Showing papers by "Orange S.A. published in 1990"

Device for processing echo, particularly acoustic echo in a telephone line

Abstract: The device comprises an echo cancelling circuit receiving a first signal and a second signal and a real echo between channels for producing a third signal containing the second signal and a difference between the real echo and the estimated echo. Detectors detect the echo difference and the second signal in the third signal when the level of the third signal exceeds a predetermined threshold. Circuits gain-control the adaptation in the adaptive filtration of the echo cancelling circuit in such a way as to modify the adaptation gain when the second signal is not detected and to prohibit all filtration modifications as long as the second signal is detected. For instance, for an acoustic echo in a telephone set, the echo is not processed when the third signal contains a local speech signal as second signal.

Method for the coding of a digital signal, coder and decoder to implement this method, regeneration method and corresponding regenerator utilizing pulse position modulation

Abstract: Method for coding a digital signal, a coder and decoder for implementing this method, a regeneration method and a corresponding regenerator. On each bit time, a detection is made of the possible presence of a binary pattern from any number "n" of binary patterns including at least two bits; the bit time is divided into "n" equal time intervals to which "n" temporal positions are associated; a correspondence is established between each of "n" binary patterns and each of "n" temporal positions; if one of the binary patterns is present, a pulse occupying a temporal position corresponding to the binary pattern is generated and the next detection for the possible presence of a binary pattern is made from the bit following the last bit of the binary pattern whose presence is detected.

Hard-wired micro-circuit card and transaction method between a respective hard-wired micro-circuit card and a terminal

Abstract: The invention relates to a microchip card of the type comprising: - a communication interface; - an internal memory; - a hard-wired processing unit permitting this internal memory to be addressed from the outside. According to the main characteristic of the invention, a secret internal memory area (40) is provided, not addressable from outside, and the processing unit comprises a hard-wired circuit (30) suitable for using the contents of the secret memory in order to establish a first cryptographic function (f), a series of two operands, and means reacting to the interrogation of predetermined addresses of the internal memory, accompanied by a keyword (19), by applying this keyword (19) and the output (20) of the internal memory as operands of the hard-wired circuit (30), while the output (39) of the hard-wired circuit is applied to the interface.

Device for treating echoes, particularly acoustic echoes, in a telephone line

Abstract: The device comprises an echo cancelling circuit (3) which receives a first signal (RECEIVED) and a second signal (PM), and a real echo (ECR) between routes for producing a third signal (RESIDUE) including the second signal (PM) and a difference between the real echo and an estimated echo (ECES). Sensors (2R, 2E, 41) sense in the third signal (RESIDUE) the difference between echoes (ECR-ECES) and the second signal (PM) when the level of the third signal passes a predetermined threshold. Circuits (42, 43) gain control (GADAPT) the matching in the adaptive filtering of the echo cancelling circuit (3) in order to alter the matching gain when the second signal (PM) is not sensed and to prevent any alteration of the filtering while the second signal is being sensed. For example, for an acoustic echo in a telephone set, the echo is not processed when the third signal contains a local speech signal as the third signal.

Variable rate speech coding with online segmentation and fast algebraic codes

Abstract: In several speech coding applications the constraint of fixed bit rate and frame size is not imposed. For such a situation, a speech coding system performing speech segmentation and segment coding, both with reasonable complexity, is proposed. Speech is segmented according to its statistical properties. Each class of segment is encoded by a specific algorithm using algebraic excitation codebooks. An average bit rate between 5 and 6 kb/s yields a small degradation over a 9.6-kb/s fixed rate coder. >

Wideband aperture coupled microstrip subarray

Abstract: A broadband microstrip patch was designed for potential use as an element in a spaceborne multibeam antenna Its integration in a subarray yields high polarization purity This structure yields broad bandwidth and low cross-polarization A subarray of such an element presents a reduced cross-polar level This type of subarray can be used in a spaceborne (satellite) multibeam array with a maximum deflection of just a few degrees >

