Abstract: A method and system for encoding a segment of user data words into a segment of code words so that both modulation constraints and a predetermined parity-check constraint are satisfied. Each segment of the user data is partitioned into several data words, and encoded separately by first and second types of component code, which are referred to as the normal constrained code and the parity-related constrained code, respectively. The parity-check constraint over the combined code word is achieved by concatenating the sequence of normal constrained code words with a specific parity-related constrained code word chosen from a candidate code word set. Both the component codes are finite-state constrained codes, which are designed to have rates close to the Shannon capacity. Furthermore, they are based on the same finite state machine (FSM), which enables them to be connected seamlessly, without violating the modulation constraints.

Abstract: Method of converting information words, which includes receiving m-bit information words, where m is an integer, and converting the m-bit information words into n-bit code words based on a code conversion table including a plurality of coding states, where n is an integer greater than m. The plurality of coding states are categorized into a first kind or a second kind and a number of coding states of the first kind is greater than a number of coding states of the second kind. Each coding state includes at least two code words of a same value representing information words of a different value, and a minimum number of zeros between consecutive ones in the n-bit code words is 1.

Abstract: The present invention relates to method and apparatus of converting a series of data words into modulated signals. This method divides a data word, which a sync signal is to be added in front or rear of when it is written in a recording medium, into two or more word segments, generates for each word segment a number of intermediate sequences by combining mutually different digital words with that word segment, scrambles these intermediate sequences to form alternative sequences, translates each alternative sequence into a (d,k) constrained sequence, checks how many undesired sub-sequences are contained in each (d,k) constrained sequence, and selects one (d,k) constrained sequence for recording on an optical or magneto-optical recording medium among the (d,k) constrained sequences not having the undesired sub-sequence. Applying this method to a modulating device, DSV control can be conducted by much simpler hardware.

Abstract: Method of converting information words, which includes receiving m-bit information words, where m is an integer, and converting the m-bit information words into n-bit code words based on a code conversion table including a plurality of coding states, where n is an integer greater than m. The plurality of coding states are categorized into a first kind or a second kind and a number of coding states of the first kind is greater than a number of coding states of the second kind. Each coding state includes at least two code words of a same value representing information words of a different value, and a minimum number of zeros between consecutive ones in the n-bit code words is 1.

Abstract: A method and system for encoding a segment of user data words into a segment of code words so that both modulation constraints and a predetermined parity-check constraint are satisfied. Each segment of the user data is partitioned into several data words, and encoded separately by first and second types of component code, which are referred to as the normal constrained code and the parity-related constrained code, respectively. The parity-check constraint over the combined code word is achieved by concatenating the sequence of normal constrained code words with a specific parity-related constrained code word chosen from a candidate code word set. Both the component codes are finite-state constrained codes, which are designed to have rates close to the Shannon capacity. Furthermore, they are based on the same finite state machine (FSM), which enables them to be connected seamlessly, without violating the modulation constraints.

Abstract: In the coding device and method, m-bit information words are converted into n-bit code words such that the coding rate m/n is greater than ?. The n-bit code words are divided into a first type and a second type, and into coding states of a first kind and a second kind such that an m-bit information word is converted into an n-bit code word of the first or second kind if the previous m-bit information word was converted into an n-bit code word of the first type and is converted into an n-bit code word of the first kind if the previous m-bit information word was converted into an n-bit code word of the second type. In one embodiment, n-bit code words of the first type end in zero, n-bit code words of the second type end in one, n-bit code words of the first kind start with zero, and n-bit code words of the second kind start with zero or one.

Abstract: The present invention relates to a method of inserting sync patterns of different lengths in modulated data, and a recording medium having sync patterns produced by the method. The sector sync and the frame sync pattern to be inserted in modulated data in accordance with the present invention must satisfy the given (d,k) constraints, have distinctive 0's run the modulated channel data can not have, and be as short as it can. In addition, the frame sync pattern is shorter than the sector sync pattern because the frame sync pattern is more frequently inserted than the sector one. Owing to the present sync patterns, the storage capacity reduction of a recording medium due to necessary insertion of sync patterns can be minimized under a given modulation condition.

Abstract: In the coding device and method, m-bit information words are converted into n-bit code words such that the coding rate m/n is greater than 2/3. The n-bit code words are divided into a first type and a second type, and into coding states of a first kind and a second kind such that an m-bit information word is converted into an n-bit code word of the first or second kind if the previous m-bit information word was converted into an n-bit code word of the first type and is converted into an n-bit code word of the first kind if the previous m-bit information word was converted into an n-bit code word of the second type. In one embodiment, n-bit code words of the first type end in zero, n-bit code words of the second type end in one, n-bit code words of the first kind start with zero, and n-bit code words of the second kind start with zero or one.

Abstract: In the coding device and method, m-bit information words are converted into n-bit code words such that the coding rate m/n is greater than 2/3. The n-bit code words are divided into a first type and a second type, and into coding states of a first kind and a second kind such that an m-bit information word is converted into an n-bit code word of the first or second kind if the previous m-bit information word was converted into an n-bit code word of the first type and is converted into an n-bit code word of the first kind if the previous m-bit information word was converted into an n-bit code word of the second type. In one embodiment, n-bit code words of the first type end in zero, n-bit code words of the second type end in one, n-bit code words of the first kind start with zero, and n-bit code words of the second kind start with zero or one.

