Abstract: The present invention concerns a method and apparatus of decoding a one-point algebraic geometric code defined on an algebraic curve represented by an equation in X and Z of degree 2?? in Z, where ? is a strictly positive integer and ? an integer greater than 1, obtained by taking the fiber product of ? component algebraic equations, each of said component equations governing the unknown X and an unknown Yi, where i=0, . . . , ??1, and being of degree 2? in Yi. This method comprises the decoding of 2(??1)? “clustered” codes, all defined on the same algebraic curve represented by one of said component equations.

Abstract: Method and apparatus for decoding a one-point algebraic geometric code of dimension k and length n, in order to identify the position of the errors in a received word, the syndromes matrix S, of dimension (n?k)×(n?k) is defined, of which the elements Sij of each line i are calculated, for j between 1 and w(i), where the boundary w is a decreasing function, using the syndrome s of the received word, as well as the matrix S* obtained by “extending” the matrix S, that is to say by calculating the value of certain elements S*ij where j is greater than w(i). This method makes it possible in certain favorable cases to find the erroneous positions of the received word when the number of errors is greater than (n?k+1?g)/2, even if it is not possible to calculate all the elements of S* conventionally required by a two-stage algorithm to perform that correction.

Abstract: A multimedia interface device for the transfer of information in a communications network comprises, at least two connection means to which, respectively, at least two sending devices can get connected by means respectively of two communications links compliant respectively with two protocols; means of connection to a single remote switching device by means of a single cable, the switching device comprising at least switching means between at least two ports; means to mix the information sent out by sending devices into only one stream of information in the form of segments being able to contain part of the information; and means to transfer the stream of information in the form of segments on at least one pair of cable to the switching device to which it is connected according to a third protocol.

Abstract: This wireless transmitter is composed of at least one modulator, which comprises a digital part and an analog part. The digital part comprises elements for generating the envelope of the signals to be transmitted and elements for generating the phase of the signals to be transmitted.

Abstract: The present invention concerns an encoding method in which encoding is performed of any information word a of length k in the form of a word ? belonging to a Reed-Solomon code C of dimension k? and length n? (with n??k?=n?k) such that the components of ?? situated in (n??n) arbitrary predetermined positions be systematically equal to respective predetermined constants (for example, all zero). The possibility then exists of deleting those components of fixed value to obtain a word ? of length n belonging to a code C, which thus constitutes a code that is shortened with respect to code C. The invention also relates to devices and apparatuses adapted to implement the encoding method. The invention may be used for encoding by means of an algebraic geometric code, when such encoding may be implemented by encoding by means of a plurality of shortened Reed-Solomon codes.

Abstract: The method of transmitting data in the form of symbols sent over an electromagnetic channel is characterized in that a measurement of significance is attributed to each group of data to be transmitted, in that the transmission reliability of the carriers is estimated dynamically, and in that the most significant data are sent over the most reliable carriers at each instant, the other data being sent over the carriers of decreasing reliability, in decreasing order of significance of the data.

Abstract: A modulation device comprises for each carrier frequency: means of discrimination between a signal coming from a first channel of a communications link and a signal coming from a second channel of said link, so as to obtain differentiated first and second signals; first assigning means, enabling the assigning of the first differentiated signal to one of the two modulation arms, and the second differentiated signal to the other of the two modulation arms.

Abstract: A multimedia interface device for the transfer of information in a communications network comprises: at least two connection means to which, respectively, at least two sending devices can get connected by means respectively of two communications links compliant respectively with two protocols; means of connection to a single remote switching device by means of a single cable, the switching device comprising at least switching means between at least two ports; means to mix the information sent out by sending devices into only one stream of information in the form of segments being able to contain part of the information; and means to transfer the stream of information in the form of segments on at least one pair of cable to the switching device to which it is connected according to a third protocol.

Abstract: The present invention concerns a method of decoding a one-point algebraic geometric code defined on an algebraic curve represented by an equation in X and Z of degree 2?? in Z, where ? is a strictly positive integer and ? an integer greater than 1, obtained by taking the fiber product of ? component algebraic equations, each of said component equations governing the unknown X and an unknown Yi, where i=0, . . . , ??1, and being of degree 2? in Yi. This method comprises the decoding of 2(??1)? “clustered” codes, all defined on the same algebraic curve represented by one of said component equations. The invention also relates to devices and apparatuses adapted to implement this method.

Abstract: The present invention concerns a method and an apparatus of generating a reference event in a receiving node receiving frames of information, when a frame of information is received, the method and the apparatus sample the frame of information in order to form sampled data, process sampled data in order to detect among said sampled data a specific data, monitor the number of processed sampled data until the detection of a specific data and generate a reference event according to the result of processing and monitoring.

