Method and apparatus for controlling a TX power amplifier

• US 7,489,908 B2
• Filed: 05/06/2005
• Issued: 02/10/2009
• Est. Priority Date: 06/18/2004
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Lin, Ping-Chun, Huang, Shine C.
• Primary Examiner(s): NGUYEN, SIMON
• Application Number:
  US11/124,476
• Publication Number:
  US 20050282507A1
• Time in Patent Office: 1,376 Days
• Field of Search: 455/522, 455/67.11, 455/127.1, 455/115.1
• 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 reference power curve in accordance with the first slot;

determining a second reference power curve in accordance with the second slot;

generating an output power curve according to the first reference power curve and the second reference 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 output power value of the output power curve is substantially less than each of 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, and the method further comprises forming the output power curve at a guard area between the data area of the first slot and the data area of the second slot.

3. The method of claim 1, further comprising:

setting a difference between the first time point and the second time point to be less than a predetermined value.

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 a slot duration.

5. The method of claim 1, wherein the output power curve comprises a first portion and a second portion, and the method further comprises:

generating the first portion of the output power curve from the first reference power curve and the first power value; and

generating the second portion of the output power curve from the second reference power curve and the second power value.

6. The method of claim 5, wherein generating the first portion of the output power curve comprises performing a first mathematical operation on the first reference power curve and the first power value, and generating the second portion of the output power curve comprises performing a second mathematical operation on the second reference power curve and the second power value.

7. The method of claim 6, wherein the first mathematical operation comprises adding a predetermined power value to at least one of the first reference power curve and the first power value, and the second mathematical operation comprises adding the predetermined power value to at least one of the second reference power curve and the second power value.

8. The method of claim 7, wherein generating the first portion of the output power curve further comprises multiplying the first reference power curve and the first power value, and generating the second portion of the output power curve further comprises multiplying the second reference power curve and the second power value, wherein the first power value and/or and the second power value may have the predetermined power value added thereto.

9. The method of claim 1, wherein the first reference power curve is FL(t) and the second reference power curve is FR(t), and the output power curve comprises a first portion FL′

(t) and a second portion FR′

(t), wherein the output power curve is generated according to the following equations;

FL′

(t)=H+FL(t)*SL′

; and

FR′

(t)=H+FR(t)*SR′

;

wherein SL′

=SL−

H, SR′

=SR−

H, SL is the first power value, SR is the second power value, and H is a predetermined value.

10. The method of claim 9, wherein H is a minimum power value of the output power curve.

11. The method of claim 9, wherein H is about the output power value.

12. The method of claim 9, SL′

is 2^X, SR′

is 2^Y, and X and Y are integers.

13. The method of claim 1, wherein the output power value is approximately 0.

14. The method of claim 1, wherein the output power value is at least 6 dB less than a smaller of the first power value and the second power value.

15. The method of claim 1, further comprising:

storing control information in a database; and

generating the reference power curves from the control information.

16. The method of claim 15, wherein the reference power curves comprises a function:

[1+COS(2π

*n/N)]/2, where n and N are numerical parameter values from the control information.

17. The method of claim 1, wherein the reference power curves comprises polynomial functions.

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

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

20. The method of claim 1, wherein the system comprises a TDMA-compliant communication system.

21. The method of claim 1, wherein the system comprises an EDGE-compliant communication system.

22. The method of claim 21, wherein the first slot comprises a first modulation type and the second slot comprises a second modulation type different from the first modulation type.

23. A method of controlling a device output power 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;

generating an output power curve according to at least one reference power curve between the first time point and the second time point, wherein at least one output power value of the output power curve is substantially less than the first power value and the second power value, wherein the reference power curve comprises a first power curve FL(t) and a second power curve FR(t), and the output power curve comprises a first portion FL′

(t) and a second portion FR′

(t), wherein the output power curve is generated according to the following equations;

FL′

(t)=H+FL(t)*SL′

, and

FR′

(t)=H+FR(t)*SR′

;

wherein SL′

=SL−

H, SR′

=SR−

H, SL is the first power value, SR is the second power value, and H is a predetermined value; and

adjusting the output power according to the output power curve.

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

a measurement device configured to provide 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 reference curve generator configured to provide a first reference power curve in accordance with the first slot and a second reference power curve in accordance with the second slot;

an output curve generator configured to generate the output power curve according to the first reference power curve and the second reference power curve; and

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

25. The apparatus of claim 24, wherein the first slot and the second slot respectively have a data area, and the controller is further configured to form the output power curve at a guard area between the data area of the first slot and the data area of the second slot.