Compression apparatus for transformed digital audio signal with adaptive quantization based on psycho-acoustic criterium

Abstract: The field of the invention is that of digital audio signal compression. The invention applies in particular to the transmission of sound signals on digital channels, and to devices for storing digital sound signals. The invention relates to an apparatus for compressing an audiodigital signal, using an apparatus for allocating bits which are available for transmission or storage of the signal, driving means of adaptive quantisation of the signal, so as to permit a significant reduction in the throughput whilst preserving to the maximum the quality of the starting signal. According to the invention, the apparatus comprises means (16) of allocating a specific number of bits in order to express the coefficients of each frequency band of a transformed audiodigital signal (12) as a function of an auxiliary item of information (19) corresponding to a description of the spectrum of the said signal (12), the said apparatus being informed by means (14) of prior elimination of spectral components of the said transformed signal (12) as a function of a psycho-acoustic criterion.

Prepaid rechargeable memory card

Abstract: The invention relates to memory cards and more particularly those which are used as prepayment means in installations for the dispensing of products or services. According to the invention, it is proposed to make the memory rechargeable by means of a credit counter (CPC) incrementable from outside the card (terminal CR), and a comparator (COMP) which compares the content of this counter with that of a page counter (CPP); the page counter records the number of pages of P account units already consumed. An end-of-credit signal is transmitted to an outside terminal (ST) when the content of the page counter reaches the content of the credit counter. Security against the fraudulent recharging of the card is obtained by means of an algorithm involving the content of the credit counter and an identification number contained in the card.

Low-temperature DC characteristics of pseudomorphic Ga/sub 0.18/In/sub 0.82/P/InP/Ga/sub 0.47/In/sub 0.53/As HEMT

Abstract: A high-gap strained GaInP material chosen to increase Schottky barrier height on InP is discussed. This material has been used for the first time in high electron mobility transistor (HEMT) fabrication on InP. For these devices the best g/sub m/ of a 1.3- mu m gate HEMT is 300 mS/mm. Transistors of 3- mu m gate length are studied at low temperature (100 to 293 K). Their DC electrical characteristics improve upon cooling. The best improvement is measured at the lowest temperature (+54% for g/sub m/ at 105 K). The structure is stable and does not present any g/sub m/ or I/sub ds/ collapse at low temperature, unlike AlGaAs/GaAs heterostructures. >

Mobile application part design principles

Abstract: This paper describes the principles which have been followed to specify the Mobile Application Part (MAP) protocol which is intended to support the pan-European digital cellular mobile system (GSM system). This was the first non-call related protocol to be standardized. The first part of the paper describes which services are requested from the various layers of CCITT Signaling System N7 and how they are used. In the second part the choices made for the design of this specific application protocol are explained. The interworking issues are then highlighted and finally, the evolution of such a protocol to support other services is dealt with.

High-speed half-flash type analog/digital converter

Abstract: An analog/digital converter supplying logic words constituted by P high order bits and Q low order bits, comprises: a divider (2), 2P high weight comparators (5), 2Q low weight comparators (11), and a selector (14). The high weight comparators have their second inputs (E21) enabled by the clock signal (H) and their first inputs (E11) enabled by the reverse clock signal (H*). The low weight comparators have their first inputs (E12) enabled by the reverse clock signal (H*) and their second inputs (E22) enabled by the clock signal (H).

Module and optical fiber cables connecting-box

Abstract: The field of the invention is that of connection boxes for fibre optic cables, also known by the name splice organisers. … The objective is to provide compatibility with all types of cables and to limit the transfer lengths of the fibres between the zones for fanning out the cables and the cassettes for connecting and coiling up the lengths of excess fibre, in order to provide great stability and reliability of the connections and thus to enable the expensive and complicated fibre-tubing operation to be eliminated. … According to the invention, the module comprises a support plate (11) defining on at least a portion of its surface a protected space (10) for extension of the sections for transferring the fibres, the said support plate (10) comprising, on the one hand, a set of aligned and separated means (21, 22, 23) for the securing of the external jacket, the peripheral reinforcements and the central strength member respectively of each cable (1, 2, 3, 4) and, on the other hand, at least one cassette (24) for coiling up and connecting the fibres which has guided articulation and is disposed so as to limit the transfer length and the displacement travel of the said sections for transfer or guided displacement of the said articulated cassette (24). … …

