Hitachi Global Storage Technologies Netherlands B.v.

Masaharu Kondou

Terumi Takashi

Hideki Sawaguchi

Morishi Izumita

Yasuyuki Itou

Embodiment of the invention is to make the number of interleave sequences and the number of redundant bits as small as possible without increasing the number of bits per symbol so much. By encoding data into an error-correcting code by using an algebraic geometric code consisting of an algebraic curve surface having a genus g over a projective plane P(GF()), where m is a positive integer, the code up to a length of 22g is constructed. In particular, by using a 'Fermat code,' a version of the algebraic geometric code, consisting of a Fermat curve 'C: X+Y+Z=0' over the P(GF(2)), where (m, L)=(5, 11), 4-Kbyte data constituting one sector can be encoded into the code made up of 10-bit symbols.

Recording/regenerating device, method of encoding error correction, method of recording data

Embodiments of the invention a signal processing method capable of realizing low decoding error ratio by using a simple configuration free from unnecessary redundant bits. In one embodiment, user data (512 bytes+additional data) input to an input terminal is RLL-encoded by a RLL encoder. The data from the RLL encoderis entered into a symbol error correction encoder where 9-bit symbol encoding is done. Its RS code portion is RLL-encoded by a RLL encoder. Signal read from a magnetic disk is entered into a RLL decoderwhere the RS code portion is RLL-decoded. The signal from the RLL decoderis then entered into a symbol error correction decoder where random read/write errors, burst errors attributable to defects and other errors are corrected to produce a (user data+RLL) signal. This data is output to an output terminal after being decoded by a RLL decoder

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Kanagawa, Japan

Masaharu Kondou