Passive system and method to equalize distortion in an RF satellite chain

• US 8,126,044 B2
• Filed: 10/25/2006
• Issued: 02/28/2012
• Est. Priority Date: 10/25/2006
• Status: Active Grant

• Current Assignee: DIRECTV, LLC (AT&T, Inc.)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Cavanagh, Eduardo
• Primary Examiner(s): Tran, Khanh C
• Assistant Examiner(s): Ghulamali, Qutbuddin
• Application Number:
  US11/586,383
• Publication Number:
  US 20080102751A1
• Time in Patent Office: 1,952 Days
• Field of Search: 375/229, 375/232, 375/233, 455/3.01, 455/3.02
• US Class Current: 375/232
• CPC Class Codes: H04B 17/391 Modelling the propagation channel
• CPC Class Codes: H04H 20/74 of satellite networks
• CPC Class Codes: H04L 2025/03445 Time domain
• CPC Class Codes: H04L 2025/03522 Frequency domain
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end

Abstract

A system and method for configuring an equalizer 48 for a transmission link includes a computer 82 that forms a mathematical model of an analog equalizer having a plurality of mathematical model filter stages. The computer 82 determines a desired response and tunes each of the plurality of mathematical model filter stages toward the desired response to form a plurality of model filter parameters to compensate for distortions in the transmission link. The equalizer 48 is coupled to the RF chain. The plurality of filter stages is tuned in response to the filter parameters. The RF signals are broadcast in response to analog equalizer.

Claims

1. A method of configuring an analog equalizer for a transmission link comprising:

forming a mathematical model of an analog equalizer having a plurality of mathematical model filter stages;

determining a desired response;

tuning each of the plurality of mathematical model filter stages toward the desired response to form a plurality of tuned filter parameters to compensate for distortions in the transmission link;

coupling an analog equalizer having a plurality of filter stages to an RF chain;

configuring the analog equalizer in response to the plurality of tuned filter parameters; and

broadcasting RF signals using the analog equalizer.

2. A method as recited in claim 1 wherein tuning each of the plurality of mathematical model filter stages comprises sequentially tuning each of the plurality of mathematical model filter stages.

3. A method as recited in claim 1 wherein tuning each of the plurality of mathematical model filter stages comprises iteratively tuning each of the plurality of mathematical model filter stages.

4. A method as recited in claim 3 wherein iteratively tuning each of the plurality of mathematical model filter stages comprises iteratively tuning using a non-linear least squares method.

5. A method as recited in claim 1 wherein the transmission link is an uplink.

6. A method as recited in claim 1 further comprising increasing a satellite transponder capacity by improving a signal-to-nose ratio in response to configuring.

7. A method as recited in claim 1 wherein determining a desired response comprises determining the desired response is determined in response to samples from a receiving device.

8. A method as recited in claim 7 wherein the receiving device comprising a satellite signal receiver.

9. A method as recited in claim 7 wherein the receiving device comprises an integrated receiver decoder.

10. A method as recited in claim 1 further comprising displaying the tuned filter parameters.

11. A method as recited in claim 1 wherein the plurality of tuned filter parameters comprises determining a sum of the mathematical filter stages.

12. A method as recited in claim 11 further comprising displaying the desired response and the sum of the mathematical filter stages.

13. A method as recited in claim 1 wherein displaying comprises displaying a frequency response.

14. A method as recited in claim 1 wherein displaying comprises displaying a group delay.

15. A system of equalizing an RF transmission chain including a transmission link comprising:

a computer having a mathematical model of an analog equalizer with a plurality of mathematical model filter stages stored therein, said computer determining a desired response and tuning each of the plurality of mathematical model filter stages toward the desired response to form a plurality of tuned filters parameter to compensate for distortions in the transmission link; and

analog equalizer having a plurality of filter stages, said analog equalizer coupled to the RF transmission chain for broadcasting signals and configured in response to the plurality of tuned filter parameters.

16. A system as recited in claim 15 wherein the computer sequentially tunes each of the plurality of mathematical model filter stages.

17. A system as recited in claim 15 wherein the computer tunes each of the plurality of mathematical model filter stages.

18. A system as recited in claim 15 wherein the computer iteratively tunes each of the plurality of mathematical model filter stages using a non-linear least squares system.

19. A system as recited in claim 15 wherein the computer determines a desired response in response to samples from a receiving device.

20. A system as recited in claim 19 wherein the receiving device comprising a satellite signal receiver.

21. A system as recited in claim 19 wherein the receiving device comprises an integrated receiver decoder.

22. A system as recited in claim 15 further comprising a display coupled to the computer displaying the tuned filter parameters.

23. A system as recited in claim 15 wherein the plurality of tuned filter parameters comprises determining a sum of the mathematical filter stages.

24. A system as recited in claim 15 further comprising a display coupled to the computer displaying the desired response and the sum of the mathematical filter stages.

25. A system as recited in claim 15 further comprising a display displaying a frequency response.

26. A system as recited in claim 15 further comprising a display coupled to the computer displaying a group delay.