Abstract: An electrically written memory element utilizing the motion of protons within a dielectric layer surrounded by layers on either side to confine the protons within the dielectric layer with electrode means attached to the surrounding layers to change the spatial position of the protons within the dielectric layer. The device is preferably constructed as a silicon-silicon dioxide-silicon layered structure with the protons being introduced to the structure laterally through the exposed edges of the silicon dioxide layer during a high temperature anneal in an atmosphere containing hydrogen gas. The device operates at low power, is preferably nonvolatile, is radiation tolerant, and is compatible with convention silicon MOS processing for integration with other microelectronic elements on the same silicon substrate. With the addition of an optically active layer, the memory element becomes an electrically written, optically read optical memory element.

Abstract: A long-interval grating in an optical fiber is designed to enable the making of a mode-coupling filter. In particular, it has periodic variations of the diameter of the optical fiber and a symmetry of revolution.

Abstract: The present invention relates to a multiplexer and/or demultiplexer optical component of the waveguide array spectrograph type, the component comprising an inlet coupler and an outlet coupler in a star configuration between which said array extends, the array having a first directed mean direction on departure of the waveguides of the array from the inlet coupler, and a second directed mean direction on arrival of the waveguides of the array at the outlet coupler, and presenting a directed general axis defined as being the axis passing through the centers of the couplers and on which a single positive direction is defined, and in which the first and second directed directions have respective directive angles measured algebraically from the general directed axis, which angles have the same sign.

Abstract: A process for the identification of a claimant by a verifier. The process is of the public key type, where the public exponent is equal to 3. The claimant draws at random a first exponent .alpha., calculates r=g.sup..alpha. mod n and transmits R=r.sup.3. The verifier draws at random a second exponent .beta., calculates t=g.sup..beta. mod n, calculates T=t.sup.3 mod n and h=H.sub.1 (Z), where H.sub.1 is a hash function, and calculates Z=R.sup.3 mod n. The verifier transmits to the claimant the numbers T and h. The claimant calculates Y=T.sup..alpha. mod n, verifies the result H.sub.1 (Y), calculates H=H.sub.2 (Y), where H.sub.2 is another hash function, calculates z=rS mod n, and transmits z and H. The claimant also has a secret number S equal to the modulo n cubic root of a number I deduced from its identity so that the number S verifies S.sup.3 =I mod n. The verifier verifies that H received is equal to H.sub.2 (Z) and that z.sup.3 is equal to RI mod n.

Abstract: The bits transmitted are coded according to the product of at least two systematic block codes. Iterative decoding is applied in order to determine, at each code word search step, a data matrix ({R}) and a decision matrix ({D}) used for the following step. The new decision matrix is determined at each step by decoding the lines or columns of the input matrix, and the new data matrix is determined taking into account the correction terms which increase the reliability of the decoding on each iteration. The coding and decoding circuits (17) are rendered programmable by a shortening technique allowing selection of the number k-X of non-redundant information bits per block to be coded. Known values are assigned to the other bits, the positions of which are uniformly distributed according to each dimension of the matrices.

Abstract: Following a call set-up request emitted by a terminal of a given user of a telecommunications system using a constellation of non-geostationary satellites, the terminal reserves a channel in the cell in which it is located and in neighboring cells not including all the cells it will have to cross during a predetermined time period. For each cell where a channel has not been reserved, the given user's terminal waits until it is at a predetermined distance from its point of handover into the cell, equal to the greatest distance a user can travel in the cell, before transmitting a reservation request. The call set-up request is accepted only if a condition relating to the number of other users near the given user at the time of the call set-up request is satisfied.

Abstract: A protocol for interconnection between fixed radio stations of a cellular telephony network for the transmission of management messages to manage the cellular radiotelephony network in asynchronous mode transmission or DQDB, in which geographical coordinates are assigned to each fixed radio station of the network, and a virtual-ring interconnection for any set of two neighboring stations is formed. The management messages between neighboring stations, identified on the basis of their geographical coordinates, on the virtual ring, using a self-adaptive intercommunication process are transmitted.

Abstract: A method and a device adapted to hands-free mobile radiotelephony for the optimized processing of a disturbing signal during a sound capture, on the basis of an observation signal y(t) formed of an original useful signal s(t) and of this disturbing signal p(t), the disturbing signal is estimated as a signal p(t) and the useful signal as an estimated useful signal su. An optimal filtering of the observation signal y(t) is carried out on the basis of the signal p(t) and of a minimizing of the error e(su,su) between the useful signal su and the estimated useful signal su. The estimated useful signal su and the useful signal converge towards the original useful signal s(t) for a substantially zero error e(su,su).

Abstract: A is a detachable casing capable of adapting to a computer mouse type peripheral by covering it partially. This casing comprises, firstly, at least one pressure sensor to measure the pressure exerted on this pressure sensor by an operator's hand and, secondly, linking means to address the signals coming from this sensor to the computer. The casing is inexpensive and highly ergonomical. It enables the possibilities of use of a computer to be greatly extended by increasing the number of controls performed with only one hand.

