Calimetrics, Inc.

Steve W McLaughlin

Terrence L Wong

Lloyd R Welch

David C Lee

Yung-Cheng Lo

Yi Ling

A system and method are disclosed for modulation encoding data for storage or transmission on a multilevel medium. The method includes encoding a first portion of data using a first tier modulation code. The first tier modulation code maps a first portion of the data onto a first set of symbols. A second portion of data is encoded using a second tier modulation code. The second tier modulation maps the second portion of the data onto a second set of symbols. The second tier modulation code has error correcting characteristics. A third set of symbols is determined based on the first set of symbols and the second set of symbols. The third set of symbols is suitable to determine nominal read signal levels from a multilevel medium. Improved error characteristics are realized for encoding data for storage or transmission on a multilevel medium.

Method and apparatus for modulation encoding data for storage on a multi-level optical recording medium

A method is disclosed for compensating for intersymbol interference on an optical disc. The method includes measuring an intersymbol linear transfer function. The intersymbol linear transfer function substantially describes a linear portion of the effect of intersymbol interference on an optically detected read signal from an optical disc. A partial response target frequency response is divided by the intersymbol linear transfer function to obtain a linear equalization filter response. A read signal from the optical disc is convolved with the linear equalization filter response. This results in the read signal being equalized and containing a controlled partial-response target intersymbol interference. There is also disclosed a method of compensating utilizing a decision feedback equalizer where the target frequency response is either a partial-response or a zero-forcing response.

Method for providing improved equalization for the reading of marks on optical data-storage media

Method and apparatus for modulation encoding data for storage on a

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Decatur, GA, United States of America

Steve W McLaughlin