Balanced disparity channel code for DC control
AssigneeKoninklike Philips Electronics N.V.
InventorJosephus Arnoldus Henricus Maria Kahlman
Life of this patent
Estimating the term…
Abstract
A coder is fed with precoded data such that the absolute value of the running digital sum (RDS) of the code words as produced by the coder is limited. This is achieved by ensuring that in a group of 2 code words, the RDS of the first code word is compensated by the RDS of the second code word. The RDS at the end of the second code word is then zero and the excursions of the RDS from the start of the first code word until the end of the second code word are limited because there are only a limited number of bits that can contribute to an increase of the absolute value of the RDS.
Claims25
A method for coding a stream of input words using a channel code, the method comprising the acts of:
- precoding the stream of input words into a stream of precoded input words;
- and
- coding the stream of precoded input words into a stream of groups of N code words
- such that a combined running digital sum of each predefined group of N adjacent code words equals zero.
An apparatus for storing data on a recording medium comprising an encoder which arranged for coding the stream of precoded input words into a stream of groups of N code words and comprising a precoder for coding the stream of input words into a stream of precoded input words such that a combined running digital sum of each predefined group of N adjacent code words equals zero.
A record carrier comprising a stream of input words stored as a stream of groups of N code words such that a combined running digital sum of each predefined group of N adjacent code words equals zero.
A method for decoding a stream of N code words into a stream of N output words, wherein the stream of M output words is postcoded to form postcoded words using the following table:
- In
- Out
- 1010
- 00
- 0001
- 01
- 0111
- 10
- 0101
- 11
- 00001000
- 1010;
- wherein “In” represents the stream of M output words and “Out” represents the postcoded words.
A method for decoding a stream of N code words into a stream of M output words, wherein the stream of M output words is postcoded to form postcoded words using the following table:
- In
- Out
- 1010
- 00
- 0001
- 10
- 0111
- 11
- 0101
- 01
- 00001000
- 1111;
- wherein “In” represents the stream of M output words and “Out” represents the postcoded words.
Dependencies are inferred from the claim text.