U.S. Philips Corporation

Koninklijke Philips Corporation N.v.

Other

Kornelis A Schouhamer Immink

Gijsbert Joseph Van Den Enden

Toshiyuki Nakagawa

Tatsuya Narahara

Josephus A H M Kahlman

Kosuke Nakamura

Josephus A Kahlman

Yoshihide Shinpuku

Ronaldus Maria Aarts

Lodewijk B Vries

Josephus Arnoldus Henricus Maria Kahlman

Yoshihide Shimpuku

Willem G Opheij

Ho Wai Wong-Lam

Kousuke Nakamura

Cornelis Marinus Johannes Van Uijen

Milton De Ribeiro Filho

A DSV control bit determining/inserting unitinserts DSV control bits for execution of DSV control into an input data string and outputs the data string including the DSV control bits to a modulation unitThe modulation unitconverts the data string with a basic data length of 2 bits into variable length code with a basic code length of 3 bits in accordance with a conversion table and outputs the code resulting from the conversion to a NRZI encoding unitThe conversion table used by the modulation unitincludes substitution codes for limiting the number of consecutive appearances of a minimum run to a predetermined value and substitution codes for keeping a run length limit. In addition, the conversion table enforces a conversion rule, according to which the remainder of division of the 'count of an element in a data string by 2 having a value of 0 or 1 shall always be equal to the remainder of division of the '1' count of an element in the code resulting from conversion of the data string by 2.

Modulation apparatus/method, demodulation apparatus/method and program presenting medium

A method of converting m-bit information words to a run-length constrained modulated signal includes converting the information words into n-bit code words. The available code words are distributed over at least one group (G) of a first type and at least one group (G) of a second type. The selection of a code word belonging to the group of the first or second type establishes a coding state of the first type (S) or one of a number r of coding states (S, S) of the second type, depending on the current information word. For each information word, a subset of code words is available, this subset having at least one disjunct code word for each of the r coding states. The selection from the subset of the code word to be delivered is based the coding state, on dynamically verifying the run-length constraint for the sequence of code words, and on an additional criterion, like the low frequency content of the modulated signal.

System of converting information words to a signal

How to record and play back data at a high line density. A DSV control bit determining/inserting unitinserts DSV control bits for execution of DSV control into an input data string and outputs the data string including the DSV control bits to a modulation unit. The modulation unitconverts the data string with a basic data length of 2 bits into variable length code with a basic code length of 3 bits in accordance with a conversion table and outputs the code resulting from the conversion to a NRZI encoding unit. The conversion table used by the modulation unitincludes substitution codes for limiting the number of consecutive appearances of a minimum run to a predetermined value and substitution codes for keeping a run length limit. In addition, the conversion table enforces a conversion rule, according to which the remainder of division of the '1' count of an element in a data string by 2 having a value of 0 or 1 shall always be equal to the remainder of division of the '1' count of an element in the code resulting from conversion of the data string by 2.

A DSV control bit determining/inserting unit inserts DSV control bits for execution of DSV control into an input data string and outputs the data string including the DSV control bits to a modulation unit. This modulation unit converts the data string with a basic data length of 2 bits into variable length code with a basic code length of 3 bits in accordance with a conversion table and outputs the code resulting from the conversion to a NRZI encoding unit. The conversion table used by the modulation unit includes substitution codes for limiting the number of consecutive appearances of a minimum run to a predetermined value and substitution codes for keeping a run length limit. In addition, the conversion table enforces a conversion rule, according to which the remaineder of division of the '1' count of an element in a data string by 2 having a value of 0 or 1 shall always be equal to the remainder of division of the '1' count of an element in the code resulting from conversion of the data string by 2.

The transmission system according to the invention comprises a transmitter () and a receiver (). The transmitter () can transmit datawords via a multicarrier signal () to the receiver (). In order to reduce the crest factor of this multicarrier signal () the transmitter () comprises a generator () and a selector (). The generator () generates for each dataword () a number of alternative sequences () by combining mutually different digital words with the dataword (). For this purpose, the generator () include an augmentor () and a scrambler (). The augmentor () generates for each dataword () a number of intermediate sequences () by combining the digital words with the dataword (). These intermediate sequences () are scrambled by the scrambler () in order to form the alternative sequences (). From these alternative sequences () the alternative sequence with the lowest peak power value () is selected for transmission to the receiver ().

Transmission system

The invention relates to a modulation code system, including an encoder and a decoder and two corresponding modulation code methods. More specifically, the encoder serves for transforming an original signal s into an encoded signal c satisfying predefined second constraints. Such encoder signals are, for example, transmitted via a channel or stored on a recording medium. After receipt or restoration, said encoded signal c is decoded by a decoder in order to regenerate the original signal s again. It is the object of the present invention to improve the known modulation code systems and methods in such a way that their embodiment requires less hardware. This object is solved in that the encoder comprises a series connection of a modulation code encoder and of a transformer encoder allowing an N-time integration of the output signal of said modulation code encoder . Moreover, this object is solved by embodying the decoder by a series connection of a transformer decoder for N-times differentiating the encoded signal c, and a modulation code decoder . N is an integer greater than 1.