Abstract: In the coding device and method, m-bit information words are converted into n-bit code words such that the coding rate m/n is greater than ?. The n-bit code words are divided into a first type and a second type, and into coding states of a first kind and a second kind such that an m-bit information word is converted into an n-bit code word of the first or second kind if the previous m-bit information word was converted into an n-bit code word of the first type and is converted into an n-bit code word of the first kind if the previous m-bit information word was converted into an n-bit code word of the second type. In one embodiment, n-bit code words of the first type end in zero, n-bit code words of the second type end in one, n-bit code words of the first kind start with zero, and n-bit code words of the second kind start with zero or one.

Abstract: The present invention relates to method and apparatus of converting a series of data words into modulated signals. This method divides a data word, which a sync signal is to be added in front or rear of when it is written in a recording medium, into two or more word segments, generates for each word segment a number of intermediate sequences by combining mutually different digital words with that word segment, scrambles these intermediate sequences to form alternative sequences, translates each alternative sequence into a (d, k) constrained sequence, checks how many undesired sub-sequences are contained in each (d, k) constrained sequence, and selects one (d, k) constrained sequence for recording on an optical or magneto-optical recording medium among the (d, k) constrained sequences not having the undesired sub-sequence. Applying this method to a modulating device, DSV control can be conducted by much simpler hardware.

Abstract: A coding device and method in which m-bit information words are converted into n-bit code words such that the coding rate m/n is greater than ½. The coding device and method are also employed to record information on a recording medium and to transmit information. In the decoding method and apparatus, n-bit code words are decoded into m-bit information words. The decoding involves determining the state of a next n-bit code word, and based on the state determination, the current n-bit code word is converted into an m-bit information word. The decoding device and method are employed to reproduce information from a recording medium, and to receive information transmitted over a medium.

Abstract: A method and apparatus of converting a series of data words into modulated signals are provided. This method generates for each data word a number of intermediate sequences by combining mutually different digital words with that data word, scrambles these intermediate sequences to form alternative sequences, translates each alternative sequence into a (d,k) constrained sequence, checks whether each (d,k) constrained sequence contains undesired sub-sequence of more than kSET “0”s where kSET is smaller than k, and selects one (d,k) constrained sequence for recording on an optical or magneto-optical recording medium among the (d,k) constrained sequences not having the undesired sub-sequence, thereby recording edge information more frequently which will result in stable clock while conducting DSV control normally.

Abstract: A digital data modulating method wherein the last unit of a block consisting of predetermined units is received and a block is obtained which does not infringe A k-constraint in AN RLL code having (d, k) constraints on the basis of a modulation data table of a predetermined unit. A source code word to be modulated to a code word can be quickly and accurately determined while satisfying the (d, k) constraint of the RLL code between the blocks having a predetermined size.

Abstract: A digital data modulating method wherein the last unit of a block consisting of predetermined units is received and a block is obtained which does not infringe the k-constraint in the RLL code having the (d, k) constraints on the basis of a modulation data table of a predetermined unit. The source code word to be modulated to a code word can be quickly and accurately determined while satisfying the (d, k) constraint of the RLL code between the blocks having a predetermined size.

Abstract: The present invention relates to a method of inserting sync patterns of different lengths in modulated data, and a recording medium having sync patterns produced by said method. The sector sync and the frame sync pattern to be inserted in modulated data in accordance with the present invention must satisfy the given (d, k) constraints, have distinctive 0's run the modulated channel data can not have, and be as short as it can. In addition, the frame sync pattern is shorter than the sector sync pattern because the frame sync pattern is more frequently inserted than the sector one. Owing to the present sync patterns, the storage capacity reduction of a recording medium due to necessary insertion of sync patterns can be minimized under a given modulation condition.

Abstract: The present invention relates to method and apparatus of converting a series of data words into modulated signals. This ethod generates for each data word a number of intermediate sequences by combining mutually different digital words with that data word, scrambles these intermediate sequences to form alternative sequences, translates each alternative sequence into a (d,k) constrained sequence, checks whether each (d,k) constrained sequence contains undesired sub-sequence of more than kSET “0”s where kSET is smaller than k, and selects one (d,k) constrained sequence for recording on an optical or magneto-optical recording medium among the (d,k) constrained sequences not having the undesired sub-sequence, thereby recording edge information more frequently which will result in stable clock while conducting DSV control normally.

Abstract: The present invention relates to method and apparatus of converting a series of data words into modulated signals. This method divides a data word, which a sync signal is to be added in front or rear of when it is written in a recording medium, into two or more word segments, generates for each word segment a number of intermediate sequences by combining mutually different digital words with that word segment, scrambles these intermediate sequences to form alternative sequences, translates each alternative sequence into a (d, k) constrained sequence, checks how many undesired sub-sequences are contained in each (d, k) constrained sequence, and selects one (d, k) constrained sequence for recording on an optical or magneto-optical recording medium among the (d, k) constrained sequences not having the undesired sub-sequence. Applying this method to a modulating device, DSV control can be conducted by much simpler hardware.

Abstract: A coding device and method in which m-bit information words are converted into n-bit code words such that the coding rate m/n is greater than ½. The coding device and method are also employed to record information on a recording medium and to transmit information. In the decoding method and apparatus, n-bit code words are decoded into m-bit information words. The decoding involves determining the state of a next n-bit code word, and based on the state determination, the current n-bit code word is converted into an m-bit information word. The decoding device and method are employed to reproduce information from a recording medium, and to receive information transmitted over a medium.