Abstract: For encoding a source sequence of symbols (u) as an encoded sequence, the source sequence (u) is divided into p1 first sub-sequences (Ui), p1 being a positive integer, and each of the first sub-sequences (Ui) is encoded in a first circular convolutional encoding method. The source sequence (u) is interleaved into an interleaved sequence (u*), and the interleaved sequence (u*) is divided into p2 second sub-sequences (U?i), p2 being a positive integer. Each of the second sub-sequences (U?i) is encoded in a second circular convolutional encoding method. At least one of the integers p1 and p2 is strictly greater than 1 and at least one of the first sub-sequences (Ui) is not interleaved into any of the second sub-sequences (U?j). (It is noted that the above underlining of the following symbols is original, and is meant to be permanent: u, Ui, u*, U?i, U?j).

Abstract: A compression method adapts a digital format in which information representing a physical quantity is accompanied by predictable data having a value independent of that of the information representing a physical quantity. The method includes an operation of reducing the number of the predictable data, the data and information representing a physical quantity resulting from this reduction operation being able to allow the reconstitution of predictable data accompanying the information representing a physical quantity, in accordance with the digital format. Preferentially, the reduction operation includes a step of removing the predictable data, and a step of inserting substitution data, having a number less than the number of data removed during the removal step.

Abstract: In order to encode an original sequence of binary data (u), a first padding operation (508) is performed, supplementing the original sequence (u) so that the supplemented sequence (u) is divisible by a first divisor polynomial; a first recursive convolutional encoding operation (508) is performed, using the first divisor polynomial, encoding the supplemented original sequence (u); an interleaving operation (506) is performed, permuting the binary data in the original sequence (u) by means of a specific permutation, so as to obtain an interleaved sequence (u*); a second padding operation (510) is performed, supplementing the interleaved sequence (u*) so that the supplemented interleaved sequence (u*) is divisible by a second divisor polynomial (g2); and a second recursive convolutional encoding operation (510) is performed, using the second divisor polynomial, encoding the supplemented interleaved sequence (u*).

Abstract: The coding method to which the present invention relates takes into account at least one selection criterion related to a transmission of binary symbols representing a physical quantity, for selecting at least one transmission parameter. Each said selected transmission parameter is in the set of parameters comprising: a number K, greater than or equal to 1, of sequences ai (i=1, . . . , K) of binary symbols, to be coded, an integer M1, equal to or greater than 2, a divisor polynomial gi(x), an integer M, an interleaver, and a multiplier polynomial fij(x). It uses an interleaver which maintains the divisibility by a polynomial gi(x).

Abstract: The invention concerns a method for access to a transmission channel shared between several stations, characterised in that it includes iteratively: an operation (302) of estimating requirements of each of the stations for access to the transmission channel, an operation of determining groups (303 and 307) of stations taking into account the estimated access requirements of the stations, at least one of the groups of stations being said to be “collective”, an operation of allocating (308), to each of the groups, access rights each corresponding to an interval of time during which the stations which do not form part of the group are not authorised to access the transmission channel, and during which, if the group is collective, each station which it includes gains access to the transmission channel according to a contention method.

Abstract: The coding method to which the present invention relates takes into account: a polynomial without square g(x), N0, the smallest integer such that g(x) is a divisor of the polynomial xN0+1; n, an odd multiple of N0; a sequence u of n symbols ui to be coded; and e, a power of 2 different from 1, which is residue of e modulo N0 is equal to 1. It includes: an operation of forming a concatenated sequence uu* (304) consisting successively of the sequence u and a sequence of symbols u* such that u*(x)=u(xe) modulo xn+1, an operation of coding the concatenated sequence uu* (305), including at least one division of the concatenated sequence uu* by the polynomial g(x).

Abstract: The invention proposes interleaving binary symbols representing a physical quantity, used in a coding system with at least two recursive convolutional coders each having a divisor polynomial which all share the same given period, or used in a decoding system corresponding to the coding system, comprising writing binary symbols in a table having a first number of columns, equal to the period of the coders, and a second number of rows, performing first permutations of the symbols on each of the columns, and performing second permutations of the columns with each other, the second permutation preserving the property of return to zero of the coders.

Abstract: The decoding method to which the present invention relates takes into account: at least one predetermined polynomial, and a received sequence r capable of being the result of the coding of a sequence of information symbols of polynomial representation u(x) representing a physical quantity, the coding including a turbocoding, and guaranteeing the divisibility of a sequence to be turbocoded, a(x) representing the sequence u(x), by each predetermined polynomial, This method includes: an operation of turbodecoding (601) the received sequence r into an estimated sequence â, at least one operation of calculating the remainder (602, 606) of the division of the polynomial representation â(x) of the estimated sequence â, by a said predetermined polynomial.

Abstract: A method of transmitting binary data by a sender to a receiver over a transmission channel includes a formatting function integrated with a function of external coding of the binary data. The method applies in particular to the case where the sender uses a turbocoder with an interleaver of the “x to xe” type, and where the receiver uses a turbodecoder with an interleaver of the “x to xe” type.

Abstract: A method of transmitting information on a transmission channel associated with a first numerical alphabet that takes into account a matrix n×n with an orthogonal dominant H on a second numerical alphabet including at least three different non-null values, and a set of at least one sub-matrix of the matrix H, each sub-matrix of the set containing a number p greater than or equal to 2 rows of the matrix H. A sub-matrix from the set of sub-matrixes is selected along with a p-tuple of real numbers referred to as a “row of coefficients”, such that the matrix product of the row of coefficients and the selected sub-matrix supplies a sequence of numbers of the first alphabet, in order to represent the information to be transmitted. In addition to being orthogonal, matrix H is preferentially balanced.

