Showing papers by "Orange S.A. published in 1996"

Improved decoding with the SOVA in a parallel concatenated (Turbo-code) scheme

Abstract: We show that the soft output of the soft-output Viterbi-decoder (SOVA) suffers from two distortions. Firstly, for bad channels the reliability information of the decoder output is too optimistic. The output can be considered as being multiplied by a factor, that depends on the current bit-error-rate (BER). To become closer to the true log-likelihood ratio the output has to be normalized. Secondly, the soft-output of the SOVA-when used in Turbo decoding-is effected by a correlation between the so called extrinsic and intrinsic information. Since the extrinsic information is fed forward to be the a-priori information in the next decoding stage and is treated as being uncorrelated with the systematic-information, a correcting term has to be introduced in order to compensate this correlation. We show how these distortions can be corrected and we apply the correcting measures on the SOVA that is used as component decoder of a Turbo-code scheme. Finally, we provide simulation results that illustrate the gain due to normalizing the extrinsic information and exploiting the correlation in the soft output.

Process for making a payment using an account manager

Abstract: The present invention relates to a process for making a payment using an account manager or kiosk, the process guaranteeing the payment of the supplier and the anonymity of the customer. A customer (U) withdraws from his bank (B) a sum in the form of "blind" electronic coins or cash, deposits the latter in one or more anonymous accounts in a kiosk (K) and finally uses said account or accounts for paying suppliers of goods or services (SA). The invention has application to streamline and voice telepayment.

A Rational Agent as the Kernel of a Cooperative Spoken Dialogue System: Implementing a Logical Theory of Interaction

Abstract: We present the basic components of ARTIMIS, a rational agent based on the implementation of a formal theory of interaction. This theory involves a set of generic axioms which models, in a homogeneous logical framework, principles of rational behaviour, communication, and cooperation. It thus supports the rational unit of an autonomous communicating agent, which, in our case, is the kernel of a cooperative spoken dialogue system. It is expressed in a first-order (multi)modal logic of mental attitudes (belief, uncertainty, and intention) and actions. The implementation consists of an inference engine, which is a theorem prover, specifically designed to reason using the axioms and rules of this kind of logical theory in their syntactical form.

Monolithic sensor of fingerprints

Abstract: An electronic fingerprint sensor works by the detection of pressure, the ridge lines of the finger exerting a greater pressure than the valleys. The sensor has a matrix of pressure microsensors and electronic control and signal-processing circuits. It is made in an entirely monolithic form, according to techniques for the making of electronic circuits (deposition of thin layers, photo-etching, doping and thermal processing), both for the pressure detection part and for the signal-processing and control part. The matrix-type pressure sensor uses either piezoelectric resistors lying on an insulator layer stretched above a cavity or a variable capacitor or a microcontactor.

Customized storage, high voltage, photovoltaic power station

Abstract: The present invention relates to a customized storage, high voltage, photovoltaic power station, having at least one photovoltaic solar module and a customized storage device.

Monolithic integration of multiple-quantum-well lasers and modulators for high-speed transmission

Abstract: Monolithically integrated single frequency lasers and electroabsorption modulators are attracting considerable interest as optical sources for long-haul and high-bit-rate fiber-optic links. Their frequency chirpless nature has indeed allowed nonreturn-to-zero (NRZ) transmission beyond the chromatic dispersion limit. They also offer a great potential as soliton pulse generators. This paper discusses the many integration schemes devised for their realization with particular emphasis on the identical active layer (IAL) approach. Recent progress in their high-speed applications is reported.

The UV-induced refractive index grating in Ge: preforms: additional CW experiments and the macroscopic origin of the change in index

Abstract: Bragg gratings have been written within MCVD germanosilicate preform slices using CW laser light at 244 nm. Afterwards, scanning light interferometry was used to perform a 3D imaging analysis of the sample surface topography. The results show that the same process (namely densification) pointed out in a previous work in which we used UV pulsed exposure of preform slices is also active here. A simplified model which assumes that the UV-induced periodic corrugations result from both permanent and elastic strains, is presented. This model accounts not only for a large part of the measured refractive index change but also for the localization of the UV-induced birefringence along the grating wavevector. It also gives a satisfactory interpretation of the observations made by Fonjallaz et al, according to whom grating inscription within a germanosilicate fibre increased the axial tensile core stress.

Method of controlling handover in a multicellular radio communications network, and speed estimation methods relating thereto

Abstract: In a multicellular radio communications network, when a mobile station satisfies a criterion for automatic intercellular handover from a source cell to a target cell, the speed of movement of the mobile station with respect to the base station of the target cell is estimated on the basis of the measured levels of the signal which the mobile station has received from this base station before the handover criterion is satisfied. Depending on the layers of the cells concerned, it is then possible to take account of this speed estimate in order to decide whether or not to trigger intercellular handovers.

