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US 7,142,135 B1Granted
Modulation methods and systems
AssigneeMedia Tek Inc.
InventorsHsin-Cheng Chen, Pi-Hai Liu, Ming-Yang Chao
Life of this patent
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Abstract
In a high-density optical storage system, data words are modulated into code words in a manner of minimizing the fluctuation of the digital sum value (DSV). A cumulative DSV is calculated for each possible value of a DSV control bit. The DSV control bit is determined to minimize the absolute cumulative DSV when detecting at least one subsequent DSV control bit or after a predetermined delay. A corresponding code word is generated according to the determined current DSV control bit.
Claims42
A modulation system, comprising:
- an encoder, transferring data words to tentative code words;
- a DSV control bit generator, determining the value of a DSV control bit according to the data words or the tentative code words to optimize the cumulative DSVs corresponding possible tentative code words, wherein the DSV control bit generator determines the value of a current DSV control bit which minimizes the absolute cumulative DSV when at least a subsequent DSV control bit is detected or after a predetermined delay;
- and
- a final code word generator, generating final code words according to the determined DSV control bit and the tentative code words.
1 more element
A modulation system, comprising:
- an encoder, transferring data words to tentative code words;
- a partial DSV generator, generating partial digital sum values (DSVs) according to the data words or tentative code words;
- a DSV accumulator, cumulating the partial DSVs as cumulative DSVs for possible values of a DSV control bit;
- a DSV control bit generator, determining the value of a DSV control bit according to the cumulative DSVs, wherein the DSV control bit generator determines the value of a current DSV control bit which minimizes the absolute cumulative DSV when at least a subsequent DSV control bit is detected or after a predetermined delay;
- and
- a final code word generator, generating final code words according to the determined DSV control bit and the tentative code words.
3 more elements
A modulation system, comprising:
- a data word to partial DSV transferring circuit, generating partial DSVs according to data words;
- a DSV accumulator, cumulating the partial DSVs as cumulative DSVs for possible values of a DSV control bit;
- a DSV control bit generator, determining the value of a DSV control bit according to the cumulative DSVs, wherein the DSV control bit generator determines the of a current DSV control bit which minimizes the absolute cumulative DSV when at least a subsequent DSV control bit is detected or after a predetermined delay;
- a final data word generator, generating a final data word according to the result of the DSV control bit and the data word;
- and
- an encoder to transfer the final data words to final code words.
3 more elements
A modulation system, comprising:
- a partial DSV generator, generating partial DSVs of code words corresponding to data words;
- a DSV accumulator, for cumulating partial DSVs as cumulative DSVs;
- a DSV control bit generator, determining the value of a DSV control bit according to the cumulative DSVs, wherein the DSV control bit generator determines the value of a current DSV control bit which minimizes the absolute cumulative DSV when at least a subsequent DSV control bit is detected or after a predetermined delay;
- and
- a DSV control bit buffer, storing the result of the determined DSV control bit.
2 more elements
A modulation system, comprising:
- a partial DSV generator, generating partial DSVs of code words corresponding to data words;
- a DSV accumulator, cumulating partial DSVs as cumulative DSVs;
- a DSV control bit generator, determining the value of a DSV control bit according to the cumulative DSVs, wherein the DSV control bit generator determines the value of a current DSV control bit which minimizes the absolute cumulative DSV when at least a subsequent DSV control bit is detected or after a predetermined delay;
- and
- a data word buffer, buffering a plurality of data words.
2 more elements
A modulation method, comprising the steps of:
- modulating a plurality of data words into a plurality of tentative code words by performing code conversion and code connection to prevent generating invalid code words;
- calculating a cumulative digital sum value (DSV) from the data words or tentative code words for each possible value of a DSV control bit;
- determining the DSV control bit which minimizes the absolute cumulative DSV when at least one subsequent DSV control bit is detected or after a predetermined delay;
- and
- generating final code words by modifying the DSV control bit in the tentative code word according to the determined DSV control bit.
2 more elements
A system for DSV control bit determination, comprising:
- a data word to partial DSV transferring circuit, generating partial digital sum values (DSV) of code words corresponding to data words by referring to the data words;
- a DSV accumulator, cumulating the partial DSVs as cumulative DSVs for possible values of a DSV control bit;
- and
- a DSV control bit generator, determining the value of a DSV control bit according to the cumulative DSVs, wherein the DSV control bit generator determines the value of a current DSV control bit which minimizes the absolute cumulative DSV when at least a subsequent DSV control bit is detected or after a predetermined delay.
1 more element
Dependencies are inferred from the claim text.