Method and apparatus for obtaining coefficients of a fractionally-spaced equalizer
View Patent ↗A digital data recovery system for converting a suboptimal signal into a converted signal that closely approximates an original signal includes a first data filter, a first interpolator and a second interpolator. The first data filter filters the suboptimal signal to generate a first filtered signal. The first interpolator receives the first filtered signal and generates a first interpolated signal. Substantially concurrently, the second interpolator receives the suboptimal signal and generates a second interpolated signal. The digital data recovery system may further comprise a second data filter that receives the second interpolated signal and generates a second filtered signal. Further, the first data filter can include a set of first coefficients and the second data filter can include a set of second coefficients. Moreover, the second coefficients can be updated and subsequently transformed in order to update the first coefficients.
1. A digital data recovery system for converting a suboptimal signal into a converted signal that closely approximates an original signal, the digital data recovery system comprising:
a first data filter that filters the suboptimal signal to generate a first filtered signal;
a first interpolator that receives the first filtered signal and generates a first interpolated signal;
a second interpolator that receives the suboptimal signal and generates second interpolated signal.
2. The digital data recovery system of claim 1 further comprising a second data filter that receives the second interpolated signal and generates a second filtered signal.
3. The digital data recovery system of claim 2 further comprising a slicer that receives the first interpolated signal and generates a sliced signal.
4. The digital data recovery system of claim 3 further comprising a summing junction that compares the second filtered signal and the sliced signal and determines a path signal error based on the difference between the second filtered signal and the sliced signal.
5. The digital data recovery system of claim 4 wherein the first data filter includes a set of first coefficients and the second data filter includes a set of second coefficients, wherein the path signal error is utilized to update the second coefficients, and wherein the second coefficients are transformed to update the first coefficients.
6. The digital data recovery system of claim 2 further comprising a detector that receives the first interpolated signal and generates a detected signal.
7. The digital data recovery system of claim 6 further comprising a recover that receives the detected signal and generates a recoded signal.
8. The digital data recovery system of claim 7 further comprising a summing junction that compares the second filtered signal and the recoded signal and determines a path signal error based on the difference between the second filtered signal and the recoded signal.
9. The digital data recovery system of claim 8 wherein the first data filter includes a set of first coefficients and the second data filter includes a set of second coefficients, wherein the path signal error is utilized to update the second coefficients, and wherein the second coefficients are transformed to update the first coefficients.
10. The digital data recovery system of claim 2 wherein the first data filter includes a set of first coefficients and the second data filter includes a set of second coefficients, and wherein the second coefficients are transformed to update the first coefficients.
11. A media library including a storage medium and the digital data recovery system of claim 1 .
12. The media library of claim 11 wherein the media library is a tape library.
13. A media drive including the digital data recovery system of claim 1 .
14. The media drive of claim wherein the media drive is a tape drive.
15. A method for converting a suboptimal signal into a converted signal that closely approximates an original signal, the method comprising the steps of:
directing the suboptimal signal along a first path including a first data filter and a first interpolator; and
directing the suboptimal signal along a second path including a second data filter and a second interpolator, the second data filter being spaced apart from the first data filter.
16. The method of claim 15 wherein the suboptimal signal is directed along the second path substantially simultaneously with the suboptimal signal being directed along the first path.
17. The method of claim 15 wherein the suboptimal signal is directed to the first data filter prior to being directed to the first interpolator.
18. The method of claim 15 wherein the suboptimal signal is directed to the second interpolator prior to being directed to the second data filter.
19. The method of claim 15 wherein the step of directing the suboptimal signal along the first path includes the first data filter having a set of first coefficients, wherein the step of directing the suboptimal signal along the second path includes the second data filter having a set of second coefficients, and wherein the set of first coefficients are updated based at least in part on the set of second coefficients.
20. The method of claim 15 wherein the first path further includes a slicer, and further comprising the step of generating a sliced signal from the suboptimal signal by processing the suboptimal signal along the first path through the first data filter, the first interpolator and the slicer.
