U.S. Philips Corporation

Sony Corporation

U.S. Phillips Corporation

Constant P Baggen

Ludovicus M Tolhuizen

Erik W Gaal

Yoichiro Sako

Tadao Suzuki

Cornelis M Van Uijen

Tsuneo Furuya

Arie G Koppelaar

Shunsuke Furukawa

Johannes J Verboom

Gerardus C Lokhoff

Josephus A Kahlman

Lodewijk B Vries

Leonardus M Driessen

Hendrik D Hollmann

Rudy W Pollen

Johannes I Tichelaar

Shunske Furukawa

Lodewijk B Vries, Deceased

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

Data is transmitted via a signal containing a number of simultaneously active modulated frequency channels. The data is encoded in an error protecting code. Successive data items are mapped pseudo-randomly to different frequency channels. This protects against fading which affects frequency channels that are located at periodic distances from each other. The pseudo random mapping is realized by writing the data-items into memory in one order and reading them from memory in another order. Successive signals are each modulated in this way. The memory locations vacated upon reading data items for the modulation of one signal are filled by data-items for modulating the next successive signal. This is kept up by permuting the order of the memory locations in which the data-items are written for each successive signal.

Method of error protected transmission, method of error protected

Recording apparatus for recording in a track on an optical information carrier a first channel signal representing a main information signal, a second channel signal representing a cue information signal and a third channel signal representing a sub information signal. The main information signal includes at least one programme item and the cue information signal includes for the at least one programme item an indication of its location on the track. The recording apparatus includes a unit for receiving the main information signal, the cue information signal and the sub information signal; a unit for encoding the main information signal providing the first channel signal; a unit for encoding the cue information signal, providing the second channel signal; a unit for encoding the sub information signal, providing the third channel signal carrying sub information packs in substantially non-interleaved form, by generating sub information packs, including data from the sub information signal plus data for error detection and correction thereof, in substantially non-interleaved form; and a unit for writing the first channel signal in a main information area of the track on the information carrier and for writing the second channel signal and the third channel signal in a lead-in area of the track preceding the main information area.

Transferring information via the lead-in area of an information carrier

A circuit arrangement calculates pseudo-random permutations of a set of numbers. Including compositions of some basic pseudo-random permutations and the inverse permutations of permutations that are calculated. The basic pseudo-random permutations, their compositions and inverses are all calculated by the same generator whose operation is commanded to calculate the appropriate permutation by specifying a set of integer coefficients f.sub.i. The generator calculates the permutations .sigma.(n) of the numbers n=0 . . . m-1 corresponding to ##EQU1## where .alpha. is an integer number which is divisible by all prime factors of m and by four if m is divisible by four, with a potency s(.alpha.) of two or higher. When the same a is used for all permutations it is assured that all compositions and inverses of the generated permutations can be calculated in the same way, by the same generator. By storing a batch of items in a storage medium in a first order and retrieving the items from the storage medium in a second order, the first and second order corresponding to different permutations which are both of this type, it is made possible to permute the batch pseudo randomly and start storing the batch of items in the storage medium before a previous batch has been fully retrieved from it.

Circuit arrangement comprising a permutation unit and method of

Extended error protected communication system. An extended consumer communication system uses a signal that is error protected by a block code. The generator polynomial is

Method and apparatus for decoding an error protected block of extended

Receiver for receiving a transmission signal comprising N frequency multiplexed data modulated carriers, having a good compromise between insensitivity to multipath reception and receiver complexity, and which may enable a reduction in transmission bandwidth and transmitter power. In such a receiver, modulation signals of the carriers are supplied by a frequency multiplex demodulator to a symbol detection device via an equalizer device. The equalizer device compensates distortion in the modulation signals supplied thereto, such that the symbol detection device may detect the transmitted data with reduced error probability. When the transmission signal reaches the receiver with different delay times, this distortion is mainly a kind of cross-talk between the modulation of adjacent carriers. Therefore substantial compensation is achieved by combining the modulation signal of a carder with signals representative of the data of the adjacent carriers. In the receiver, these signals may be obtained from the multiplex signal path between the frequency multiplex demodulator output and the output of the symbol detection device.

