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Information estimation method, information recording/reproducing equipment, information reproducing equipment and information recordingmedium

A technology for signal evaluation and recording media, applied in optical recording/reproduction, digital recording/reproduction, digital signal error detection/correction, etc. It can solve the problems of inability to evaluate signal quality and inability to accurately estimate error rate, etc.

Inactive Publication Date: 2008-10-01
KK TOSHIBA +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In doing so, the error rate cannot be accurately estimated, and the signal quality cannot be assessed

Method used

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  • Information estimation method, information recording/reproducing equipment, information reproducing equipment and information recordingmedium
  • Information estimation method, information recording/reproducing equipment, information reproducing equipment and information recordingmedium
  • Information estimation method, information recording/reproducing equipment, information reproducing equipment and information recordingmedium

Examples

Experimental program
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Effect test

Embodiment 1

[0065] Fig. 3 is a block diagram showing the configuration of one embodiment of the present invention. Referring to FIG. 3, an optical head device (PUH) 102 reads out information recorded on an information recording medium (optical disc) 101 as marks and spaces, obtaining a weak analog signal. Amplifier 103 amplifies the weak analog signal to a sufficiently high level. An analog-to-digital (AD) converter 104 converts the amplified analog signal into a digital reproduction signal. The equalizer 105 equalizes the digital reproduced signal so that the digital reproduced signal has a waveform corresponding to the PR characteristic to be used (hereinafter, the digital reproduced signal having such a waveform is simply referred to as "equalized signal"). Then, this equalized signal is sent to the Viterbi decoder 106 and the evaluation value calculator 107 . Viterbi decoder 106 decodes the equalized signal according to the Viterbi algorithm to obtain binary identification data. Th...

Embodiment 2

[0093] FIG. 5 shows a waveform adjustment circuit that uses the above-mentioned estimated value or an intermediate calculation result for calculating the estimated value. In FIG. 5, the same reference numerals as in FIG. 3 denote similar or corresponding structural elements. In the system shown in FIG. 5, the recording waveform generator 301 adjusts the recording parameters in such a manner that the evaluation value or the intermediate calculation result satisfies a predetermined value. The adjusted recording data is sent to the optical head device 102 .

[0094] A description will be given of how to adjust the recording parameters with reference to the reference tables shown in Tables (1-1) and (1-2) and using the mean values ​​and standard deviations calculated for each group. We assume the mean to be μ and the standard deviation to be σ. In this case, the larger the value of Z (=μ / σ), the lower the probability that the pattern T will be mistaken for the pattern F. Theref...

Embodiment 3

[0097] 6 and 7 show third and fourth embodiments of the present invention. Before describing the embodiment shown in FIG. 7, the embodiment shown in FIG. 6 will be described. Referring to FIG. 6, an optical head device (PUH) 102 reads out information recorded on an information recording medium (optical disc) 101 as marks and spaces, obtaining a weak analog signal. Amplifier 103 amplifies the weak analog signal to a sufficiently high level. An analog-to-digital (AD) converter 104 converts the amplified analog signal into a digital reproduction signal. The equalizer 105 equalizes the digital reproduction signal so that the digital reproduction signal has a waveform corresponding to the PR characteristic to be used. Then, the equalized signal is sent to the Viterbi decoder 106 , the first evaluation value calculator 107 and the second evaluation value calculator 108 .

[0098] Viterbi decoder 106 decodes the equalized signal according to the Viterbi algorithm to obtain binary ...

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PUM

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Abstract

Reproduction signals include patterns for which recognition errors are likely. With respect to such patterns, probable error patterns are prepared. Tables showing correct patterns and error patterns are prepared, and evaluation values accurately representing signal quality are calculated. In an apparatus using a PRML method, discrimination data and a plurality of predetermined bit sequence pairs are examined to detect matching. A bit sequence and corresponding two ideal responses are calculated. Euclidean distances between the two ideal responses and equalization signals are obtained, and the difference between the Euclidean distances is further obtained. A quality evaluation value of a reproduction signal is calculated based on a mean value, a standard deviation, an appearance probability of the predetermined bit sequence, and a Hamming distance between the predetermined bit sequence pairs.

Description

technical field [0001] The present invention relates to a signal evaluation method for evaluating a signal reproduced from an information recording medium, an information recording / reproducing apparatus, and an information recording medium. More specifically, the present invention relates to improvements in an evaluation device and evaluation method for reproducing a signal from an information recording medium and evaluating the reproduced signal. Background technique [0002] As a signal processing procedure performed by an information recording / reproducing apparatus, a PRML (Partial Response and Maximum Likelihood) discrimination method is known in the technical field. [0003] KOKAI Japanese Patent Application Publication No. 2002-358738 discloses a technique for evaluating signal quality in a system employing the PRML authentication method. [0004] According to the technique publicly disclosed by KOKAI, a differential metric distribution is prepared. Based on the assu...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G11B20/10G11B20/18G11B7/005H03M13/39
CPCG11B20/10111G11B20/10055G11B20/10009G11B7/0062G11B20/10101G11B20/1816
Inventor 柏原裕长井裕士大久保修一小川雅嗣中野正规岩永敏明
Owner KK TOSHIBA
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