channels comprises two or more control channels in two or more component carriers.

33. The apparatus of claim 24, wherein the plurality of power-controlled channels comprises two or more data channels in two or more component carriers.

34. The apparatus of claim 24, wherein the maximum power level comprises a first maximum power level for control channels and a second maximum power level for data channels, wherein the first and second maximum power levels are different power levels.

35. The apparatus of claim 24, wherein the maximum power level comprises a same power level for data channels and control channels.

36. An article of manufacture, comprising a non-transitory machine-readable medium having instructions therein that, when executed by a machine, configure the machine as a user equipment (UE) to:

compare a total transmit power of a plurality of power-controlled channels with a maximum power level, wherein the plurality of power-controlled channels is configured for parallel transmission in an uplink subframe;

determine a power backoff from the maximum power level when the total transmit power exceeds the maximum power level;

iterate the power backoff based at least in part on a priority of channels in the plurality of power-controlled channels; and

adjust a transmit power of one or more channels in the plurality of power-controlled channels based on a result of iterating the power backoff.