Dismountable and air-transportable antenna for two-way telecommunications with a satellite

Abstract: The antenna is preferably of the offset type and comprises plural thin and separable parabolic elements jointed into a parabolic reflector, and several substantially rectangular separable panels assembled into a prismatic lattice frame for supporting the reflector. The panels are substantially perpendicular to the lower base of the lattice and have curved upper edges formed in a duplicate mould according to the reflector and separable from the reflector elements. The antenna also comprises a telescopic elevation angle lifting mast and a circular aximuth positioner, both jointed to the frame and dismountable. The dismounted antenna is transportable in the form of standardized packages in the hold of long-distance airliner.

Process for searching for synchronization on reception of a spread spectrum modulated signal

Abstract: In a phase demodulator is received a signal of which the carrier is phase-modulated by a digital pseudorandom sequence itself phase-modulated by a data signal. A frequency close to that of the carrier is locally modulated by a sequence identical to the received sequence. The received and local signals are mixed into a filtered signal with an intermediary frequency band. A repetitive double integration step of the signal filtered into an integrated signal is used and is compared with a threshold in order to quantify the correlation between the received and local signals. Firstly, the local frequency varies according to a few discrete values spread over the uncertainty range of the carrier corresponding to intermediary frequencies in the vicinity of the filtering band. At each discrete frequency value, integration steps are carried out for half-bit local frequency shifts. Synchronization of the sequences is acquired in response to an integrated signal exceeding said threshold at the end of an integration step. Then, the value of the carrier frequency is estimated by the average of numerous discrete local frequencies corresponding to favorable integration steps and included in a band centering on the frequency found during synchronization of the sequences. The invention also relates to the closed-loop controlling of the amplification gain in correlators of the demodulator.

Telephone arrangement for remote loading of telephonic subscription data from an autonomous station

Abstract: In response to a call request (LID) emanating from the autonomous station (SP) and in the presence of a loading request signal, the control means (UTF) investigate all the telephone subscription data relating to the autonomous station (SP) as well as that indicating the remote-loading order. The enciphering means (CDF) encipher, with the aid of the special key (EPID), those which are secret (PIN). The processing means (UTF) allow the transmission in clear of the telephone subscription data which are public, as well as those which are secret and so enciphered, to the said autonomous station (SP) as a function of the remote-loading order. At the level of the autonomous station (SP) the deciphering means (CDP) decipher the telephone subscription data which are secret, enciphered and so received with the aid of the special key (EPID), and the processing means (UTP) store the subscription data which are public so transmitted in clear, and secret so deciphered in the memory of the autonomous station (SP).

Tuned helical antennae consisting of two quadrifilar antennas fit into each other

Abstract: The present device relates to a novel antenna structure offering a near hemispherical radiating pattern and capable of offering a relatively wide pass band so as to be able to clear therein two neighbouring sub-bands or else a single, wide transmission band. The antenna is of the type comprising a quadrifilar helix (11) consisting of two bifilar helices arranged orthogonally and excited in phase quadrature, and includes at least one second quadrifilar helix (12) coaxial and electromagnetically coupled with the said first quadrifilar helix (11). Preferred application to L-band communications between geostationary satellites or in transit with mobiles equipped with such antennas.

