Title:
SIGNAL PROCESSING METHOD AND REPRODUCING DEVICE USING THE SAME
Document Type and Number:
Japanese Patent JP3231405
Kind Code:
B2
Abstract:
PURPOSE: To automatically perform waveform equalization according to signal quality by finding an equalization error from a delay signal, a difference signal, and a ternary decision signal generated from an output signal, and feeding it back to an equalization constant for weighting.
CONSTITUTION: Three signals having the time difference T of delay signals B, C, and D are obtained for the reproduced signal A of the evaluation pattern of a recording medium through equalization delay element trams 31a-31c. Subtracters 32a and 32b multiply them by the equalization constant for weight and an adder subtracter 33 substrates the result from an equalized delay signal C to obtain an equalized waveform output signal E. Delay elements 41a and 41b obtain Yn and Yn-1 from a sampled value Yn+1 of the signal E with delay signals G and F and a difference signal J is obtained from an adder subtracter 42. For Yn, a ternary decision unit 43 obtains Xn of '+1, 0, -1' and obtains Xn-2 through FFs 41a and 41b, and a multiplier 45 finds a signal I. A multiplier 46 calculates a specific equalization constant K from the signals J and I. The constant K is held at a holding part 48 and the attenuation quantities (weighting of attenuators 32a and 32b are varied with a control signal. Consequently, a highly precise equalized waveform corresponding to the signal quality is obtained.
Inventors:
Hiroshi Mutoh
Application Number:
JP19720392A
Publication Date:
November 19, 2001
Filing Date:
July 23, 1992
Export Citation:
Assignee:
富士通株式会社
International Classes:
G11B5/09; G11B20/10; H03H15/00; H03H17/00; H03H21/00; H04B3/04; (IPC1-7): G11B5/09; G11B20/10; H03H15/00; H03H21/00; H04B3/04
Attorney, Agent or Firm:
Tadahiko Ito