Abstract: A method of encoding information symbols comprises a step in which a word v, orthogonal to a matrix H, the element H?? of which is equal to the value taken by some monomial h?=YjXi at the point P? of some locating set, is associated with every block of k information symbols belonging to a Galois field Fq. The invention shows how to choose the set of said monomials h? so as to define codes which can be decoded with an algorithm by aggregates of low complexity, and which provides a very good error correction capability, in particular for channels in which the errors tend to occur in bursts. The invention also relates to devices and apparatuses adapted to implement this method.

Abstract: A method of decoding a one-point algebraic geometric code defined on an algebraic curve of the kind C(a,b), represented by an equation of degree b in X and of degree a in Y, comprises, for any received word, a step of locating transmission errors affecting said received word. The correction of errors in said word, which belongs to an algebraic geometric code, is then reduced to the correction of errors in a certain number, at most equal to a, of words belonging to a Reed-Solomon code. Devices and apparatuses adapted to implement this method are also described.

Abstract: In a method of decoding a one-point algebraic geometric code of dimension k and length n, in order to identify the position of the errors in a received word, the syndromes matrix S, of dimension (n?k)×(n?k) is defined, of which the elements Sij of each line i are calculated, for j between 1 and w(i), where the boundary w is a decreasing function, using the syndrome s of the received word, as well as the matrix S* obtained by “extending” the matrix S, that is to say by calculating the value of certain elements S*ij where j is greater than w(i). This method makes it possible in certain favorable cases to find the erroneous positions of the received word when the number of errors is greater than (n?k+1?g)/2, even if it is not possible to calculate all the elements of S* conventionally required by a two-stage algorithm to perform that correction. Devices and apparatuses adapted to implement this method are also discussed.

Abstract: In order to evaluate the noise related to data issuing from a turbo-encoder: estimates of the noise related to its systematic output, to the data issuing from its first elementary encoder and to the data issuing from its second elementary encoder are determined (70); at least two of the estimates of the noise related to the systematic output, to the data issuing from the first encoder, and to the data issuing from the second encoder, are added (72); the results of these additions are divided (74) by the number of augends added, and then inverted (76), so as to obtain a noise factor; and the noise factor is multiplied with the data issuing from at least one of the first encoder, second encoder and systematic output.

Abstract: The present invention concerns a device (10) for the encoding of information symbols to transmit or to record, and for the correction of errors among the symbols received or read, according to codes defined over a Galois field Fq, where q is an integer greater than 2 and equal to a power of a prime number, and in which a set of elements of Fq are considered which are denoted yl(j), where j=1, . . . , R with 1?R?q?1 and l=0, . . . , p?1 with p>1.

Abstract: In order to evaluate the noise related to data issuing from a turbo-encoder, estimates of the noise related to its systematic output, to the data issuing from its first elementary encoder, and to the data issuing from its second elementary encoder are determined. At least two of the estimates of the noise related to the systematic output, to the data issuing from the first encoder, and to the data issuing from the second encoder, are added. The results of these additions are divided by the number of augends added, and then inverted, so as to obtain a noise factor, and the noise factor is multiplied with the data issuing from at least one of the first encoder, second encoder, and systematic output.

Abstract: Estimation of symbols related to each other by a parity relationship previously created by an encoder, is effected by a function having several components effecting a calculation of probabilities corresponding to a state of the encoder. The probabilities are of a first type, resulting from the observation of the effects of the previous states of the encoder on the current state, of a second type, resulting from the observation of the effects of the subsequent states of the encoder on the current state, and of a third type, representing the belonging of a symbol to a predetermined part of an encoding alphabet. A specific multiplexer is controlled by a state machine and cooperates with a calculator so that not only the probabilities of the first and second types but also the probabilities of the third type are obtained by one and the same circuit.

Abstract: The present invention concerns channel codes particularly well adapted to transmission in channels in,which errors tend to occur in bursts. Moreover, the codes according to one embodiment of the invention using an algebraic geometric curve are easy to decode and have a relatively high minimum distance. The invention also relates to the corresponding encoding and decoding methods, as well as the devices and apparatuses adapted to implement those methods. Application is in particular to mass storage, and to systems of communication by OFDM.

Abstract: This wireless transmitter is composed of at least one modulator, which comprises a digital part and an analog part. The digital part comprises elements for generating the envelope of the signals to be transmitted and elements for generating the phase of the signals to be transmitted.

Abstract: In a wireless communication network comprising at least one access point and one mobile terminal: