DIGITAL AND ANALOG POWER CONTROL FOR AN OFDMA/CDMA ACCESS TERMINAL

• US 20080242337A1
• Filed: 03/25/2008
• Published: 10/02/2008
• Est. Priority Date: 03/26/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gore, Dhananjay Ashok, Sampath, Hemanth, Teague, Edward Harrison
• Granted Patent: US 8,095,166 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels

Abstract

Aspects describe controlling a power level for an access terminal in a wireless communication system that utilizes multiple modulation waveforms. The power can be controlled after an Access Grant is received in response to an Access Probe until the mobile device transitions into a steady state. A reference power can be continuously monitored and a setting of a power amplifier can be modified only when the reference power changes. A digital gain of a reverse data channel can be adjusted relative to the reference power level.

Claims

1. A method for providing power control for at least two modulation waveforms used in a wireless communication system, comprising:

setting a reference power level for a reverse link control channel of a first modulation waveform using open-loop power control and closed-loop power control;

adjusting a digital gain of a reverse link control channel of a second modulation waveform relative to the reference power level; and

adjusting a digital gain of a reverse link data channel of the second modulation waveform relative to the reference power level.

2. The method of claim 1, wherein setting the reference power level for the reverse link control channel of the first modulation waveform using open-loop power control, comprises:

utilizing a difference in mean received power from a reverse link serving sector during successive superframe preamble intervals.

3. The method of claim 1, wherein setting the reference power level for the reverse link control channel of the first modulation waveform using closed-loop power control, comprises:

utilizing erasure bits received from an access point to update the reference power level.

4. The method of claim 1, wherein setting the reference power level for the reverse link control channel of the first modulation waveform using closed-loop power control, comprising:

utilizing up-down power control bits received from an access point to update the reference power level.

5. The method of claim 1, wherein setting the reference power level for the reverse link control channel of the first modulation waveform using open-loop power control and closed-loop power control is given by P_CTRL=ProbePower+CtrlAccessOffset.

6. The method of claim 1, wherein the digital gain of the reverse link data channel of the second modulation waveform is adjusted by a factor proportional to a reverse link data channel gain.

7. The method of claim 6, wherein the digital gain of the reverse link data channel of the second modulation waveform is applied at a modulator block prior to an IFFT stage of a reverse link multiple modulation waveform transmitter.

8. The method of claim 1, wherein the digital gain of the reverse link control channel of the second modulation waveform is adjusted by a factor proportional to a reverse link control channel gain.

9. The method of claim 8, wherein the digital gain of the reverse link control channel of the second modulation waveform is applied at a modulator block prior to an IFFT stage of a reverse link multiple modulation waveform transmitter.

10. The method of claim 1, wherein the reference power level is updated by adjusting settings of a Power Amplifier, an Analog Front End, and a Digital-to-Analog Converter.

11. The method of claim 1, wherein the digital gain of the reverse link data channel of the second modulation waveform and the digital gain of the reverse link control channel of the second modulation waveform are power boosted if the reverse link control channel of the first modulation waveform is not present in a Reverse Link Transmission Frame.

12. The method of claim 1, wherein the digital gain of the reverse link data channel of the second modulation waveform and the digital gain of the reverse link control channel of the second modulation waveform are limited to a maximum pre-determined gain to mitigate generated interference within the wireless communication system.

13. The method of claim 1, further comprising:

transmitting an in-band or out-of band message that includes details on a maximum number of reverse link data-subcarriers that can be transmitted, wherein the maximum number of reverse link data-subcarriers is subject to Power Amplifier limitations and maximum pre-determined gain limitations.

14. A wireless communications apparatus, comprising:

a memory that retains instructions related to setting a reference power level for a reverse link control channel of a first modulation waveform using open-loop power control and closed-loop power control, adjusting a digital gain of a reverse link control channel of a second modulation waveform as a function of the reference power level, and adjusting a digital gain of a reverse link data channel of the second modulation waveform as a function of the reference power level; and

a processor, coupled to the memory, configured to execute the instructions retained in the memory.

15. The wireless communications apparatus of claim 14, the memory further retains instructions relating to utilizing a difference in mean received power from a reverse link serving sector during successive superframe preamble intervals.

16. The wireless communications apparatus of claim 14, the memory further retains instructions relating to utilizing erasure bits received from an access point to update the reference power level.

17. The wireless communications apparatus of claim 14, the memory further retains instructions relating to utilizing up-down power control bits received from an access point to update the reference power level.