Arrangement for echoprocessing, especially acoustic, in a telephone line

Abstract: The device comprises an echo cancelling circuit (3) which receives a first signal (RECEIVED) and a second signal (PM), and a real echo (ECR) between routes for producing a third signal (RESIDUE) including the second signal (PM) and a difference between the real echo and an estimated echo (ECES). Sensors (2R, 2E, 41) sense in the third signal (RESIDUE) the difference between echoes (ECR-ECES) and the second signal (PM) when the level of the third signal passes a predetermined threshold. Circuits (42, 43) gain control (GADAPT) the matching in the adaptive filtering of the echo cancelling circuit (3) in order to alter the matching gain when the second signal (PM) is not sensed and to prevent any alteration of the filtering while the second signal is being sensed. For example, for an acoustic echo in a telephone set, the echo is not processed when the third signal contains a local speech signal as the third signal.

Radio system for data transmission to a low cost passive terminal

Abstract: Le systeme radio selon l'invention comprend une station centrale (1) et une station terminale passive (2). The radio system according to the invention comprises a central station (1) and a passive terminal station (2). Des premier et second signaux de donnees (D12, D21) sont transmis entre des unites de traitement de donnees (U1, U2) respectivement connectees aux stations centrale et terminale. First and second data signals (D12, D21) are transmitted between data processing units (U1, U2) respectively connected to the central and terminal stations. Le systeme radio est essentiellement caracterise en ce que la station terminale comprend un meme circuit (22) de faible cout associe a une antenne plane carree (20) pour detecter l'amplitude d'une premiere micro-onde incidente (PA) emise par la station centrale afin de recuperer le premier signal de donnees pour produire en retour une micro-onde modulee en phase (PP) par le second signal de donnees par retroreflexion d'une seconde micro-onde incidente (P). The radio system is essentially characterized in that the terminal station comprises a single circuit (22) low cost associated with a square planar antenna (20) for detecting the amplitude of a first incident microwave (PA) emitted by the central station to recover the first data signal to produce in return a microwave phase modulated (PP) by the second data signal by a second retroreflection incident microwave (P). Cette seconde micro-onde incidente (P) est emise par la station centrale vers l'antenne plane carree de la station terminale. This second incident microwave (P) emitted by the central station to the square planar antenna of the terminal station. La station terminale est de conception tres simple et peu encombrante et peut etre incluse ainsi que l'unite de traitement de donnees correspondante dans une carte a puce sans contact. The end station is very simple and compact design and can be included and the corresponding data processing unit in a contactless smart card.

Terminal for sound and visual communication with improved adjustments

Abstract: Terminal for sound and visual communication comprising a case, a picture camera, a viewing screen, a microphone and a loudspeaker, and interfacing and sound and image information encoding/decoding means combining with these elements for communication with another terminal of the same type via a digital transmission network. … The terminal is characterised by the following combination:… adjustment means for at least one picture parameter,… manual control means able to generate information for adjusting the parameter(s), and… means of switching between a local adjustment mode, in which the said adjustment information is applied to the said adjustment means, and an interactive adjustment mode, in which the said adjustment information is sent to the said other terminal across the digital network in parallel with the said sound and image information, and in which adjustment information received from the said other terminal, likewise across the digital network and in parallel with the sound and image information, is applied to the said adjustment means. … Application to improving the comfort of users of videophony. … …

Emulators of a digital network terminal and bus test and measurement systems

Abstract: An emulator according to the invention essentially comprises a central-processing unit (1050), frame multiplexing and demultiplexing circuits (1054 and 1055), line transmission and reception circuits (1056 and 1057), means of interfacing with an external system (1051, 1052 and 1053), and a time base (1059). The emulator transmits downward test frames (TD) and analyses upward test frames (TM) transmitted in response by terminal devices. The information contained in the frames is processed by the central-processing unit so as in particular to determine the condition and quality of various links established with the terminal devices. The emulator is more particularly designed to be integrated in a bus testing and measuring system according to the invention. The system comprises a main piece of equipment connected to a bus and which includes the emulator and terminal-simulation devices. Circuits for measuring resistance, electrical isolation, and crosstalk, as well as a circuit for detecting a perturbing potential are also included in the system and permit very full testing and measurement of the characteristics of the bus.