Modulation code system and methods of encoding and decoding a signal by multiple integration

This invention relates to a digital modulation method and apparatus used for recording an audio or video signal, computer data, and etc on a recording medium such as an optical or magneto-optical disc. Data words of m bits are translated into code words of n bits in accordance with a conversion table. The code words satisfy a (d, k) constraint in which at least d &ldquo;0&rdquo;s and not more than k &ldquo;0&rdquo;s occur between consecutive &ldquo;1&rdquo;s. The n-bit code words alternate with p-bit merging words which are selected such that between the leading &ldquo;1&rdquo; in the code word following the merging word and the trailing &ldquo;1&rdquo; in the merging word are at least d &ldquo;0&rdquo;s, and further that between the trailing &ldquo;1&rdquo; in the code word preceding the merging word and the leading &ldquo;1&rdquo; in the merging word are at least d &ldquo;0&rdquo;s. The merging word that satisfies said conditions, yielding the lowest dc imbalance of the modulated signal obtained after modulo-2 integration of the catenation of the alternate code words and merging words is selected. Then, the modulated signal is generated by the catenation of alternate code words and merging words integrated modulo-2 in which a &ldquo;1&rdquo; becomes a transition and a &ldquo;0&rdquo; becomes an absence of a transition. A unique synchronizing word is inserted periodically.

Method of converting a series of m-bit information words into a modulated signal

How to record and play back data at a high line density. A DSV control bit determining/inserting unit inserts DSV control bits for execution of DSV control into an input data string and outputs the data string including the DSV control bits to a modulation unit . The modulation unit converts the data string with a basic data length of 2 bits into variable length code with a basic code length of 3 bits in accordance with a conversion table and outputs the code resulting from the conversion to a NRZI encoding unit . The conversion table used by the modulation unit includes substitution codes for limiting the number of consecutive appearances of a minimum run to a predetermined value and substitution codes for keeping a run length limit. In addition, the conversion table enforces a conversion rule, according to which the remainder of division of the &ldquo;1&rdquo; count of an element in a data string by 2 having a value of 0 or 1 shall always be equal to the remainder of division of the &ldquo;1&rdquo; count of an element in the code resulting from conversion of the data string by 2.

In a device for encoding a stream of databits of a binary source signal into a stream of databits of a binary channel signal the bitstream of the source signal is divided into n-bit source words. The device comprises converting means adapted to convert a block of p consecutive n-bit source words into a corresponding block of p consecutive m-bit channel words, such that the conversion for at least most of the n-bit source words is parity preserving and/or parity inverting, where m>n&gE;1. The converting means comprise memory means which contain for each n-bit source word a number of m-bit channel words, arranged in coding states, and a corresponding state number, indicating the state for a next m-bit channel word. After each block of source words q dc-control sourcebits are added, which are converted into r dc-control channelbits, independent of the conversion of a following source word.

DEVICE FOR ENCODING A STREAM OF DATABITS OF A BINARY SOURCE SIGNAL INTO A STREAM OF DATABITS OF A BINARY CHANNEL SIGNAL, MEMORY MEANS, DEVICE FOR RECORDING INFORMATION, RECORD CARRIER, DEVICE FOR CODING AND DEVICE FOR PLAYING BACK

A DSV control bit determining/inserting unit inserts DSV control bits into an input data string and outputs the string including the DSV control bits to a modulation unit which converts the string with basic data length of 2 bits into variable length code with basic code length of 3 bits in accordance with a conversion table and outputs the code resulting from the conversion to a NRZI encoding unit. The conversion table includes substitution codes for limiting the number of consecutive appearances of a minimum run and substitution codes for keeping a run length limit. The conversion table enforces a conversion rule: the remainder of division of the &ldquo;1&rdquo; count of an element in a data string by 2 having a value of 0 or 1 equals the remainder of division of the &ldquo;1&rdquo; count of an element in the code resulting from conversion of the data string by 2.

Device for encoding/decoding n-bit source words into corresponding m-bit channel words, and vice versa

An optical record carrier comprises a recording layer for recording information in a pattern of optically detectable marks in substantially parallel tracks. The tracks comprise alternating first and second servo tracks. The servo tracks have a track modulation different from the information pattern and indicative of position information. The position information in the first servo tracks, is encoded into m first words of channel bits and the position information in the second servo track, is encoded into n second words of channel bits where m and n are integers, and substantially all first and second words are different.

Optical record carrier and apparatus for scanning such a record carrier

The invention proposes an apparatus for encoding an information signal. The information signal can be a (d,k) sequence. The apparatus encodes the (d,k) sequence into a (d+n,k+n) sequence by changing the number of zeroes between each time two subsequent ones in the sequence by n. The information signal can also be a RLL sequence of the type (d,k). The apparatus encodes the signal into a RLL sequence of the type (d+n,k+n) by changing the runlengths by n bitcells each.

Encoding of an input information signal

An apparatus for decoding a channel signal into an information signal is disclosed. The channel signal comprises subsequent blocks of information, a block of information comprising a sync word and a plurality of channel words. The information signal includes subsequent information words. The apparatus includes an input terminal for receiving the channel signal, a conversion unit for converting the channel words into the information words, and an error concealment unit. The information signal obtained is supplied to an output terminal. The conversion unit includes a channel word detector for establishing whether channel words received are channel words not belonging to a group of valid channel words. If so, the channel word detector is adapted to supply a detection signal upon such detection. This enables the detection signals to be counted so as to establish a mis-synchronization of the decoding apparatus.

Apparatus for decoding a channel signal into an information signal and

An apparatus for transmitting a digital information signal includes an input terminal for receiving the digital information signal, a first channel encoding unit for carrying out a first channel encoding step on an information word in a series of subsequent information words included in the digital information signal so as to obtain a channel word, a compression unit for carrying out a compression step on a channel word so as to obtain a compressed channel word, an error correction encoding unit for carrying out an error correction encoding of the compressed channel word so as to obtain a parity word, a second channel encoding unit for carrying out a second channel encoding step on the parity word so as to obtain a channel encoded parity word, and a formatting unit for combining the channel word and the channel encoded parity word into a composite transmission signal suitable for transmission via a transmission medium. With such apparatus, very long information words can be converted into channel words, while serious error propagation is avoided during transmission.

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Eindhoven, Netherlands

Kornelis A Schouhamer Immink