Apparatus and method providing non-linear adaptive signal tracking

• US 20080123770A1
• Filed: 03/24/2006
• Published: 05/29/2008
• Est. Priority Date: 03/24/2006
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Copeland, Gregory Clark
• Granted Patent: US 7,782,974 B2
• Time in Patent Office: Days
• US Class Current: 375/285
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H03F 1/3258 based on polynomial terms
• CPC Class Codes: H03F 2200/321 Use of a microprocessor in an amplifier circuit or its control circuit
• CPC Class Codes: H03F 2201/3209 the amplifier comprising means for compensating memory effects
• CPC Class Codes: H03F 2201/3233 Adaptive predistortion using lookup table, e.g. memory, RAM, ROM, LUT, to generate the predistortion
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end

Abstract

An apparatus providing additional response for a distortion correcting device that receives a first signal at a correcting input and provides a first delayed output signal at an output includes: (a) A first signal combiner coupled with an input and the correcting input. (b) A delay unit coupled with the input provides a second delayed signal to a delayed signal terminal. (c) A second signal combiner coupled with the delayed signal terminal and the output employs the output signal and the second delayed signal to present an error signal at a first error terminal. (d) An adaptive circuit coupled with the input locus, the first signal combiner and the second signal combiner employs provides a supplemental signal to the first signal combiner which employs the input signal and the supplemental signal to present the first signal to reduce the error signal.

Claims

1. An apparatus providing non-linear adaptive signal tracking;

the apparatus receiving a first signal at a device input locus for a non-linear device and providing an output signal at a device output locus of said non-linear device;

the apparatus comprising;

(a) a first signal combining unit coupled with an input locus and with said device input locus;

(b) a second signal combining unit coupled with said device output locus;

said second signal combining unit employing said output signal and a first reference signal to present a difference signal at a first difference indicating terminal; and

(c) an adaptive circuit coupled with said first difference indicating terminal and said first signal combining unit;

said adaptive circuit employing said difference signal to present a correcting signal to said first signal combining unit;

said first signal combining unit employing said input signal and said correcting signal to present said first signal to said device input locus;

said correcting signal being appropriate to reduce said difference signal.

2. An apparatus providing non-linear adaptive signal tracking as recited in claim 1 wherein said adaptive circuit further employs a second reference signal to present said correcting signal to said first signal combining unit.

3. An apparatus providing non-linear adaptive signal tracking as recited in claim 1 wherein said first reference signal represents a desired output signal.

4. An apparatus providing non-linear adaptive signal tracking as recited in claim 2 wherein said first reference signal represents a desired output signal and wherein said second reference signal represents at least one factor affecting performance of said non-linear device.

5. An apparatus providing non-linear adaptive signal tracking as recited in claim 2 wherein said second reference signal is a weighted combination of a plurality of parametric signals;

each respective parametric signal of said plurality of parametric signals representing a respective performance response of said non-linear device.

6. An apparatus providing non-linear adaptive signal tracking as recited in claim 4 wherein said second reference signal is a weighted combination of a plurality of parametric signals;

each respective parametric signal of said plurality of parametric signals representing a respective performance response of said non-linear device.

7. An apparatus providing additional response for an error correcting device;

said error correcting device receiving a first signal at a correcting input locus and providing an output signal at an output locus;

said output signal being delayed with respect to said first signal by a first delay interval;

the apparatus comprising;

(a) a first signal combining unit coupled with an input locus and with said correcting input locus;

(b) a delay unit coupled with said input locus;

said delay unit receiving an input signal from said input locus and providing a delayed input signal to a first delayed signal terminal;

said delayed input signal being delayed with respect to said input signal by a second delay interval;

said second delay interval being substantially equal to said first delay interval;

(c) a second signal combining unit coupled with said first delayed signal terminal and with said output locus;

said second signal combining unit employing said output signal and said delayed input signal to present an error signal at a first error indicating terminal; and

(d) at least one adaptive circuit coupled with said input locus, said first signal combining unit and said second signal combining unit;

said at least one adaptive circuit employing a feedback signal related with said error signal and said input signal to present a supplemental correcting signal to said first signal combining unit;

said first signal combining unit employing said input signal said supplemental correcting signal to present said first signal to said correcting input locus;

said supplemental correcting signal being appropriate to reduce said error signal.

8. An apparatus supplementing response of a distortion correcting device as recited in claim 7 wherein said at least one adaptive circuit includes at least one adjustable signal approximating unit coupled with said input locus and said error indicating terminal;

said at least one signal approximating unit treating said error signal and said input signal to present an adjusting signal;

said adjusting signal being related to said correcting signal.