Method and system of smoothing and control of asynchronous time communications

Abstract: The invention smooths asynchronous time communication outputs which are formed by cells received from an incoming synchronous time multiplex(XE) in order to supply an outgoing asynchronous time multiplex(XS). Each incoming cell is stored in a buffer memory (MT) with an address (Add) corresponding to the actual time when that cell will be transmitted (t) on the outgoing time multiplex (XS). The address (Add) of the cell entering the buffer memory (MT) is determined by calculating a function of the theoretical minimum time period (pm) between outgoing cells. The searching in the buffer memory (MT) is for the first free address (Add) corresponding to an actual transmission time (t) which is chronologically beyond the next theoretical transmission time (tso). The actual time for outgoing transmission is determined as a function of a period (pm) allotted to the communication to which the incoming cell belongs. The period (pm) corresponds to the theoretical minimum time period between transmitted cells in the outgoing synchronous time multiplex (XS).

Service creation for the intelligent network

Abstract: The objective of this paper is to describe one of the key ingredients for introducing services on an intelligent network, the service creation environment. nis environment will facilitate all the phases of service ereation: the specification or modification of services, their development, their test and validation and finally their deployment in the network The paperfirst gives an overview of FRANCE TELECOM's intelligent network and then outlines the structure of its service creation environment. Finally, in order to illustrate the approach, it focuses on two elements of this environment. Thejrst element is a tool that allows the designer to define the service data and the second one is a tool to define the service logic. INTRODUCTION One of the aims of the "Intelligent Network" is to allow for rapid and easy service introduction. To this end, the telecommunication network (PSTN, data network, ...) must be organized so as to provide an infrastructure that speeds up the introduction of new servicts. But in addition, it is also nccessBly to facilitate their definition. This can be pcrfonned by means of a service creation environment helping to describe service logic and service data. The final objective is to be able to introduce a complex new service within a few months, a simpler one within a few weeks and to modify any service within a few days. For instance, if the network is the PSTN (Public Switched Telephone Network), a complex servicx. could be PVN (Private Viaual Network) and a simpler senice could be Tclevoting. 1. OVERWEW OF FRANCE TELECOM'S INTELLIGENT NOWORK FRANCE TELECOM's intelligent network is based on two main service-independent functional entities: the "Point de Commande des Services" (PCS) and the "Commutateur d'Acc& aux Services" (CAS, close to the SSP). The PCS performs the "intelligent" part of the service, as it knows both the service logic and the service data. The PCS function may be part of a network node (for instance, an exchange in the PSTN) or outside the network node in an intelligent node. The CAS function is always located in a network node. It allows the node to perform a generic l i t of elementary operations under the control of the PCS function. The intelligent node and the network node hosting the CAS function arc not the only elements of FRANCE TEECOM's intelligent network (see Fig. 1). The other service-independent elements arc: . The INDB (Intelligent Network DataBase). It is an intelligent node that may be accesscd only by PCSs. The interface is based on a Query/Response type of dialogue, . The Charging Center, a machine that collects data about the communications from PCS or CAS and that will be Connected to FRANCE TELECOM's future integrated billing system, =GATE. The IP (Intelligent Peripheral). This is a machine that provides resources that are not located in network nodes. Ips are controlled by CAS and PCS. The signalling network (SS7 network for the PSTN). It allows for the interconnection of intelligent nodes, network nodes, INDB and Ips. *

Manufacturing process of mesa SOI MOS transistor

Abstract: A method for manufacturing a MOS transistor formed in a silicon block on insulator with convex rounded up edges, initially consisting in etching the block in a thin layer of silicon on insulator (SOI). In this method etching of the block comprises the following steps: forming at the position where it is desired to obtain the block a mask layer portion (3) having a thickness slightly higher than that of the SOI; depositing a second silicon layer (11) having a predetermined thickness; and anisotropically etching silicon until said insulator is apparent outside the mask layer portion.

