Data modulating method and apparatus, data demodulating method and apparatus, and code arranging method

• US 7,876,241 B2
• Filed: 11/21/2007
• Issued: 01/25/2011
• Est. Priority Date: 09/27/2002
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Jin-han, Shim, Jae-seong, Jung, Kiu-hae
• Primary Examiner(s): YOUNG, BRIAN K
• Application Number:
  US11/944,084
• Publication Number:
  US 20080068232A1
• Time in Patent Office: 1,161 Days
• Field of Search: 341/58, 341/59, 341/102, 341/103, 375/240
• US Class Current: 341/59
• CPC Class Codes: G11B 20/1426 conversion to or from block codes or representations thereof
• CPC Class Codes: H03M 5/145 Conversion to or from block codes or representations thereof

Abstract

In a data demodulating method and apparatus, and a code arranging method, a multiplexer multiplexes an input data stream divided by a predetermined length into a plurality of types of pseudo-random data streams using multiplexed information of predetermined bits by applying a predetermined multiplexing method to each of the pseudo-random data streams. An encoder RLL-modulates the plurality of types of pseudo-random data streams to create a modulated code stream including a minimum of DC components. The multiplexer generates the random data streams by inconsecutively scrambling the input data stream using the multiplexed information. The encoder weak DC-free RLL-modulates each of the multiplexed data streams without using a DC control sub code conversion table to which additional bits are added and provides a code stream including a minimum of DC components among multiplexed, RLL-modulated code streams.

Claims

1. An apparatus for processing data recorded on a recording layer in an information storage medium, the apparatus comprising:

a data modulator configured to perform a modulation operation of source data into a modulated code stream of code words where a minimum run length limit is confined to “

d” and

a maximum run length limit is confined to “

k”

, “

d” and

“

k”

being positive integers; and

a optical pickup configured to emit a light to the information storage medium to transfer data with respect to the information storage medium,

wherein the modulation operation comprises changing at least one of a code word A and a code word B into another code word such that a sum of an endzero of the code word A and a leadzero of a code word B is greater than or equal to the minimum run length limit and is less than or equal to the maximum run length limit when the code word B is connected to a code word A, the code word A being a preceding code word,

wherein the endzero is a number of successive zeros from least significant bits (LSBs) of the code word A to most significant bits (MSBs), and

wherein the leadzero is a number of successive zeros from most significant bits (MSBs) of the code word B to least significant bits (LSBs).

2. The apparatus of claim 1, wherein:

the minimum run length limit “

d”

is 1;

the maximum run length limit “

k”

is 7; and

the changing comprises changing the code word A into a code word in which the least significant bit (LSB) of the code word is “

0”

when the endzero of the code word A is “

0” and

the leadzero of the code word B is “

0”

.

3. The apparatus of claim 1, wherein the code words are subsequently demodulated by:

demodulating each n bit of input codewords into m-bit, where n≧

m, and m and n are positive integers, of a demodulation code unit configured to generate a non-inverted data stream having a predetermined length; and

inconsecutively descrambling the non-inverted data stream using multiplexed information to generate an inverted data stream.

4. The apparatus of claim 2, wherein the descrambling of the non-inverted data stream comprises:

performing an exclusive OR operation on a first demodulation code unit and initial data that is the multiplexed information to generate first inverted data;

outputting a second demodulation code unit to a q-1^th demodulation code unit without performing an exclusive OR operation;

performing an exclusive OR operation on the first demodulation code unit and a first q^th demodulation code unit of inconsecutive q^th demodulation code units to generate next inverted data; and

repeating an exclusive OR operation to the final one of the remaining q^th demodulation code units of the non-inverted data stream to provide the inverted data stream.

5. The apparatus of claim 1, wherein changing at least one of a code word A and a code word B into another code word comprises changing least significant bits (LSBs) of the code word A or most significant bits (MSBs) of the code word B.