26. The apparatus of claim 24, wherein the controller is further configured to set a difference between the first time point and the second time point to be less than a predetermined time period.

27. The apparatus of claim 26, wherein the difference between the first time point and the second time point is less than a quarter of a slot duration.

28. The apparatus of claim 24, wherein the first reference power curve is FL(t) and a second reference power curve is FR(t), and the output power curve comprises a first portion FL′

(t) and a second portion FR′

(t), wherein the curve generator is further configured to generate the output power curve according to the following equations;

FL′

(t)=H+FL(t)*SL′

,and

FR′

(t)=H+FR(t)*SR′

;

wherein SL′

=SL−

H, SR′

=SR−

H, SL is the first power value, SR is the second power value, and H is a predetermined value.

29. The apparatus of claim 28, wherein H is a minimum power value of the output power curve.

30. The apparatus of claim 28, wherein H is about the output power value.

31. The apparatus of claim 24, wherein the output power value is approximately 0.

32. The apparatus of claim 24, wherein the output power value is at least 6 dB less than a smaller of the first power value and the second power value.

33. The apparatus of claim 24, wherein SL′

is 2^X, SR′

is 2^Y, and X and Y are integers.

34. The apparatus of claim 24, wherein the apparatus further comprises a memory or database configured to store control information for the reference power curves, and the reference curve generator is further configured to generate the reference power curve from the control information.

35. The apparatus of claim 34, wherein the reference curve generator generates the reference power curve according to:

[1+COS(2π

*n/N)]/2, where n and N are numerical parameter values from the control information.

36. The apparatus of claim 24, wherein the reference curve generator is further configured to generate the reference power curves from a polynomial function.

37. The apparatus of claim 24, wherein the output power curve comprises a concave curve.

38. The apparatus of claim 24, wherein the output power curve comprises a nonlinear concave curve.

39. A TDMA-compliant communication system, comprising the apparatus of claim 24.

40. An EDGE-compliant communication system, comprising the apparatus of claim 24.

41. The apparatus of claim 24, wherein the system comprises an EDGE-compliant communication system, the first slot comprises a first modulation type, and the second slot comprises a second modulation type different from the first modulation type.

42. The apparatus of claim 24, wherein the device further comprises a transmission power amplifier.

43. A mobile phone, comprising the apparatus of claim 24.

44. The mobile phone of claim 43, wherein the apparatus is part of an integrated circuit (IC).

45. An apparatus for controlling an 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 providing a first reference power curve in accordance with the first slot and a second reference power curve in accordance with the second slot;

a means for generating an output power curve according to the reference power curves between the first time point and the second time point, wherein at least one output power value of the output power curve is substantially less than the first power value and the second power value; and

a means for adjusting the output power according to the output power curve.

46. The apparatus of claim 45, wherein the reference power curves comprise polynomial functions.

47. The apparatus of claim 45, wherein the first reference power curve is FL(t) and the second reference power curve is FR(t), and the output power curve comprises a first portion FL′

(t) and a second portion FR′

(t), wherein the means for generating the output power curve generates the output power curve according to the following equation;

FL′

(t)=H+FL(t)*SL′

; and

FR′

(t)=H+FR(t)*SR′

;

wherein SL′

=SL−

H, SR′

=SR−

H, SL is the first power value, SR is the second power value, and H is a predetermined value.

48. A mobile phone, comprising the apparatus of claim 45 and a transmission power amplifier.

49. The mobile phone of claim 48, wherein the apparatus is part of an integrated circuit (IC).

50. A multi-slot wireless communication system, comprising:

a base station; and

a mobile unit configured to communicate with the base station by a plurality of slots, comprising;

a transmission power amplifier;

a measurement device configured to provide 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 database configured to provide a first reference power curve in accordance with the first slot and a second reference power curve in accordance with the second slot;

a curve generator, connected to the measurement device and the database, configured to generate an output power curve according to the reference power curves between the first time point and the second time point, wherein at least one output power value of the output power curve is substantially less than the first power value and the second power value; and

a controller, coupled to the curve generator and the transmission power amplifier, configured to adjust the output power of the transmission power amplifier according to the output power curve.

51. The multi-slot wireless communication system of claim 50, wherein the multi-slot wireless communication system is a TDMA-compliant communication system.

52. The multi-slot wireless communication system of claim 50, wherein the multi-slot wireless communication system is an EDGE-compliant communication system.

53. The multi-slot wireless communication system of claim 52, wherein the first slot has a first modulation type and the second slot has a second modulation type different from the first modulation type.