9. An apparatus supplementing response of a distortion correcting device as recited in claim 8 wherein said at least one adaptive circuit further includes a third signal combining unit coupled with said error indicating terminal and with said at least one signal approximating unit, said third signal combining unit and said at least one signal approximating unit cooperating to present a revised error signal for use by said at least one signal approximating unit in presenting said adjusting signal.

10. An apparatus supplementing response of a distortion correcting device as recited in claim 8 wherein said at least one signal approximating unit is an additive signal approximating unit.

11. An apparatus supplementing response of a distortion correcting device as recited in claim 9 wherein said at least one signal approximating unit is an additive signal approximating unit.

12. An apparatus supplementing response of a distortion correcting device as recited in claim 8 wherein said at least one adaptive circuit further includes a third signal combining unit coupled with said error indicating terminal and a fourth signal combining unit coupled with said third signal combining unit;

said third and fourth signal combining units each being coupled with said at least one signal approximating unit;

said third signal combining unit and said at least one signal approximating unit cooperating with a second delay unit to present a first-revised error signal including an imposed delay;

said fourth signal combining unit and said at least one signal approximating unit cooperating with a third delay unit to present a second-revised error signal without said imposed delay;

said at least one signal approximating unit treating said second-revised error signal and said input signal to present an adjusting signal;

said adjusting signal being related to said correcting signal.

13. An apparatus supplementing response of a distortion correcting device as recited in claim 12 wherein said at least one signal approximating unit is an additive signal approximating unit.

14. A method for providing additional response for an error correcting device;

said error correcting device receiving a first signal at a correcting input locus and providing an output signal at an output locus;

said output signal being delayed with respect to said first signal by a first delay interval;

the method comprising the steps of;

(a) in no particular order;

(1) providing a first signal combining unit coupled with an input locus and with said correcting input locus;

(2) providing a delay unit coupled with said input locus;

(3) providing a second signal combining unit coupled with said first delay unit and with said output locus; and

(4) providing at least one adaptive circuit coupled with said input locus, said first signal combining unit and said second signal combining unit;

(b) operating said delay unit to receive an input signal from said input locus and provide a delayed input signal to a first delayed signal terminal;

said delayed input signal being delayed with respect to said input signal by a second delay interval;

said second delay interval being substantially equal to said first delay interval;

(c) operating said second signal combining unit to employ said output signal and said delayed input signal to present an error signal at a first error indicating terminal; and

(d) operating said at least one adaptive circuit to employ a feedback signal related with said error signal and said input signal to present a supplemental correcting signal to said first signal combining unit;

said first signal combining unit employing said input signal and said supplemental correcting signal to present said first signal to said correcting input locus;

said supplemental correcting signal being appropriate to reduce said error signal.

15. A method for providing additional response for an error correcting device as recited in claim 14 wherein said at least one adaptive circuit includes at least one adjustable signal approximating unit coupled with said input locus and said error indicating terminal;

said at least one signal approximating unit treating said error signal and said input signal to present an adjusting signal;

said adjusting signal being related to said correcting signal.

16. A method for providing additional response for an error correcting device as recited in claim 15 wherein said at least one adaptive circuit further includes a third signal combining unit coupled with said error indicating terminal and with said at least one signal approximating unit, said third signal combining unit and said at least one signal approximating unit cooperating to present a revised error signal for use by said at least one signal approximating unit in presenting said adjusting signal.

17. A method for providing additional response for an error correcting device as recited in claim 15 wherein said at least one signal approximating unit is an additive signal approximating unit.

18. A method for providing additional response for an error correcting device as recited in claim 16 wherein said at least one signal approximating unit is an additive signal approximating unit.

19. A method for providing additional response for an error correcting device as recited in claim 15 wherein said at least one adaptive circuit further includes a third signal combining unit coupled with said error indicating terminal and a fourth signal combining unit coupled with said third signal combining unit;

said third and fourth signal combining units each being coupled with said at least one signal approximating unit;

said third signal combining unit and said at least one signal approximating unit cooperating with a second delay unit to present a first-revised error signal including an imposed delay;

said fourth signal combining unit and said at least one signal approximating unit cooperating with a third delay unit to present a second-revised error signal without said imposed delay;

said at least one signal approximating unit treating said second-revised error signal and said input signal to present an adjusting signal;

said adjusting signal being related to said correcting signal.

20. A method for providing additional response for an error correcting device as recited in claim 19 wherein said at least one signal approximating unit is an additive signal approximating unit.