Recording and/or reproducing apparatus and method with asignal quality determining device and method

• US 20050128916A1
• Filed: 11/10/2004
• Published: 06/16/2005
• Est. Priority Date: 11/11/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Jae-wook, Shim, Jae-seong, Park, Hyun-soo, Lee, Jung-hyun, Cho, Eing-seob, Ryu, Eun-jin
• Granted Patent: US 7,477,584 B2
• Time in Patent Office: Days
• US Class Current: 369/59.210
• CPC Class Codes: G11B 19/04 Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
• CPC Class Codes: G11B 20/10009 Improvement or modification of read or write signals
• CPC Class Codes: G11B 20/10046 filtering or equalising, e.g. setting the tap weights of an FIR filter
• CPC Class Codes: G11B 20/10296 using the Viterbi algorithm
• CPC Class Codes: G11B 7/0901 for track following only G11B7/0925, G11B7/094, G11B7/0941, G11B7/0943, G11B7/0945, G11B7/0946, G11B7/0948 take precedence
• CPC Class Codes: G11B 7/0908 for focusing only G11B7/0925, G11B7/094, G11B7/0941, G11B7/0943, G11B7/0945, G11B7/0946, G11B7/0948 take precedence
• CPC Class Codes: G11B 7/0941 Methods and circuits for servo gain or phase compensation during operation for initialising servos G11B7/0945
• CPC Class Codes: G11B 7/0945 Methods for initialising servos, start-up sequences
• CPC Class Codes: G11B 7/0956 to compensate for tilt, skew, warp or inclination of the disc, i.e. maintain the optical axis at right angles to the disc

Abstract

A recording and/or reproducing apparatus and method with signal quality determining device and a method thereof, with the signal quality determining device including a signal estimator determining a level corresponding to a sample value of the RF signal using binary data obtained from the RF signal and generating a selection signal corresponding to the determined level, a channel identifier classifying the sample value into a plurality of levels according to the selection signal and obtaining an average value of the sample values classified into each level, and a quality calculator outputting a signal quality value representing quality of the RF signal using each sample value output from the channel identifier and the average value of the sample values classified into each level. Accordingly, quality of an RF signal can be determined more exactly, and focus compensation, tilt compensation, detrack compensation, and recording signal optimization can be performed using the determined signal quality.

Claims

1. An RF signal quality determining device, comprising:

a signal estimator determining a level, corresponding to a sample value of an input RF signal, using binary data obtained from the RF signal and generating a selection signal corresponding to the determined level;

a channel identifier classifying the sample value into a plurality of levels, according to the selection signal, and obtaining an average value of sample values classified into each level; and

a quality calculator calculating a signal quality value representing a signal quality of the RF signal using each sample value output from the channel identifier and the average value of the sample values classified into each level.

2. The device of claim 1, wherein the channel identifier comprises a plurality of averaging filters receiving respective sample values classified into respective levels and obtaining an average value of the sample values classified into each level.

3. The device of claim 2, wherein the averaging filters comprise a lowpass filter.

4. The device of claim 1, wherein the signal quality value is a signal to noise ratio (SNR) calculated using each sample value and the average value of the sample values classified into each level.

5. The device of claim 1, wherein the signal quality value is an absolute SNR (ASNR) calculated using each sample value and the average value of the sample values classified into each level.

6. The device of claim 1, wherein the signal quality value is a peak ASNR (PASNR) calculated using each sample value and the average value of the sample values classified into each level.

7. The device of claim 1, wherein the binary data is obtained by viterbi decoding the RF signal.

25. A recording and/or reproducing apparatus, comprising:

a signal detection unit to generate an RF signal representative of information of a medium;

the RF signal quality determining device of claim 1;

and

a processing unit to record and/or reproduce information to/from the medium.

26. The apparatus of claim 25, further comprising a processor performing at least one of focus compensation, tilt compensation, detrack compensation, and/or recording signal optimization, based on the signal quality value.