21. The method of claim 15 wherein the first path further includes a detector and a recoder, and further comprising the step of generating a recoded signal from the suboptimal signal by processing the suboptimal signal along the first path through the first data filter, the first interpolator, the detector and the recoder.
22. A method for converting a suboptimal signal into a converted signal that closely approximates an original signal, the method comprising the steps of:
directing the suboptimal signal along a first path including a first data filter, a first interpolator, and a slicer;
generating a sliced signal from the suboptimal signal by processing the suboptimal signal along the first path through the first data filter, the first interpolator and the slicer; and
directing the suboptimal signal along a second path including a second data filter and a second interpolator.
23. The method of claim 22 further comprising the step of generating a second filtered signal from the suboptimal signal by processing the suboptimal signal along the second path through the second interpolator and the second data filter.
24. The method of claim 23 further comprising the step of determining a path signal error in a summing junction based on the difference between the second filtered signal and the sliced signal.
25. The method of claim 24 wherein the step of directing the suboptimal signal along the first path includes the first data filter having a set of first coefficients, wherein the step of directing the suboptimal signal along the second path includes the second data filter having a set of second coefficients, and further comprising the steps of updating the second coefficients with the path signal error, transforming the updated second coefficients into a format that is compatible with the first coefficients in a coefficient transformer, and updating the first coefficients with the transformed second coefficients.
26. A method for converting a suboptimal signal into a converted signal that closely approximates an original signal, the method comprising the steps of:
directing the suboptimal signal along a first path including a first data filter, a first interpolator, a detector and a recoder;
generating a recoded signal from the suboptimal signal by processing the suboptimal signal along the first path through the first data filter, the first interpolator, the detector and the recoder; and
directing the suboptimal signal along a second path including a second data filter and a second interpolator.
27. The method of claim 26 further comprising the step of generating a second filtered signal from the suboptimal signal by processing the suboptimal signal along the second path through the second interpolator and the second data filter.
28. The method of claim 27 further comprising the step of determining a path signal error in a summing junction based on the difference between the second filtered signal and the recoded signal.
29. The method of claim 28 wherein the step of directing the suboptimal signal along the first path includes the first data filter having a set of first coefficients, wherein the step of directing the suboptimal signal along the second path includes the second data filter having a set of second coefficients, and further comprising the steps of updating the second coefficients with the path signal error, transforming the updated second coefficients into a format that is compatible with the first coefficients in a coefficient transformer, and updating the first coefficients with the transformed second coefficients.
30. A method for converting a suboptimal signal into a converted signal that closely approximates an original signal, the method comprising the steps of:
directing the suboptimal signal along a first path including a first data filter and a first interpolator, the first data filter having a set of first coefficients;
generating a first altered signal by processing the suboptimal signal along the first path through the first data filter and the first interpolator, the second data filter having a set of second coefficients;
directing the suboptimal signal along a second path including a second data filter and a second interpolator;
generating a second altered signal by processing the suboptimal signal along the second path through the second data filter and the second interpolator;
determining a path signal error in a summing junction based on the difference between the first altered signal and the second altered signal;
updating the second coefficients with the path signal error;
transforming the updated second coefficients into a format that is compatible with the first coefficients in a coefficient transformer; and
updating the first coefficients with the transformed second coefficients.
31. A method for converting a suboptimal signal into a converted signal that closely approximates an original signal, the method comprising the steps of:
directing the suboptimal signal along a first path including a first data filter and a first interpolator; and
directing the suboptimal signal along a second path including a second data filter and a second interpolator, the suboptimal signal being directed to the second interpolator prior to being directed to the second data filter.
32. A method for converting a suboptimal signal into a converted signal that closely approximates an original signal, the method comprising the steps of:
directing the suboptimal signal along a first path including a first data filter and a first interpolator, the first data filter having a set of first coefficients; and
directing the suboptimal signal along a second path including a second data filter and a second interpolator, the second data filter having a set of second coefficients, wherein the set of first coefficients are updated based at least in part on the set of second coefficients.