Claims
- 1. A method for improving the quality of a digital signal evaluated by a digital decision circuit that produces an output signal and an error signal, the digital signal including a pilot for carrier recovery, the method comprising:
applying the digital signal to a feed forward filter (FFF) to produce a partially compensated signal; applying the output signal to a decision feedback filter (DFF); adjusting coefficients of the DFF responsive to the error signal; adjusting coefficients of the FFF responsive to the error signal; forming a DC offset signal representative of the coefficients of the DFF; modifying the DC offset signal with a signal representative of the pilot; forming a feedback signal by combining the output of the DFF and the modified DC offset signal; and combining the feedback signal and the partially compensated signal to form an input signal; and applying the input signal to the decision circuit.
- 2. The method of claim 1, additionally comprising modifying the input signal with the signal representative of the pilot before application of the input signal to the decision circuit.
- 3. The method of claim 2, in which the digital singal is in twos-complement format.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 10/184,384, filed Jun. 27, 2002, which is a continuation of application Ser. No. 09/794,724, filed Feb. 27, 2001 (now U.S. Pat. No. 6,438,164), which is a continuation of application Ser. No. 09/433,731, filed Nov. 3, 1999 (now U.S. Pat. No. 6,226,323), which claimed the benefit of the priority date of U.S. Provisional Application Serial Nos. 60/106,921, filed Nov. 3, 1998, 60/106,922, filed Nov. 3, 1998, 60/106,923, filed Nov. 3, 1998, 60/106,938, filed Nov. 3, 1998, 60/107,103, filed Nov. 4, 1998 and 60/107,037, filed Nov. 3, 1998, the entire disclosures of which are expressly incorporated herein by reference.
Provisional Applications (6)
|
Number |
Date |
Country |
|
60106921 |
Nov 1998 |
US |
|
60106922 |
Nov 1998 |
US |
|
60106923 |
Nov 1998 |
US |
|
60106938 |
Nov 1998 |
US |
|
60107103 |
Nov 1998 |
US |
|
60107037 |
Nov 1998 |
US |
Continuations (3)
|
Number |
Date |
Country |
Parent |
10184384 |
Jun 2002 |
US |
Child |
10830827 |
Apr 2004 |
US |
Parent |
09794724 |
Feb 2001 |
US |
Child |
10184384 |
Jun 2002 |
US |
Parent |
09433731 |
Nov 1999 |
US |
Child |
09794724 |
Feb 2001 |
US |