Two stage coding method
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsKiyoshi Matsutani, Ken Ohnishi
Life of this patent
Estimating the term…
Abstract
Errors which arise in recording and reproducing data in a recording material are corrected with the use of an error correction code such as an RS (Reed-Solomon) code, and a two stage C.sub.2 and C.sub.1 coding method is conducted at an interval of repetition of a combination of [k.sub.2 /n.sub.2 ] and [k.sub.2 /n.sub.2 ]+1 on digital data having a two dimensional arrangement of k.sub.1 in the first direction and k.sub.2 in the second direction, whereby burst error correction ability is enhanced by the enhancement of error correction capacity.
Claims27
A two stage coding system for encoding digital information arranged in a matrix of k.sub.1 .times.q digits in a first direction, and k.sub.2 digits in a second direction orthogonal to the first direction, wherein
- K.sub.1, q, and k.sub.2 are integers,
- K.sub.1 <k.sub.2 ;
- q=the number of digits per data word, and
- K.sub.1, K.sub.2 =the number of data words in said first and second directions respectively, comprising:
- C.sub.2 encoder means for encoding said digital information with a C.sub.2 code on a Galois Field GF (2.sup.q), including means for [numbering] selecting data words in said matrix diagonally from an arbitrary data word a.sub.1 and establishing a.sub.2 to a.sub.n2, wherein n.sub.2 is the length of [code] the C.sub.2 encoded data, such that ##EQU8## wherein h.sub.1 to h.sub.n2-1 satisfy the following
- h.sub.2i-1 =[K.sub.2 /n.sub.2 ]
- h.sub.2i =[k.sub.2 /n.sub.2 ]+1 1.ltoreq.i.ltoreq.(n.sub.2 -1)/.Badd.2 said C.sub.2 encode means including means for C.sub.2 encoding said [numbered] selected data words, and means for adding the obtained C.sub.2 code to an end of said matrix in said first direction;
- and
- C.sub.1 encoder means for encoding said C.sub.2 encoded matrix with a C.sub.1 code having a predetermined length [of n.sub.1 ] on a GF (2.sup.q) for each row of data words in said first direction, and adding the obtained C.sub.1 code to an end of said matrix in said first direction.
A two stage coding system for encoding digital information arranged in an information matrix of k.sub.1 .times.q digits in a first direction, and k.sub.2 digits in a second direction orthogonal to the first direction, wherein
- k.sub.1, q, and k.sub.2 are integers,
- k.sub.1 <k.sub.2 ;
- q=the number of digits per data word, and
- k.sub.1, k.sub.2 =the number of data words in said first and second directions respectively, comprising:
- C.sub.2 encoder means for encoding said digital information with a C.sub.2 code on a Galois field GF(2.sup.2), said C.sub.2 encoder means selecting data words in said information matrix diagonally from an arbitrary data word a.sub.1 and including a.sub.2 to a.sub.n2, wherein n.sub.2 is the length of the C.sub.2 encoded data, such that
- a.sub.2 =a.sub.1 +n.sub.2 .times.h.sub.1 +1
- a.sub.3 =a.sub.2 +n.sub.2 .times.h.sub.2 +1
- :
- a.sub.k1 =a.sub.k1-1 +n.sub.2 .times.h.sub.k1-1 +1
- :
- a.sub.n2 =a.sub.n2-1 +n.sub.2 .times.h.sub.n2-1 +1,
- h.sub.1 to h.sub.2n-1 each being selected from one of h.sub.A and h.sub.B, wherein,
- h.sub.A =[k.sub.2 /n.sub.2 ],
- h.sub.B =[k.sub.2 /n.sub.2 ]+1, and
- h.sub.A .times.l.sub.1 +h.sub.B .times.l.sub.2 .ltoreq.k.sub.2, where
- l.sub.1 +l.sub.2 =n.sub.2
- said C.sub.2 encoder means forming said C.sub.2 code from said selected data words and adding the obtained C.sub.2 code to an end of said information matrix in said first direction thereby forming a C.sub.2 encoded matrix;
- and
- C.sub.1 encoder means for encoding each line in said first direction of said C.sub.2 encoded matrix with a C.sub.1 code having a predetermined length on a GF(2.sup.q), and adding the obtained C.sub.1 code to an end of each said line of said matrix in said first direction to form a C.sub.2
- C.sub.1 encoded matrix.
A two stage coding system for encoding digital information arranged in an information matrix of k.sub.1 .times.q digits in a first direction, and k.sub.2 digits in a second direction orthogonal to the first direction, wherein
- k.sub.1, q, and k.sub.2 are integers,
- k.sub.1 <k.sub.q ;
- q=the number of digits per data word, and
- k.sub.1, k.sub.2 =the number of data words in said first and second directions respectively,
- said system further single stage coding additional information of k.sub.3 .times.q digits in the first direction, where k.sub.3 is an integer and k.sub.2 digits in the second direction, comprising:
- C.sub.2 encoder means for encoding said digital information with a C.sub.2 code on a Galois field GF(2.sup.q), said C.sub.2 encoder means selecting data words in said information matrix diagonally from an arbitrary data word a.sub.1 and including a.sub.2 to a.sub.n2, wherein n.sub.2 is the length of the C.sub.2 encoded data, such that
- a.sub.2 =a.sub.1 +n.sub.2 .times.h.sub.1 +1
- a.sub.3 =a.sub.2 +n.sub.2 .times.h.sub.2 +1
- :
- a.sub.k1 =a.sub.k1-1 +n.sub.2 .times.h.sub.k1-1 +1
- :
- a.sub.n2 =a.sub.n2-1 +n.sub.2 .times.h.sub.n2-1 +1
- h.sub.1 to h.sub.n2-1 each being selected from one of h.sub.A and h.sub.B, wherein,
- h.sub.A =[k.sub.2 /n.sub.2 ],
- h.sub.B =[k.sub.2 /n.sub.2 ]+1, and
- h.sub.A .times.l.sub.1 +h.sub.B .times.l.sub.2 .ltoreq.k.sub.2, where
- l.sub.1 +l.sub.2 =n.sub.2
- said C.sub.2 encoder means forming said C.sub.2 code from said selected data words and adding the obtained C.sub.2 code to an end of said information matrix in said first direction to form a C.sub.2 encoded matrix;
- and
- said additional data of k.sub.3 words and said C.sub.2 encoded matrix collectively forming an added data matrix having k.sub.2 lines;
- C.sub.1 encoder means for encoding each of said k.sub.2 lines extending in said first direction of said added data matrix with a C.sub.1 code having a predetermined length on a GF(2.sup.q), and adding the obtained C.sub.1 code to an end of each said line of said added data matrix in said first
- direction to form a C.sub.2 C.sub.1 encoded matrix.
Dependencies are inferred from the claim text.