Abstract: The process consists in depositing, by chemical vapor deposition using a mixture of silicon and germanium precursor gases, a single-crystal layer of silicon or germanium on a germanium or silicon substrate by decreasing or increasing the temperature in the range 800-450.degree. C. and at the same time by increasing the Si/Ge or Ge/Si weight ratio from 0 to 100% in the precursor gas mixture, respectively.

Abstract: Disclosed are a method and a device for the convolutive encoding of blocks each formed by a predetermined number N of source data elements, wherein each of said source data elements is introduced twice into one and the same convolutive encoder implementing a generating polynomial with a period L in an order such that the two instances of introduction of one and same source data element d.sub.i are separated by the introduction of (p.sub.i.L)-1 other source data elements, p.sub.i being a non-zero integer. Also disclosed are a corresponding decoding method and device that can be applied, in particular, to the transmission of short messages, for example in radiotelephony, for satellite communications or gain computer telecommunications (Internet for example). FIG. 2.

Abstract: A method enabling a multiple sensor equalization in a radioelectrical receiver including a specified number of reception antennas, the method including the steps of estimating the transmission channel on each of the antennas; estimating the background noise component plus interference on each of the antennas on the basis of the estimation of the transmission channel; estimating the spatial correlation matrix referenced R.sub.b of the background noise component plus interferences from the received signal; computing a spatial-temporal filter formed for each discrete temporal element of the estimated multiple-sensor channel of a spatial filter; achieving a temporal filtering of the data elements on the different sensors by the spatial-temporal filter; and equalizing the signal at output of the spatial-temporal filter by one-dimensional equalization at a symbol rate deciding the symbols transmitted.

Abstract: The invention relates to a method of making a device for stabilizing a Bragg grating relative to temperature, the device being of the type comprising two materials having coefficients of thermal expansion that are far apart, the method comprising the steps consisting in:supplying a glass and a metal suitable for fixing to each other by a chemical reaction between them in an appropriate range of temperatures; andputting the glass and the metal into contact with each other at a temperature lying in said appropriate temperature range so as to fix them together.

Abstract: Millimeter-wave optical source intended for a distribution network of radio over fiber type.This source comprises a laser (2) coupled to at least one optical fiber (4) to distribute radio signals over fiber, means (12) of controlling the laser so that the latter generates a millimeter-wave carrier, and a dispersive medium (6) coupled to the laser able to shift the carrier phase and consequently an absorption peak appearing in the optical fiber.

Abstract: A metal-semiconductor-metal photodetector including an absorbent layer, a barrier layer of greater forbidden band energy on which there are deposited Schottky electrodes and a transition layer of graded composition, the photodetector including a doping plane situated in the vicinity of the join between the absorbent layer and the transition layer of graded composition.

Abstract: A method for performing electronic transactions between a card, a service provider having at least one terminal configured to accept the card and a centralized system configured to be connected to the terminal. The terminal transmits to the card a parameter M including the sum of the transaction and its identity. The card produces two signatures, a first signature (z) depending on a secret debit key (k) and on the parameter (M), this first signature being a proof that the card balance has been debited; and a second signature (y) depending on the first signature (z), the second signature being produced either by an RSA algorithm or by an interactive algorithm. The terminal checks the second signature (y) but not the first one because it is unable to recover the secret debit key (k). The terminal stores the different first signatures (proofs) (z) and the parameters (M) for the different transactions. The centralized system can collect the first signatures and the parameters.

Abstract: The present invention relates to the technological field of manufacturing semiconductor materials for optoelectronic and microelectronic components, and it relates specifically to the method of making stacks of metamorphic layers of materials having lattice mismatches of several percent between one another or relative to the substrate.

Abstract: The invention relates to a device for the reception of signals formed by a series of digital symbols corresponding to the convolutive encoding of items of source digital data comprising p cascade-connected detection and decoding modules M.sub.1 to M.sub.p, p being greater than or equal to 2, each of said modules M.sub.i including: (a) inter-symbol interference correction means supplied by a symbol input R.sub.i and delivering estimated symbols A.sub.i,1 with weighted values, (b) means for the decoding of said estimated symbols A.sub.i,1, performing operations symmetrical to said convolutive encoding and delivering decoded symbols A.sub.i,2 with weighted values, and (c) means for the computation of an item of correction information Z.sub.i+1 from said estimated symbol A.sub.i,1 and said decoded symbol A.sub.i,2, (d) said means for the correction of each of said modules M.sub.i, except for the first module M.sub.1, taking account of at least one item of correction information Z.sub.

Abstract: The present invention relates to a multiplexer and/or demultiplexer optical component of the waveguide array spectrograph type, wherein the waveguides are numbered in order of increasing optical path length, the optical path lengths of the waveguides describing a function of waveguide number which varies about a mean linear function, a difference measured between said waveguide number function and said mean linear function describing a difference function not limited to a set of two linear functions, said difference function being suitable for giving the optical component a spectral response that is square in shape.

Abstract: Process for making preforms for multicore optical fibers. According to this process, several elementary preforms are made, a first machining is performed on them such that a chosen geometric model will be obtained after they are assembled, a second machining is performed such that the assembly (11) has at least one hole (12), the preforms are assembled and an induction furnace (18) is used to fuse the preforms, while creating a vacuum in each hole.