Method for producing a transmission signal

• US 20050152472A1
• Filed: 05/14/2003
• Published: 07/14/2005
• Est. Priority Date: 05/14/2002
• Status: Active Grant

• Current Assignee: Callahan Cellular LLC (Intellectual Ventures LLC), Phenomix Corporation
• Original Assignee: Prasendt Investments LLC (Intellectual Ventures LLC)
• Inventors: Langer, Andreas, Irscheid, Otmar, Menge, Michael
• Granted Patent: US 7,672,397 B2
• Time in Patent Office: Days
• US Class Current: 375/297
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence

Abstract

A method for producing a transmission signal, wherein an input signal (Vd(t)), which is to be amplified, is fed to a power amplifier (PA) which outputs the signal in an amplified form (va(t)). A reproduction thereof is made and allocates a specific pre-distortion input signal (vd(t)) value to a specific input signal (vd(t)) value. A corresponding pre-distortion value is then determined for the input signal (vd(t)) and the corresponding pre-distortion value is applied to the input signal (vd(t)) in order to feed the pre-distorted input signal to the power amplifier (PA). Subsequently, the crest factor (CF) is calculated from the output signal (vd(t)) of the power (PA) and the reproduction or the value thereof if the determined crest factor departs from a predetermined range of values.

Claims

1-11. -11. (canceled)

12. A method for producing a transmission signal, wherein an input signal to be amplified is fed to a power amplifier which outputs the signal as an amplified output signal, the method comprising:

making a reproduction which allocates a pre-distortion input signal value to a value of the input signal;

determining a corresponding pre-distortion value for the input signal via the reproduction;

applying the pre-distortion value to the input signal and feeding a resulting pre-distorted input signal to the power amplifier;

determining a crest factor from the amplified output signal of the power amplifier; and

adapting the reproduction if the determined crest factor is not in a predetermined range.

13. A method for producing a transmission signal as claimed in claim 12, wherein adapting the reproduction comprises:

recalculating the values of the reproduction;

renewing application of the pre-distortion value to the input signal;

re-determining the crest factor from the amplified output signal of the power amplifier; and

repeating the steps of recalculating, renewing and re-determining until the determined crest factor is in the predetermined range.

14. A method for producing a transmission signal as claimed in claim 12, wherein the crest factor is determined using digital signal processing equipment.

15. A method for producing a transmission signal as claimed in claim 14, wherein the amplified output signal of the power amplifier is demodulated incoherently.

16. A method for producing a transmission signal as claimed in claim 15, wherein the amplified output signal of the power amplifier is digitized after being incoherently demodulated and routed to the digital signal processing equipment.

17. A method for producing a transmission signal as claimed in claim 15, wherein the amplified output signal is incoherently demodulated using an envelope-curve detector.

18. A circuit for producing a transmission signal, comprising:

a power amplifier having an input for accepting an input signal which is to be amplified and which is outputted at an output of the power amplifier as an amplified output signal;

equipment for making a reproduction which allocates a pre-distortion input signal value to a value of the input signal;

equipment for determining a pre-distortion value for the input signal and for applying the pre-distortion value to the input signal;

determining equipment for determining a crest factor from the amplified output signal of the power amplifier; and

adaptation equipment for adapting the reproduction if the determined crest factor is not in a predetermined range.

19. A circuit for producing a transmission signal as claimed in claim 18, wherein the determining equipment includes digital signal processing equipment for determining the crest factor.

20. A circuit for producing a transmission signal as claimed in claim 19, further comprising an envelope-curve detector for incoherently demodulating the output signal of the power amplifier.

21. A circuit for producing a transmission signal as claimed in claim 19, further comprising an analog-to-digital converter for digitizing the demodulated amplified output signal of the power amplifier to route the demodulated amplified output signal to the digital signal processing equipment.

22. A mobile telephone, comprising a circuit for producing a transmission signal wherein the circuit further comprises:

a power amplifier having an input for accepting an input signal which is to be amplified and which is outputted at an output of the power amplifier as an amplified output signal;

equipment for making a reproduction which allocates a pre-distortion input signal value to a value of the input signal;

equipment for determining a pre-distortion value for the input signal and for applying the pre-distortion value to the input signal;

determining equipment for determining a crest factor from the amplified output signal of the power amplifier; and

adaptation equipment for adapting the reproduction if the determined crest factor is not in a predetermined range.