Abstract: The encoding method to which the present invention relates takes into account a serial turbo-encoding having at least one permutation operation which retains the divisibility of polynomial representations of sequences by predetermined polynomials and a convolutional encoding operation which includes a division by such a predetermined polynomial.

Abstract: A transmission device has labeling means adapted to map each symbol of a first alphabet to secondary digital data belonging to a second alphabet having Q symbols, Q being strictly greater than P, wherein P symbols of the second alphabet each exclusively represent one and only one symbol of the first alphabet. A coder determines redundant data belonging to the second alphabet, using coding rules that take into account the secondary digital data. A transmitter modulates a physical quantity into a series of signals each capable of taking a number P of different values, and according to transmission rules successively representing the digital data to be transmitted and the redundant data.

Abstract: The information coding device has: a first labeling means adapted to associate, with the information to be coded, K “initial” first degree polynomials, a coding means which performs a polynomial calculation: to form K “coded” sequences of P, greater than or equal to K, “coded” polynomials, the first being equal to one of the K initial polynomials and the others to the product of the preceding polynomial and a predetermined polynomial, and to form a “resultant” sequence of P “resultant” polynomials respectively equal to the sums of the coded polynomials of same rank of the K coded sequences, a second one-to-one labeling means adapted to label the points of a quadrature amplitude modulation signal constellation with the Q2 resultant polynomials, for two adjacent points of the constellation, the polynomials labeling them have one identical coefficient and the other coefficient differing only by 1 modulo Q, and a modulator for quadrature amplitude

Abstract: The invention concerns a method and device for interleaving data forming part of a transmission or reception method. More particularly, the object of the present invention is an interleaving and deinterleaving method, intended to form part of a so-called “turbocoding” method and the associated turbodecoding method, with the aim of proposing more efficient interleavers for a turbocoder, that is to say ones making it possible to obtain a greater minimum distance for the code.

Abstract: A coding device that supplied code words, the symbols of which are capable of modulating a physical quantity on a transmission channel making use of symbols of a first alphabet. The decoding of these words uses symbols of a second alphabet containing the first alphabet, the cardinal of the second alphabet being strictly greater than that of the first alphabet and not being an integer power of the cardinal of the first alphabet. The coding device has an input of the “primary” symbols belonging to the first alphabet, a processor which determines redundant symbols capable of allowing decoding of the code words formed from primary symbols and redundant symbols, by a decoder working on the second alphabet, and solves a system of equations expressing the constraints to be met so that the redundant symbols are in the first alphabet, and an output of the symbols of the code words.

Abstract: A coding method for padding K information sequences ui (i=1, 2, . . . , K) to produce K+M1 binary sequences ai (i=1, 2, . . . , K) and ci (i=1, 2, . . . , M1) so that the sequences ai are divisible by a set of K predetermined generator polynomials gi(x) (i=1, 2, . . . , K) each dividing (XN0+1) and the M1 sequences ci are obtained in a calculation involving permutations of the sequences ai (i=1, 2, . . . , K); the permutations having the property of transforming a cyclic code of length N0 with generator polynomial gi(x) to an equivalent cyclic code with a predetermined generator polynomial gij(x).

Abstract: For encoding a source sequence of symbols (u) as an encoded sequence: the source sequence (u) is divided (508) into p1 first sub-sequences (Ui), p1 being a positive integer, and each of the first sub-sequences (Ui) is encoded by means of a first circular convolutional encoding method; the source sequence (u) is interleaved (506) into an interleaved sequence (u*); and the interleaved sequence (u*) is divided (507) into p2 second sub-sequences (U′i), p2 being a positive integer, and each of the second sub-sequences (U′i) is encoded by means of a second circular convolutional encoding method. At least one of the integers p1 and p2 is strictly greater than 1 and at least one of the first sub-sequences (Ui) is not interleaved into any of the second sub-sequences (U′j).

Abstract: A device for transmitting digital data includes a selector which selects certain digital data couples which follow each other, a mapper, which, in accordance with a set of rules, maps each digital data couple selected to an amplitude couple, and a transmitter which transmits a signal in quadrature, the two components of such signal being modulated by the first and second amplitudes, respectively, of the amplitude couple. The set of mapping rules includes a rule that states that when the estimated probability that two amplitude couples will be confused, after the transmission has occurred, is greater than a certain value, then the digital data couples corresponding to the two amplitude couples have first or second digital data items whose value is the same.

Abstract: In order to encode an original sequence of binary data (u), a first padding operation (508) is performed, supplementing the original sequence (u) so that the supplemented sequence (u) is divisible by a first divisor polynomial; a first recursive convolutional encoding operation (508) is performed, using the first divisor polynomial, encoding the supplemented original sequence (u); an interleaving operation (506) is performed, permuting the binary data in the original sequence (u) by means of a specific permutation, so as to obtain an interleaved sequence (u*); a second padding operation (510) is performed, supplementing the interleaved sequence (u*) so that the supplemented interleaved sequence (u*) is divisible by a second divisor polynomial (g2); and a second recursive convolutional encoding operation (510) is performed, using the second divisor polynomial, encoding the supplemented interleaved sequence (u*).

Abstract: In the digital communication systems, devices and methods described, a transmission medium is shared by means of service messages indicating to each digital communication device whether or not that device is authorized to send on the medium once the medium is free after the service message. Certain of these messages are collective authorization-to-send messages indicating to a group of communication devices that each is authorized to send by return. When such a collective message is sent, each receiving device, when attempting to send on the medium, determines whether or not it may send in return, in accordance with a preset rule which preferably involves a random ballot.