Method and apparatus of modulating/demodulating data for an optical recording medium
AssigneeLG Electronics Inc.
InventorSeong Keun Ahn
Life of this patent
Estimating the term…
Abstract
The present invention relates to method and apparatus for suppressing a DC component of coded sequence with no additional bit for suppressing a DC component, and for decoding the coded sequence. The present modulating method includes modulating the source data to a coded data based on at least one mapping table, the mapping table including a first table and a second table containing coded data corresponding to the source data, the first table being a 2/3 table containing 3-bit coded data for 2-bit source data, and the second table being a 4/6 table containing 6-bit coded data for 4-bit source data, wherein one of the first table and the second table is selected according to a bit sequence of the source data; and recording the coded data onto the optical recording medium.
Claims26
A method of modulating a source data to be written onto an optical recording medium under the conditions of a given code rate and limited run length, comprising the steps of:
- (a) modulating the source data based on a first mapping table and modulating the same source data based on a second mapping table, the first mapping table containing coded data corresponding to the source data, the second mapping table containing at least one coded data, capable of suppressing low frequency components, which at least one source data among all source data contained in the first mapping table is mapped to, wherein the first mapping table includes a 2/3 sub-table containing 3-bit coded data for 2-bit source data, a 4/6 sub-table containing 6-bit coded data for 4-bit source data, a 6/9 sub-table containing 9-bit coded data for 6-bit source data, and a 8/12 sub-table containing 12-bit coded data for 8-bit source data;
- and
- (b) selecting one of the modulated data based on at least one condition among the conditions of:
- the value of a previous source data, the time when low-frequency suppression has been conducted, the value of subsequent modulated data, and whether or not RLL constraints are violated.
A method of demodulating a channel data written onto an optical recording medium, comprising the steps of:
- (a) reading a channel data from the optical recording medium, the channel data having been modulated from a source data using a table selected among a plurality of mapping tables based on at least one condition among the conditions of:
- the value of a previous source data, the time when low-frequency suppression has been conducted, the value of subsequent modulated data, and whether or not RLL constraints are violated;
- and
- (b) demodulating the read channel data using a plurality of de-mapping tables in which a decoded data corresponding to the channel data is contained, wherein the de-mapping tables include a 3/2 sub-table containing 2-bit source data for 3-bit coded data, a 6/4 sub-table containing 4-bit source data for 6-bit coded data, a 9/6 sub-table containing 6-bit source data for 9-bit coded data, and a 12/8 sub-table containing 8-bit source data for 12-bit coded data.
An apparatus of modulating a source data to be written onto an optical recording medium under the conditions of a given code rate and limited run length, comprising:
- a modulator modulating the source data based on a first mapping table and modulating the same source data based on a second mapping table, the first mapping table containing coded data corresponding to the source data, the second mapping table containing at least one coded data, capable of suppressing low frequency components, which at least one source data among all source data contained in the first mapping table is mapped to, wherein the first mapping table includes a 2/3 sub-table containing 3-bit coded data for 2-bit source data, a 4/6 sub-table containing 6-bit coded data for 4-bit source data, a 6/9 sub-table containing 9-bit coded data for 6-bit source data, and a 8/12 sub-table containing 12-bit coded data for 8-bit source data;
- and
- a controller selecting one of the modulated data based on at least one condition among the conditions of:
- the value of the source data, the time when low-frequency suppression has been conducted, the value of subsequent modulated data, and whether or not RLL constraints are violated.
An apparatus of demodulating a channel data written onto an optical recording medium, comprising:
- a detector reading a channel data from the optical recording medium, the channel data having been modulated from a source data using a table selected among a plurality of mapping tables;
- and
- a demodulator demodulating the read channel data using a plurality of de-mapping tables in which a decoded data corresponding to the channel data is contained, wherein the de-mapping tables include a 3/2 sub-table containing 2-bit source data for 3-bit coded data, a 6/4 sub-table containing 4-bit source data for 6-bit coded data, a 9/6 sub-table containing 6-bit source data for 9-bit coded data, and a 12/8 sub-table containing 8-bit source data for 12-bit coded data.
A method of modulating a source data to be written onto an optical recording medium under the conditions of a given code rate and limited run length, comprising the steps of:
- (a) modulating the source data to a coded data based on at least one mapping table, the mapping table including a 2/3 table containing 3-bit coded data for 2-bit source data, a 4/6 table containing 6-bit coded data for 4-bit source data, a 6/9 table containing 9-bit coded data for 6-bit source data, and an 8/12 table containing 12-bit coded data for 8-bit source data, wherein one of the tables is selected according to a bit sequence of the source data;
- and
- (b) recording the coded data onto the optical recording medium.
A method of demodulating a coded data written onto an optical recording medium, comprising the steps of:
- (a) reading a coded data from the optical recording medium, the coded data having been modulated from a source data using a table selected among a plurality of mapping tables based on at least a bit sequence of the source data;
- and
- (b) demodulating the read coded data using a plurality of de-mapping tables, wherein the de-mapping tables includes a 3/2 table containing 2-bit source data for 3-bit coded data, a 6/4 table containing 4-bit source data for 6-bit coded data, a 9/6 table containing 6-bit source data for 9-bit coded data, and a 12/8 table containing 8-bit source data for 12-bit coded data.
Dependencies are inferred from the claim text.