The invention relates to method of encoding address words (a) comprising address symbols (a.sub.0, a.sub.1, . . . a.sub.k-1) into codewords (c) of a code (C) for providing an enhanced error correction capability if at least one information symbol (m.sub.1) of information words (m) is known a priori to a decoder decoding received, possibly mutilated codewords (r). The invention relates further to a method of decoding possibly mutilated codewords (r). In order to design a code of which the correction power is enhanced if some information symbols are known to the decoder prior to decoding it is proposed according to the invention that the address words (a) are encoded into information words (m) such that that address words comprising addresses being close to each other share a plurality of information symbols and that said information words (m) are encoded into codewords (c) using a generator matrix (G) which is selected such that the minimum Hamming distance of at least one subcode (C') of said code (C) is larger than the minimum Hamming distance of said code (C) and that a subcode generator matrix (G') of said subcode (C') derives from said generator matrix (G) of said code (C) by omitting the at least one row from said generator matrix (G) corresponding to said at least one a priori known information symbol (m.sub.1).
A method and device for detecting and correcting errors in a data stream. For example, a method and device for detecting and correcting errors in a data stream including identifiers for a track address or identifiers for encoded words in a wireless transmission. The method and device employ a class of error correction codes to, for instance, encode track addresses on a surface of a data storage medium. The encoding modifies natural track addresses so that the difference between bit sequences in adjacent track addresses is constant while simultaneously enabling both error detection and error correction, thereby enabling more accurate head positioning in a data storage device, in one embodiment.
A method of detecting address information for an optical recording and/or reproducing apparatus, including: detecting and/or correcting by using the characteristic of a medium when additional data has a specific value with respect to an area of the medium among address area data on the medium, and/or the characteristic of an address that the address increases by specified unit, an error in detected address area data and outputting the result of error detection and/or correction; and providing optimal address information by using the result of the error detection and/or correction.
The present invention relates to a method and a device for the fast verification of sector addresses in a data stream obtained from a recording medium upon a request from a microcontroller. According to the invention, the method comprises the steps of: reading the data stream from the recording medium; decoding the data stream to obtain a decoded data stream comprising user data and sector addresses; comparing the sector addresses with a range of valid sector addresses; and transmitting only user data having sector addresses within the range of valid sector addresses; whereby dedicated comparing means are provided for performing the comparing step independently of the microcontroller.