Method to control the thickness of an antireflection coating and implementation installation

Abstract: Method to control the thickness of an antireflection coating According to the invention, the semi-conductive structure (14) is fed with a constant current (16) and the voltage (24) is measured at its terminals This voltage passes through a maximum when the reflectivity of the antireflection coating passes through a minimum Application for the embodiment of semi-conductive lasers

Electroencephalographic signal processing method and apparatus therefor

Abstract: The method permits determination of the stages of sleep during the period when the signal is picked off. The EEG signal is chopped into time slices of the same duration; each slice of the signal is digitally sampled in order to obtain successive blocks of N samples; for each block i, M normalised correlation coefficients Ri,k are determined, M being very much smaller than N; for each block i, the distances D(i,j) are calculated between the coefficients Ri,k of the current block and the coefficients Rj,k of the centres of gravity of the already-existing j classes; the minimum D(i,p) of the D(i,j) is selected; block i is assigned to class p if D(i,p) is lower than a defined threshold, while updating the centre of gravity of the class, while a new class is created if D(i,p) is greater than the defined threshold; and each class is assigned to the closest stage from the point of view of energy distribution between frequency bands.

Method and device for electrooptical modulation using the low energy oblique transition in a strongly coupled superlattice

Abstract: According to the invention, a light beam is injected into a strongly-coupled superlattice and applied to the latter is an electric field (E) whose amplitude is varied over time so as to vary the intensity of the beam. The latter is injected in a manner parallel to the plane of the layers of the superlattice which guides the beam thus injected. The electric field is small and applied along the growth direction of the superlattice, which causes the appearance of a low-energy oblique transition (TB) in a wavelength range where the superlattice is transparent in the absence of electric field. The superlattice is such that the wavelength (l1) of the light beam is confined to this range. Application to optical telecommunications.

Acoustooptical device having a superlattice as interaction medium

Abstract: Ce dispositif comporte un milieu d'interaction photoelastique entre un faisceau lumineux incident (28) et au moins une onde acoustique ainsi que des moyens (4, 6) prevus pour engendrer l'onde acoustique. This device comprises a photoelastic interaction medium between an incident light beam (28) and at least one acoustic wave and means (4, 6) adapted to generate the acoustic wave. Le milieu d'interaction est un super-reseau (18) qui est transparent au faisceau lumineux et dont la periode est voisine d'un multiple entier de la moitie de la longueur d'onde du faisceau lumineux dans le super-reseau. The interacting medium is a superlattice (18) which is transparent to the light beam and whose period is close to an integer multiple of half the wavelength of the light beam in the superlattice. Application a la fabrication de modulateurs et de deflecteurs acousto-optiques. Application to the manufacture of modulators and acousto-optic deflectors.

Digital signal encoding method, encoder and decoder for carrying out the method, regeneration method and regenerator therefore

Abstract: Method of encoding a digital signal, encoder and decoder for carrying out this method, and method of regeneration and regenerator therefor. With each bit period, the possible presence is detected of a binary pattern from an arbitrary number n of binary patterns comprising at least two bits; the said bit period is divided into n equal time intervals with which are associated n time positions; a correspondence is established between each of the n binary patterns and each of the n time positions; in the event that one of the n binary patterns is present, a pulse is generated occupying a time position corresponding to the said binary pattern and the next detection of possible presence of a binary pattern is carried over from the bit following the last bit of the said binary pattern whose presence was detected. Application to digital transmission.

Wavelength-stabilized semiconductor laser

Abstract: Wavelength-stabilized semiconductor laser in which a crystal (20) doped with rare earth ions is disposed in the cavity of the laser between the amplifier medium (10) and a mirror (22). Transmission is effected on a transition of the rare earth ion.

Semiconductor optical amplifiers

Abstract: Semiconductor laser amplifiers have now proved their ability to improve the performance of single-mode fiber communication systems, at least in the laboratory stage. After a brief background review of optical amplification in communication systems, the principle of operation and main device characteristics of semiconductor optical amplifiers are examined. Some recent examples of use in fiber communication systems are also reviewed.