U.S. Philips Corporation

U.S. Phillips Corporation

Ludovicus M Tolhuizen

Constant P Baggen

Adrianus J Denissen

Wilhelmus H Bruls

A method and apparatus for trackwise burst error correction in multitrack storage has an error protective code format that is based on first and second linear block codes each with a plurality of symbols. Of each word pair that consists of one word from either code, and whose words have a pivot symbol in common, the latter words have mutually different cross-track orientations. Each individual symbol forms the pivot symbol of one such word pair. The method first decodes an error-decodable word pair having such pivot symbol in common. The next word pair is minimally shifted with respect to the latter pivot symbol and is then decoded, such shifting being non-uniform as based on the outcome of a most recent decoding. The method then alternates the shifting and decoding steps.

Method and apparatus for trackwise burst error correction in a

For error-protected storing data, the data is encoded by an error protecting code to encoded data and stored in a medium. Next, the data is read out again and compared with the encoded data. If a particular discrepancy between stored data and encoded data is found, a discrepancy identifier is formed and stored with the stored data for raising the error protection by the error protecting code.

Method and device for error protection of programmable memories

Error correctable data transmission method and device based on

A transmitter apparatus for transmitting a digital data signal via a transmission medium (10) includes an error protection encoder (3) for carrying out an error protection encoding on the digital data signal so as to obtain an error protection encoded digital data signal, and a channel encoder (6) for converting the error protection encoded digital data signal processed into a channel encoded digital data signal. The channel encoded digital data signal is supplied to the transmission medium. The error protection encoder (3) is adapted to carry out an error protection encoding step on packets of p m-bit digital words in the digital data signal, and for supplying error protection encoded packets (Q) of n m-bit digital words to an output, where n, m and p are integers larger than 1, and n&gt;p. The channel encoder (6) is adapted to convert the error protection encoded packets of n digital words into converted packets (CP, CP') of digital words to form the channel encoded digital data signal and has a generator (60) for supplying at least fixed auxiliary packet (Q.sub.f.1, Q.sub.f.2) also having the length of n digital words. The channel encoder further includes a calculator (58, 66) for calculating, in a Galois field GF(2.sup.m), a converted digital word CW.sub.i in accordance with the formula DW.sub.i +.alpha..sub.1 .multidot.FW.sub.1.i +.alpha..sub.2 .multidot.FW.sub.2.i + . . . , where DW.sub.i is the binary value corresponding to the i-th digital word in the packet (Q), FW.sub.1.i and FW.sub.2.i being the fixed binary values corresponding to the i-th digital word in the first and second fixed auxiliary packet (Q.sub.f.1, Q.sub.f.2), respectively, and CW.sub.i is the binary value of the i-th converted digital word in the converted packet (CP, CP') of digital words, where i is an integer value running from 1 to n.

Apparatus and methods for use in transmitting and relieving a digital

Apparatus and methods for transmitting and receiving a digital data signal. At the transmitter side, packets of p m-bit digital words in a digital signal are error protection encoded to produce error protection encoded packets of n m-bit digital words making up an error protection signal, where n&gt;p. The error protection encoded packets are converted into converted packets of digital words to form a channel encoded signal, which signal is supplied to a transmission medium. The conversion involves use of a generator for supplying a fixed auxiliary packet of n digital words; a calculation unit for calculating in a Galois field GF(2.sup.m) a converted digital word in accordance with the formula DW.sub.i +.alpha..FW.sub.i, where DW.sub.i and FW.sub.i are the binary values corresponding to the i-th digital words in the packet to be converted and the auxiliary packet, respectively, .alpha. is a binary value, and the converted digital word is the i-th converted digital word in the converted packet, where i runs from 1 to n; and a digital sum value determining unit for determining the digital sum value of at least a converted packet in the channel encoded signal. The calculation unit determines a value .alpha..sub.def with the converted digital words obtained by the Galois field GF(2.sup.m) calculation of DW.sub.i +.alpha..sub.def. FW.sub.i so as to obtain the converted packet, the value .alpha..sub.def for .alpha. being such that a running digital sum value of the converted packets shows a desired pattern as a function of time. The receiver side operates in an opposite manner.

Apparatus and methods for use in transmitting and receiving a digital

An encoder arrangement (28) for adapting a data signal for recording of the data signal on a D-type magnetic recording apparatus includes an error correction encoding unit (3), a converter unit (6) and a shuffling unit (9). A decoder arrangement (30) for reconverting the signal obtained after reproduction from a D-type reproduction apparatus includes comprises a deshuffling unit (14), an error correction decoding unit (17) and a reconverter unit (20).

Conversion arrangement for a magnetic recording/reproducing apparatus of

Methods and apparatus for encoding and/or decoding digital data elements of a uniform size with different degrees of error protection in accordance with a quasi-product code. The data elements are encoded by (a) distributing the data elements over an array of at least two dimensions, made up of lines in each of the at least two dimensions, so that at least two lines in a first one of the dimensions have a different number of data elements therein; (b) supplementing the data elements in the first one of the dimensions with first redundant elements of the uniform size in accordance with one or more first systematic codes so that all lines in that dimension containing one or more data elements therein have the same number of elements therein and each of those lines contains at least one separate first redundant element therein providing error protection to that line; and (c) supplementing the data elements and the first redundant elements in a second one of the dimensions with second redundant elements of the uniform size in accordance with one or more second systematic codes so that all lines in that dimension containing one or more data elements and/or first redundant elements therein have the same number of elements therein and each of those lines contains at least one separate second redundant element therein providing error protection to that line. The data elements are decoded by decoding the lines in each dimension, one dimension at a time.

Growing community of inventors

Eindhoven, Netherlands

Ludovicus M Tolhuizen