8. A method of determining a signal quality of an input RF signal, the method comprising:

determining a level, corresponding to a sample value of the RF signal, using binary data obtained from the RF signal and generating a selection signal corresponding to the determined level;

classifying the sample value into a plurality of levels, according to the selection signal, and obtaining an average value of sample values classified into each level; and

calculating a signal quality value representing the signal quality of the RF signal using each sample value and the average value of the sample values classified into each level.

9. The method of claim 8, wherein the signal quality value is an SNR calculated using each sample value and the average value of the sample values classified into each level.

10. The method of claim 8, wherein the signal quality value is an ASNR calculated using each sample value and the average value of the sample values classified into each level.

11. The method of claim 8, wherein the signal quality value is a PASNR calculated using each sample value and the average value of the sample values classified into each level.

12. The method of claim 8, wherein the binary data is obtained by viterbi decoding the RF signal.

29. A method of recording and/or reproducing information to/from a medium, comprising:

generating an RF signal representative of information of the medium;

determining a signal quality of an input RF signal using the RF signal quality determining method of claim 8;

and

recording and/or reproducing information to/from the medium.

30. The method of claim 29, further comprising performing at least one of focus compensation, tilt compensation, detrack compensation, and/or recording signal optimization, based on the signal quality value.

31. The method of claim 29, wherein the signal quality value is an ASNR calculated using only absolute values of each sample value and the average value of the sample values classified into each level.

13. An RF signal quality determining device, comprising:

a signal estimator receiving binary data of an RF signal and estimating a value of the RF signal; and

a quality calculator receiving the estimated value of the RF signal and the RF signal and calculating a signal quality value representing a signal quality of the RF signal.

14. The device of claim 13, wherein the signal estimator comprises a predetermined type of finite impulse response (FIR) filter.

15. The device of claim 13, wherein the signal quality value is an SNR calculated using the estimated value of the RF signal and the RF signal.

16. The device of claim 13, wherein the signal quality value is an ASNR calculated using the estimated value of the RF signal and the RF signal.

17. The device of claim 13, wherein the signal quality value is a PASNR calculated using the estimated value of the RF signal and the RF signal.

18. The device of claim 13, wherein the binary data is obtained by viterbi decoding the RF signal.

27. A recording and/or reproducing apparatus, comprising:

a signal detection unit to generate an RF signal representative of information of a medium;

the RF signal quality determining device of claim 13;

and

a processing unit to record and/or reproduce information to/from the medium.

28. The apparatus of claim 27, further comprising a processor performing at least one of focus compensation, tilt compensation, detrack compensation, and/or recording signal optimization, based on the signal quality value.

19. A method of determining a signal quality of an RF signal, the method comprising:

obtaining an estimated value of the RF signal using binary data of the RF signal; and

calculating a signal quality value representing the signal quality of the RF signal using the estimated value of the RF signal and the RF signal.

20. The method of claim 19, wherein the obtaining of the estimated value of the RF signal comprises obtaining the estimated value of the RF signal using a predetermined type of FIR filter.

21. The method of claim 19, wherein the signal quality value is an SNR calculated using the estimated value of the RF signal and the RF signal.

22. The method of claim 19, wherein the signal quality value is an ASNR calculated using the estimated value of the RF signal and the RF signal.

23. The method of claim 19, wherein the signal quality value is a PASNR calculated using the estimated value of the RF signal and the RF signal.

24. The method of claim 19, wherein the binary data is obtained by viterbi decoding the RF signal.

32. A method of recording and/or reproducing information to/from a medium, comprising:

generating an RF signal representative of information of the medium;

determining a signal quality of an input RF signal using the RF signal quality determining method of claim 19;

and

recording and/or reproducing information to/from the medium.

33. The method of claim 32, further comprising performing at least one of focus compensation, tilt compensation, detrack compensation, and/or recording signal optimization, based on the signal quality value.

34. The method of claim 32, wherein the signal quality value is an ASNR calculated using only absolute values of each sample value and the average value of the sample values classified into each level.