18. The wireless communications apparatus of claim 14, wherein setting a reference power level for a reverse link control channel of the first modulation waveform using open-loop power control and closed-loop power control is given by P_CTRL=ProbePower+CtrlAccessOffset.

19. The wireless communications apparatus of claim 14, wherein the digital gain of the reverse link data channel of the second modulation waveform is adjusted by a factor proportional to a reverse link data channel gain.

20. The wireless communications apparatus of claim 19, wherein the digital gain of the reverse link data channel of the second modulation waveform is applied at a modulator block before an IFFT stage of a reverse link multi-modulation waveform transmitter.

21. The wireless communications apparatus of claim 14, wherein the digital gain of the reverse link control channel of the second modulation waveform is adjusted by a factor proportional to a reverse link control channel gain.

22. The wireless communications apparatus of claim 21, wherein the digital gain of the reverse link control channel of the second modulation waveform is applied at a modulator block before an IFFT stage of a reverse link multiple modulation waveform transmitter.

23. The wireless communications apparatus of claim 14, wherein the reference power level is updated by adjusting settings of a Power Amplifier, an Analog Front End, and a Digital-to-Analog Converter.

24. The wireless communications apparatus of claim 14, wherein the digital gain of the reverse link data channel of the second modulation waveform and the digital gain of the reverse link control channel of the second modulation waveform are power boosted if the reverse link control channel of the first modulation waveform channel is not present in a Reverse Link Transmission Frame.

25. The wireless communications apparatus of claim 14, wherein the digital gain of the reverse link data channel of the second modulation waveform and the digital gain of the reverse link control channel of the second modulation waveform are limited to a maximum pre-determined gain to mitigate generated interference within the wireless communication system.

26. The wireless communications apparatus of claim 14, the memory further retaining instructions relating to transmitting an in-band or out-of band message that includes details on a maximum number of reverse link data-subcarriers that can be transmitted, wherein the maximum number of reverse link data-subcarriers is subject to Power Amplifier limitations and maximum pre-determined gain limitations.

27. A wireless communications apparatus that facilitates power control, comprising:

means for setting a reference power level for a reverse link control channel of a first modulation waveform using open-loop power control and closed-loop power control;

means for adjusting a digital gain of a reverse link control channel of a second modulation waveform relative to the reference power level; and

means for changing a digital gain of a reverse link data channel of the second modulation waveform relative to the reference power level.

28. The wireless communications apparatus of claim 27, further comprising:

means for using a difference in mean received power from a reverse link serving sector during successive superframe preamble intervals.

29. The wireless communications apparatus of claim 27, further comprising:

means for using erasure bits received from an access point to update the reference power level.

30. The wireless communications apparatus of claim 27, further comprising:

means for utilizing up-down power control bits received from an access point to update the reference power level.

31. The wireless communications apparatus of claim 27, wherein the means for setting a reference power level for a reverse link control channel of the first modulation waveform using open-loop power control and closed-loop power control is given by P_CTRL=ProbePower+CtrlAccessOffset.

32. The wireless communications apparatus of claim 27, wherein the digital gain of the reverse link data channel of the second modulation waveform is adjusted by a factor proportional to a reverse link data channel gain.

33. The wireless communications apparatus of claim 27, wherein the digital gain of the reverse link control channel of the second modulation waveform is adjusted by a factor proportional to a reverse link control channel gain.

34. A machine-readable medium having stored thereon machine-executable instructions for:

transmitting an access probe;

determining a receive power from a single sector;

setting a reference power of a reverse link control channel of a first modulation waveform;

changing a digital gain of a reverse link control channel of a second modulation waveform as a function of the reference power; and

changing a digital gain of a reverse link data channel of the second modulation waveform as a function of the reference power.

35. The machine-readable medium of claim 34, the instructions further comprising:

monitoring the reference power;

determining if the reference power is different; and

changing a power amplifier setting if the reference power is different.

36. The machine-readable medium of claim 34, the instructions further comprising using at least one of an erasure based closed loop power-control or UpDown based closed-loop power control to set the reference power of the reverse link control channel of the first modulation waveform.

37. In a wireless communications system, an apparatus comprising:

a processor configured to;

set a reference power level for a reverse link control channel of a first modulation waveform using open-loop power control and closed-loop power control;

adjust a digital gain of a reverse link control channel of a second modulation waveform relative to the reference power level; and

adjust a digital gain of a reverse link data channel of the second modulation waveform relative to the reference power level.