Method and apparatus for controlling a TX power amplifier

• US 7,489,909 B2
• Filed: 06/06/2005
• 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:
  US11/147,152
• Publication Number:
  US 20050281353A1
• Time in Patent Office: 1,345 Days
• Field of Search: 4551271-1275, 455/522, 370/337, 370/345, 370/347
• 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 2001/0416 having gain or transmission power control
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

A method and an apparatus for controlling a TX power amplifier are provided. The method is for generating a power control curve in an inter-slot region between two continuous or adjacent time slots, which respectively have different modulation types. The method and apparatus produces a concave inter-slot ramp control curve for reducing the power of the TX power amplifier in the inter-slot region, where the power for signal transmission is transformed from a first power value K1 to a second power value K2. The method and apparatus further estimates a transient period of the concave inter-slot ramp control curve, during which modulation switching of the TX power amplifier may occur.

Claims

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

providing a first power value in a first slot at a first time immediately before the inter-slot region;

providing a second power value in a second slot at a second time immediately after the inter-slot region, wherein the second slot is adjacent to the first slot and the second slot uses a different modulation type than the first slot;

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

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

configuring or generating an output power curve in the inter-slot region according to the original power curves, 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 output power curve comprises a first portion and a second portion, and the method further comprises:

generating a first portion of the output power curve from the first original power curve; and

generating a second portion of the output power curve from the second original power curve.

3. The method of claim 2, wherein generating the first portion of the output power curve comprises performing a first mathematical operation on the first original 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 original power curve and the second power value.

4. The method of claim 3, wherein the first mathematical operation comprises adding a predetermined power value to at least one of the first original 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 original power curve and the second power value.

5. The method of claim 4, wherein generating the first portion of the output power curve further comprises multiplying the first original power curve and the first power value, and generating the second portion of the output power curve further comprises multiplying the second original 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.

6. The method of claim 4, wherein the predetermined power value is below a threshold value.

7. The method of claim 6, wherein the threshold value is at least 6 dBm less than a smaller of the first power value and the second power value.

8. The method of claim 2, wherein:

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

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

9. The method of claim 2, wherein:

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

10. The method of claim 1, further comprising:

storing control information in a memory, and

generating the original power curves from the control information.

11. The method of claim 10, wherein each of the original power curves comprises a function:

[1+COS(2π

*n/N)]/2,

where n and N are numerical values from the control information.

12. The method of claim 1, wherein the original power curves comprise polynomial functions.

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

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

15. The method of claim 14, wherein the first slot comprises one of a 8PSK and a GMSK modulation type and the second slot comprises the other of the 8PSK and the GMSK modulation type.

16. An apparatus for controlling output power in an inter-slot region of a multi-slot wireless communication device, comprising:

a device configured to provide (i) a first power value in a first slot at a first time immediately before the inter-slot region and (ii) a second power value in a second slot at a second time immediately after the inter-slot region, wherein the second slot is adjacent to the first slot and the second slot uses a different modulation type than the first slot;

an output curve generator configured to determine a first original power curve in accordance with the first slot, determine a second original power curve in accordance with the second slot, and configure or generate an output power curve according to the original power curves; and

a controller configured to adjust the output power in the inter-slot region 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.

17. The apparatus of claim 16, further comprising a memory configured to provide the original power curves.

18. The apparatus of claim 17, wherein the memory further stores control information for the original power curves.

19. The apparatus of claim 18, further comprising an original curve generator configured to generate the original power curves according to:

[1+COS(2π

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

20. The apparatus of claim 17, wherein the original power curves comprise polynomial functions.

21. The apparatus of claim 16, wherein the output power curve comprises a concave curve.

22. An EDGE-compliant communication system, comprising the apparatus of claim 16.

23. The apparatus of claim 16, wherein the system comprises an EDGE-compliant communication system, the first slot comprises one of an 8PSK or a GMSK modulation type, and the second slot comprises the other of the 8PSK or GMSK modulation type.

24. The apparatus of claim 16, wherein the device further comprises a transmission power amplifier.

25. A mobile phone, comprising the apparatus of claim 16.

26. The mobile phone of claim 25, wherein the apparatus is part of an integrated circuit (IC) therein.

27. The apparatus of claim 16, wherein the output curve generator is further configured to:

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

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

28. The apparatus of claim 27, wherein the output curve generator is further configured to:

scale the first original power curve in accordance with the first power value to generate the first portion of the output power curve; and

scale the second original power curve in accordance with the second power value to generate the second portion of the output power curve.

29. The apparatus of claim 27, wherein the output curve generator is further configured to:

scale the first original power curve in accordance with the first power value and a lowest power value between the first time point and the second time point to generate the first portion of the output power curve; and

scale the second original power curve in accordance with the second power value and the lowest power value between the first time point and the second time point to generate the second portion of the output power curve.

30. 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 device configured to provide (i) a first power value in a first slot at a first time immediately before an inter-slot region and (ii) a second power value in a second slot at a second time immediately after the inter-slot region, wherein the second slot is adjacent to the first slot and the second slot uses a different modulation type than the first slot;

a memory configured to provide a first original power curve in accordance with the first slot and a second original power curve in accordance with the second slot;

a curve generator, connected to the measurement device and the memory, configured to generate an output power curve in the inter-slot region according to the original power curves, 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.

31. The multi-slot wireless communication system of claim 30, wherein the multi-slot wireless communication system is an EDGE-compliant communication system.

32. The multi-slot wireless communication system of claim 31, wherein the first slot has one of an 8PSK and a GMSK modulation type and the second slot has the other of the 8PSK and GMSK modulation type.

33. The multi-slot wireless communication system of claim 30, wherein the curve generator is further configured to:

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

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

34. The multi-slot wireless communication system of claim 33, wherein the curve generator is further configured to:

scale the first original power curve in accordance with the first power value to generate the first portion of the output power curve; and

scale the second original power curve in accordance with the second power value to generate the second portion of the output power curve.

35. The multi-slot wireless communication system of claim 33, wherein the curve generator is further configured to:

scale the first original power curve in accordance with the first power value and a lowest power value between the first time point and the second time point to generate the first portion of the output power curve; and

scale the second original power curve in accordance with the second power value and the lowest power value between the first time point and the second time point to generate the second portion of the output power curve.

36. A method of controlling output power in an inter-slot region of a multi-slot wireless communication device, comprising:

providing a first power value in a first slot at a first time immediately before the inter-slot region;

providing a second power value in a second slot at a second time immediately after the inter-slot region, wherein the second slot is adjacent to the first slot and the second slot uses a different modulation type than the first slot;

generating a first portion of an output power curve from a first original power curve, wherein generating the first portion of the output power curve comprises performing a first mathematical operation on the first original power curve and the first power value and the first mathematical operation comprises adding a predetermined power value to at least one of the first original power curve and the first power value;

generating a second portion of the output power curve from a second original power curve, wherein generating the second portion of the output power curve comprises performing a second mathematical operation on the second original power curve and the second power value and the second mathematical operation comprises adding the predetermined power value to at least one of the second original power curve and the second power value; and

adjusting said an output power in the inter-slot region 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.