Systems and methods for sector quality determination in a data processing system
The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for data set quality determination.
1. A data processing system, the data processing system comprising:
a data decoder circuit operable to apply a data decode algorithm to a decoder input derived from a data set to yield a decoded output, wherein the decoded output includes an unsatisfied check, and soft data associated with the unsatisfied check; and
a quality metric calculation circuit operable to calculate a quality metric corresponding to the data set using the soft data using the soft data to calculate a contribution from each variable node associated with the unsatisfied check to yield a local metric.
2. The system of claim 1 , wherein the system further comprises:
a data detector circuit operable to apply a data detection algorithm to the data set to yield a detected output, wherein the decoder input is derived from the detected output.
3. The system of claim 2 , wherein the data detector circuit is selected from a group consisting of: a Viterbi algorithm data detector circuit, and a maximum a posteriori data detector circuit.
4. The system of claim 1 , wherein the local metric is a first local metric, wherein the unsatisfied check is a first unsatisfied check, and wherein calculating the quality metric corresponding to the data set further comprises:
using the soft data to calculate a contribution from each variable node associated with a second unsatisfied check to yield a second local metric; and
summing a first interim metric derived from the first local metric and a second interim metric derived form the second local metric to yield the quality metric.
5. The system of claim 4 , wherein the quality metric calculation circuit is further operable to:
normalize the first local metric to a number of variable nodes corresponding the first unsatisfied check to yield the first interim metric; and
normalize the second local metric to a number of variable nodes corresponding the second unsatisfied check to yield the second interim metric.
6. The system of claim 1 , wherein the quality metric is a first quality metric; wherein the unsatisfied check is a first unsatisfied check; wherein the data set is a first data set, wherein the decoder input is a first decoder input; wherein the decoded output is a first decoded output; wherein the data decoder circuit is further operable to apply the data decode algorithm to a second decoder input derived from a second data set to yield a second decoded output; wherein the second decoded output includes a second unsatisfied check, and soft data associated with the second unsatisfied check; wherein the quality metric calculation circuit is further operable to calculate a second quality metric corresponding to the second data set using the soft data associated with the second unsatisfied check.
7. The system of claim 6 , wherein the system further comprises:
an input buffer operable to store the first data set and the second data set; and
a scheduling circuit operable to select one of the first data set and the second data set for processing based at least in part on a comparison of the first quality metric and the second quality metric.
8. The system of claim 1 , wherein the data decoder circuit is a low density parity check decoder circuit.
9. The system of claim 1 , wherein the system is implemented as an integrated circuit.
10. The system of claim 1 , wherein the system is incorporated in a device selected from a group consisting of: a storage device, and a data transmission device.
11. A method for data set quality determination, the method comprising:
applying a data decode algorithm by a data decoder circuit to a decoder input derived from a data set to yield a decoded output, wherein the decoded output includes an unsatisfied check, and soft data associated with the unsatisfied check; and
calculating a quality metric for the data set based at least in part on the soft data using the soft data to calculate a contribution from each variable node associated with the unsatisfied check to yield a local metric.
12. The method of claim 11 , the method further comprising:
applying a data detection algorithm to the data set to yield a detected output, wherein the decoder input is derived from the detected output.
13. The method of claim 11 , wherein the local metric is a first local metric, wherein the unsatisfied check is a first unsatisfied check, and wherein calculating the quality metric corresponding to the data set further comprises: using the soft data to calculate a contribution from each variable node associated with a second unsatisfied check to yield a second local metric; and summing a first interim metric derived from the first local metric and a second interim metric derived from the second local metric to yield the quality metric.
14. The method of claim 13 , wherein calculating the quality metric further comprises:
normalizing the first local metric to a number of variable nodes corresponding the first unsatisfied check to yield the first interim metric; and
normalizing the second local metric to a number of variable nodes corresponding the second unsatisfied check to yield the second interim metric.
15. The method of claim 11 , wherein the quality metric is a first quality metric; wherein the unsatisfied check is a first unsatisfied check; wherein the data set is a first data set, wherein the decoder input is a first decoder input; wherein the decoded output is a first decoded output; and wherein the method further comprises:
applying the data decode algorithm to a second decoder input derived from a second data set to yield a second decoded output, wherein the second decoded output includes a second unsatisfied check, and soft data associated with the second unsatisfied check; and
calculating a second quality metric for the second data set based at least in part on the soft data associated with the second unsatisfied check.
16. The method of claim 11 , wherein the method further comprises:
selecting the data set for additional processing based at least in part on the quality metric.
17. A storage device, the storage device comprising:
a storage medium;
a head assembly disposed in relation to the storage medium and operable to provide a sensed signal corresponding to information on the storage medium;
a read channel circuit including:
an analog to digital converter circuit operable to sample an analog signal derived from the sensed signal to yield a series of digital samples;
an equalizer circuit operable to equalize the digital samples to yield a data set;
a data decoder circuit operable to apply a data decode algorithm to a decoder input derived from the data set to yield a decoded output, wherein the decoded output includes an unsatisfied check, and soft data associated with the unsatisfied check; and
a quality metric calculation circuit operable to calculate a quality metric corresponding to the data set using the soft data using the soft data to calculate a contribution from each variable node associated with the unsatisfied check to yield a local metric.
18. The storage device of claim 17 , wherein the local metric is a first local metric, wherein the unsatisfied check is a first unsatisfied check, and wherein calculating the quality metric corresponding to the data set further comprises:
using the soft data to calculate a contribution from each variable node associated with a second unsatisfied check to yield a second local metric; and
summing a first interim metric derived from the first local metric and a second interim metric derived form the second local metric to yield the quality metric.
19. The storage device of claim 18 , wherein the quality metric calculation circuit is further operable to:
normalize the first local metric to a number of variable nodes corresponding the first unsatisfied check to yield the first interim metric; and
normalize the second local metric to a number of variable nodes corresponding the second unsatisfied check to yield the second interim metric.
20. The storage device of claim 17 , wherein the quality metric is a first quality metric; wherein the unsatisfied check is a first unsatisfied check; wherein the data set is a first data set, wherein the decoder input is a first decoder input; wherein the decoded output is a first decoded output; wherein the data decoder circuit is further operable to apply the data decode algorithm to a second decoder input derived from a second data set to yield a second decoded output; wherein the second decoded output includes a second unsatisfied check, and soft data associated with the second unsatisfied check; wherein the quality metric calculation circuit is further operable to calculate a second quality metric corresponding to the second data set using the soft data associated with the second unsatisfied check.