Receiver

Methods and devices for encoding data symbols in accordance with a BCH code to obtain a code word in which parity symbols are located in the middle of the code word. The data symbols are supplied to a parity determining device in a predetermined order to produce the parity symbols, which parity determining device either employs a shift register or a shift register bank. When the parity determining device employs a shift register, depending upon the predetermined order in which the data symbols are supplied to the shift register, the data symbols are either (a) forward shifted through the shift register, after each data symbol has been initially modified on the basis of previously supplied data symbols, and further modified as each is being shifted through the shift register on the basis of subsequently received data symbols so as to produce the parity symbols or (b) forward shifted through the shift register, after each data symbol has been modified on the basis of previously supplied data symbols, so as to produce provisional parity symbols which are, in turn, backward shifted through the shift register to produce the parity symbols. Once the parity symbols have been produced, they are positioned among the data symbols so as to produce the code word.

Methods and devices for encoding data symbols in accordance with a BCH

The invention relates to a method of transmitting data by modulating a frequency multiplex of carriers at a relatively low symbol rate, such as in OFDM (orthogonal frequency division multiplex). According to the inventive method, intersymbol interference is deliberately introduced at the transmitter side to reduce cross-talk between data of different carriers at the receiver side, such as to simplify an equalizing device in a receiver. The intersymbol interference at the transmitter side is introduced after the frequency multiplex modulation has taken place, by repeating groups of output symbols produced by an IFFT transformer and subsequently shaping these repeated groups by means of symbol-by-symbol scaling with coefficients constituting a window function. Subsequent shaped and repeated groups of these output symbols mutually overlap.

Method of transmitting a data stream, transmitter and receiver

An extended television signal comprises control data for controlling an extended television decoder. The control data comprise first information bits (NB) for conveying information which need not be very reliably decodable immediately upon switching between broadcast channels or when their contents have changed. Each first information bit (NB) is channel-encoded by means of a first DC-free channel code into first channel bits each having a first duration (2 Tc). The control data further comprise second information bits (LB) for conveying information which must be very reliably decodable immediately upon switching between broadcast channels or when their contents have changed. Each second information bit (LB) is channel-encoded by means of a second DC-free channel code into second channel bits which each have a second duration (10 Tc) exceeding the first duration (2 Tc).

An extended television signal encoding and decoding system comprising

A method and apparatus for decoding code words which are error protected by a non-binary BCH-code against at least one symbol error. Upon reception of an input code word a syndrome information thereof is generated under control of code defining information. From the syndrome information, a key equation is set up and solved for generating an error locator polynomial sig (z) and an error evaluator polynomial w(z). On the basis of the polynomial sig (z) and its formal derivative polynomial sig' (z), Euclid's algorithm is employed to calculate two accessory polynomials b(z), c(z), such that b(z)sig(z)+c(z)sig'(z)=1. From these, a Lagrangian polynomial L(z) is calculated which for any inversed error location value has the associated error symbol value. The error data is then calculated by evaluating the error locator polynomial and the Lagrangian polynomial.

Method and apparatus for decoding code words protected wordwise by a

A method is revealed for recording an information signal (Vi) on a record carrier (1). The information signal (Vi) is converted into code words (200), which comprise a variable number of bits of a first logic value ('1') and a variable number of bits of a second logic value ('0'). The number of successive bits of the first logic value ('1') is at least equal to P. The number of successive bits of the second logic value, situated between the bits of the first logic value, is at least equal to Q, Q being greater than P. A pattern of recording marks (8;54) corresponding to the code signal (Vc) is recorded on the record carrier (1) in such a way that bits of the first logic value ('1') are represented by recording marks (8;54). Moreover, an information recording device (FIG. 17), an information read device, and a decoding device (FIG. 18) are revealed.

Method of and device for recording information, record carrier, device

A description is given of a semiconductor memory with an on-chip error correction facility. The code used is defined over the location domain of the columns. The columns are arranged in patterns of non-redundant and redundant memory cells which recur with a fixed period. As a result of the convolution code chosen, decoding is possible by way of a small number of series connected gates, so that the time delay is limited. The correction capability of the code is only partly used because complete use could cause additional delay.

Semiconductor memory comprising an on-chip error correction device, and

Information is transmitted by a digital audio transmission line, which may include recording and playback from a digital audio disc, that includes information other than conventional two-channel audio signals and in which error correction of the data transmitted in either direction between a user and a medium is provided. Information integrity is maintained by a first and second cross-interleave Reed-Solomon code (CIRC), in which a third Reed-Solomon code is overlaid on the CIRC code, whereby a sector is built from user words and protected by a quasi-product code, and then an encoded sector is divided into groups, which are group-wise presented to the CIRC encoder.

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Eindhoven, Netherlands

Constant P Baggen