Method and apparatus for controlling a TX power amplifier

• US 7,486,938 B2
• Filed: 01/31/2005
• Issued: 02/03/2009
• Est. Priority Date: 06/18/2004
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Huang, Shine C., Lin, Ping-Chun
• Primary Examiner(s): NGUYEN, SIMON
• Application Number:
  US11/047,032
• Publication Number:
  US 20050282508A1
• Time in Patent Office: 1,464 Days
• Field of Search: 4551142-1154, 4551271-1275
• US Class Current: 455/91
• CPC Class Codes: H03G 3/3047 for intermittent signals, e.g. burst signals
• CPC Class Codes: H04B 1/04 Circuits
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 2001/0416 having gain or transmission power control

Abstract

A method and an apparatus for controlling a TX power amplifier are provided in the present invention. The invention is applied for generating a power control curve in a power variation area to control the power variation for signal transmission when the TX power amplifier transmits the data during two continuous time slots, which are a first time slot and a second time slot, respectively have a first transmission power value K1 and a second transmission power value K2. The invention is aimed at producing a concave inter-ramp control curve in a inter-ramp division of the power variation area for controlling the power variation of the TX power amplifier, where the power for signal transmission is transformed from the first transmission power value K1 to the second transmission power value K2.

Claims

1. A method of controlling output power of a device in a multi-slot wireless communication system, comprising:

providing a first power value at a first time point in a first slot;

providing a second power value at a second time point in a second slot, wherein the second slot is adjacent to the first slot;

determining a first original curve section of an original power curve in accordance with the first slot;

determining a second original curve section of the original power curve in accordance with the second slot;

generating an output power curve according to the original power curve; and

adjusting the output power between the first time point and the second time point according to the output power curve, wherein at least one power value of the output power curve is substantially less than the first power value and the second power value.

2. The method of claim 1, wherein the first slot and the second slot respectively have a data area, a guard area is located between the data area of the first slot and the data area of the second slot, the output power curve is formed at the guard area.

3. The method of claim 1, wherein a difference between the first time point and the second time point is less than a slot time.

4. The method of claim 3, wherein the difference between the first time point and the second time point is less than a quarter of the slot time.

5. The method of claim 1, wherein the output power curve comprises a first portion FL′

(t) scaled into SL′

*FL(t) and a second portion FR′

(t) scaled into SR′

*FR(t), wherein FL(t)=the first original curve section, FR(t)=the second original curve section, SL′

=the first power value minus H, SR′

=the second power value minus H, and H is the lowest power value of the output power curve.

6. The method of claim 5, wherein SL′

is a function of 2^N1 and SR′

is a function of 2^N2, where N1 and N2 are each a positive integer.

7. The method of claim 1, wherein the at least one power value of the output power curve is approximately 0.

8. The method of claim 1, further comprising:

storing information of the original curve sections in a memory, wherein the information is used to generate the original curve sections.

9. The method of claim 1, wherein the original curve sections comprises polynomial functions.

10. The method of claim 1, wherein the output power curve comprises a concave curve.

11. The method of claim 1, wherein the output power curve comprises a nonlinear concave curve.

12. The method of claim 1, wherein the system comprises a TDMA communication system.

13. The method of claim 1, wherein the first power value in the first slot and the second power value in the second slot are different.

14. The method of claim 1, wherein the original power curve is divided horizontally into an original left section comprising the first original curve section and an original right section comprising the second original curve section.

15. The method of claim 14, wherein the original power curve is divided equally into said original left section and said original right section.

16. The method of claim 1, wherein generating the output power curve comprises:

generating a first portion of the output power curve in accordance with the first original curve section; and

generating a second portion of the output power curve in accordance with the second original curve section.

17. The method of claim 16, wherein:

generating the first portion of the output power curve comprises scaling the first original curve section in accordance with the first power value; and

generating the second portion of the output power curve comprises scaling the second original curve section in accordance with the second power value.

18. The method of claim 16, wherein:

generating the first portion of the output power curve comprises scaling the first original curve section in accordance with the first power value and a lowest power value between the first time point and the second time point; and

generating the second portion of the output power curve comprises scaling the second original curve section in accordance with the second power value and the lowest power value between the first time point and the second time point.

19. An apparatus for controlling output power of a device in a multi-slot wireless communication system, comprising:

a means for providing a first power value at a first time point in a first slot and a second power value at a second time point in a second slot, wherein the second slot is adjacent to the first slot;

a means for determining a first original curve section of an original power curve in accordance with the first slot and for determining a second original curve section of the original power curve in accordance with the second slot;

a means for generating an output power curve in accordance with the original power curve; and

a means for adjusting the output power between the first time point and the second time point according to the output power curve, wherein at least one power value of the output power curve is substantially less than the first power value and the second power value.

20. The apparatus of claim 19, wherein the first slot and the second slot respectively have a data area, a guard area is located between the data area of the first slot and the data area of the second slot, the output power curve is formed at the guard area.

21. The apparatus of claim 19, wherein a difference between the first time point and the second time point is less than a slot time.

22. The apparatus of claim 21, wherein the difference between the first time point and the second time point is less than a quarter of the slot time.

23. The apparatus of claim 19, wherein the output power curve comprises a first portion FL′

(t) scaled into SL′

*FL(t) and a second portion FR′

(t) scaled into SR′

*FR(t), wherein FL(t)=the first original curve section, FR(t)=the second original curve section, SL′

=the first power value minus H, SR′

=the second power value minus H, and H is the lowest power value of the output power curve.

24. The apparatus of claim 23, wherein SL′

is a function of 2^N1 and SR′

is a function of2^N2, where N1 and N2 are each a positive integer.

25. The apparatus of claim 19, wherein the at least one power value of the output power curve is approximately 0.

26. The apparatus of claim 19, further comprising:

a means for storing information of the original curve sections in a memory, wherein the information is used to generate the original curve sections.

27. The apparatus of claim 19, wherein the original curve sections comprises polynomial functions.

28. The apparatus of claim 19, wherein the output power curve comprises a concave curve.

29. The apparatus of claim 19, wherein the output power curve comprises a nonlinear concave curve.

30. The apparatus of claim 19, wherein the system comprises a TDMA communication system.

31. The apparatus of claim 19, wherein the first power value in the first slot and the second power value in the second slot are different.

32. The apparatus of claim 19, wherein the device comprises a transmission power amplifier of a mobile phone.

33. The apparatus of claim 19, wherein the apparatus comprises a coprocessor.

34. A mobile phone, comprising the apparatus of claim 19.

35. The apparatus of claim 19, wherein said means for generating the output power curve further comprises comprises:

means for generating a first portion of the output power curve in accordance with the first original curve section; and

means for generating a second portion of the output power curve in accordance with the first original curve section.

36. The apparatus of claim 35, wherein:

said means for generating the first portion of the output power curve comprises means for scaling the first original curve section in accordance with the first power value; and

said means for generating the second portion of the output power curve comprises means for scaling the second original curve section in accordance with the second power value.

37. The apparatus of claim 35, wherein:

said means for generating the first portion of the output power curve comprises means for scaling the first original curve section in accordance with the first power value and a lowest power value between the first time point and the second time point; and

said means for generating the second portion of the output power curve comprises means for scaling the second original curve section in accordance with the second power value and the lowest power value between the first time point and the second time point.