Granted Patent B1

US 9,013,821 · App. 14/301,326 · Granted Apr 21, 2015

Abstract

Claims (57)

1. A data storage device comprising:

a disk comprising a plurality of data tracks;

a head actuated over the disk, the head comprising a plurality of read elements including a first read element and a second read element; and

control circuitry configured to:

read a first data track using the first read element to generate a first read signal;

sample the first read signal to generate first signal samples;

read a second data track adjacent the first data track using the second read element to generate a second read signal;

sample the second read signal to generate second signal samples;

process the first signal samples and the second signal samples using a first two-dimensional (2D) to one-dimensional (1D) equalizer to generate a first 1D sequence of equalized samples;

process the first signal samples and the second signal samples using a 2D-to-2D equalizer to generate a 2D sequence of equalized samples;

process the first 1D sequence of equalized samples using a first 1D detector to detect a first estimated data sequence; and

process the 2D sequence of equalized samples using a 2D detector to detect a second estimated data sequence.

2. The data storage device as recited in claim 1 , wherein the second read element is wider than the first read element.

3. The data storage device as recited in claim 1 , wherein:

the first 1D detector is configured to generate first probability metrics associated with the first estimated data sequence; and

the 2D detector is configured to process the first probability metrics to detect the second estimated data sequence.

4. The data storage device as recited in claim 3 , wherein:

the 2D detector is configured to generate second probability metrics associated with the second estimated data sequence; and

the first 1D detector is configured to process the second probability metrics to detect the first estimated data sequence.

5. The data storage device as recited in claim 4 , wherein the first 1D detector and the 2D detector are configured to iterate on the probability metrics at least once.

6. The data storage device as recited in claim 4 , wherein the first probability metrics and the second probability metrics are substantially uncorrelated.

7. The data storage device as recited in claim 1 , wherein:

the first 1D detector comprises a trellis type detector; and

the 2D detector comprises a trellis type detector.

8. The data storage device as recited in claim 1 , wherein the head comprises a third read element and the control circuitry is further configured to:

read a third data track adjacent the second data track using the third read element to generate a third read signal;

sample the third read signal to generate third signal samples;

process the third signal samples and the second signal samples using a second 2D-to-1D equalizer to generate a second 1D sequence of equalized samples;

process the first signal samples, the second signal samples, and the third signal samples using the 2D-to-2D equalizer to generate the 2D sequence of equalized samples; and

process the second 1D sequence of equalized samples using a second 1D detector to detect a third estimated data sequence.

9. A method of operating a data storage device, the method comprising:

reading a first data track using a first read element to generate a first read signal;

sampling the first read signal to generate first signal samples;

reading a second data track adjacent the first data track using a second read element to generate a second read signal;

sampling the second read signal to generate second signal samples;

processing the first signal samples and the second signal samples using a first two-dimensional (2D) to one-dimensional (1D) equalizer to generate a first 1D sequence of equalized samples;

processing the first signal samples and the second signal samples using a 2D-to-2D equalizer to generate a 2D sequence of equalized samples;

processing the first 1D sequence of equalized samples using a first 1D detector to detect a first estimated data sequence; and

processing the 2D sequence of equalized samples using a 2D detector to detect a second estimated data sequence.

10. The method as recited in claim 9 , wherein the second read element is wider than the first read element.

11. The method as recited in claim 9 , further comprising:

the first 1D detector generating first probability metrics associated with the first estimated data sequence; and

the 2D detector processing the first probability metrics to detect the second estimated data sequence.

12. The method as recited in claim 11 , further comprising:

the 2D detector generating second probability metrics associated with the second estimated data sequence; and

the first 1D detector processing the second probability metrics to detect the first estimated data sequence.

13. The method as recited in claim 12 , further comprising the first 1D detector and the 2D detector iterating on the probability metrics at least once.

14. The method as recited in claim 12 , wherein the first probability metrics and the second probability metrics are substantially uncorrelated.

15. The method as recited in claim 9 , wherein:

the first 1D detector comprises a trellis type detector; and

the 2D detector comprises a trellis type detector.

16. The method as recited in claim 9 , further comprising:

reading a third data track adjacent the second data track using a third read element to generate a third read signal;

sampling the third read signal to generate third signal samples;

processing the third signal samples and the second signal samples using a second 2D-to-1D equalizer to generate a second 1D sequence of equalized samples;

processing the first signal samples, the second signal samples, and the third signal samples using the 2D-to-2D equalizer to generate the 2D sequence of equalized samples; and

processing the second 1D sequence of equalized samples using a second 1D detector to detect a third estimated data sequence.

Assignments (7)