Heavy traffic analysis of a storage model with long range dependent On/Off sources

Abstract: We consider a fluid queueing system with infinite storage capacity and constant output rate offered a superposition ofN identical On/Off sources, where the ratio of input to output rate is small. The On and/or Off periods have heavy tailed distributions with infinite variance, giving rise to Long Range Dependence in the arrival process. In the limit of a large number of sources and high load, it is shown that the tail of the stationary queue content distribution is Weibullian, implying much larger queue contents than in the classical case of exponential tails. Noting that similar results were recently found by I. Norros for a storage system input by a Fractional Brownian Motion, we then show how the two models are related, thus providing a further physical motivation for the Fractional Brownian Motion model.

A new global finite element analysis of microwave circuits including lumped elements

Abstract: A new fullwave global analysis of complex inhomogeneous microwave structures including passive or active, linear or nonlinear lumped elements is presented. For a given structure, only one electromagnetic simulation of the distributed part, by a three-dimensional (3-D) finite element method using edge elements, is needed corresponding to the insertion of variable lumped elements placed at the same position. Simulation results of various test cases, containing either resistor, diode, or active component, are compared with those provided by a commercial circuit analysis software or with measurements results. Our validated electromagnetic simulator is then used for analyzing a planar balanced mixer operating in the millimetric range.

System of secured payment by the transfer of electronic money through an interbank network

Abstract: A system of payment by the transfer of electronic money and especially of electronic cheques with blind signatures comprises an interbank compensation unit, an interbank network, and a verification unit. The interbank compensation unit permits the transfer of electronic money between multiple bank units in payment of amounts owed therebetween arising from the electronic cheques. The interbank network links the interbank compensation unit to the multiple bank units, and enables the transfer of electronic cheques from a payment terminal to the interbank compensation unit. The verification unit is linked to the interbank compensation unit, and is capable of verifying the authenticity and the non-reutilization of electronic cheques which have already travelled through the interbank network after a first payment.

Construction of a multicarrier signal

Abstract: A multicarrier signal to be transmitted to digital receivers, particularly in a non-stationary transmission channel, corresponding to the frequency multiplexing of a plurality of elementary carriers each corresponding to a series of symbols is described, wherein two consecutive symbols are separated by a symbol time τ0. The spacing ξ0 between two adjacent carriers in the signal is equal to half the reciprocal of the symbol time τ0 and each carrier is subjected to spectrum formatting filtering with a bandwidth which must exceed twice the intercarrier spacing ξ0, and selected so that each symbol is highly concentrated in the time and frequency domain. Methods for transmitting and receiving such a signal are also described.

Optical add-drop multiplexer using optical circulators and photoinduced Bragg gratings

Abstract: This multiplexer adds to a group of optical signals, whose wavelengths belong to a group of wavelengths (λ1 . . . λN) and drop from said group of signals at least one optical signal having a given wavelength, chosen from within the wavelength group and comprises at least one optical circulator (C1, C2) having an input for receiving the group of signals and an output, an optical selection means (MS) coupled, on one side, to the circulator and which comprises at least one photoinduced Bragg grating (R1 . . . RN), said photoinduced Bragg grating being associated with the given wavelength and which can be in a first state, where it reflects the signal having said given wavelength and where it transits signals having a wavelength different from the given wavelength or optionally in a second state where it transmits all the signals, and a means (MC) for the control of said selection means (MS) for placing the grating in said second state, the selection means cooperating with each optical circulator for adding and dropping the optical signal or signals. Application to optical telecommunications.

Effective human-computer cooperative spoken dialogue: the AGS demonstrator

Abstract: We describe a spoken dialogue system based on a generic specification of a cooperative communicating rational agent. We present some theoretical and practical aspects of the overall approach, along with the speech-specific and natural language related issues raised by the effective implementation of the system. An account is also given of an evaluation of the system with naive users on the task of voice services directory (AGS) inquiry.

Reconfigurable device for insertion-extraction of wavelengths

Abstract: This device includes optical add-drop multiplexers (M1 to M2) each having a band-pass filter. An optical switch (C1) has outputs connected to the multiplexers. An optical coupling (C2) has inputs connected to the multiplexers. The device is useful in optical communications.

Process and device for creating comfort noise in a digital speech transmission system

Abstract: A process and a device for creating comfort noise for discontinuous speech transmission in which, following the end of each detected active period, a silence descriptor frame is generated as a set of parameters describing the comfort noise. For every successive current inactive frame, the frequency spectrum is analysed and then compared with a reference spectrum stored previously. Upon identity of the reference frequency spectrum and the current frame spectrum, no new silence descriptor frame is transmitted. Upon absence of identity of these spectra, a new silence descriptor frame is transmitted.

Process for electrical insulation in microelectronics, applicable in narrow cavities, by deposition of oxide in the viscous state and corresponding device

Abstract: The invention relates to a process for electrical insulation of conductive or semiconductor materials of a substrate, characterized in that it comprises at least the following steps: (a) at least one so-called conformal layer of insulating oxide is deposited on the predetermined regions of the substrate to be insulated; (b) a layer of planarizing oxide precursor is deposited on the predetermined regions by chemical reaction in plasma phase of a tetraalkylsilicate and of hydrogen peroxide; (c) at least one layer of insulating oxide is deposited on the predetermined regions; and (d) a conversion annealing operation is carried out. It also relates to the semiconductor devices and integrated-circuit elements having insulated narrow cavities.

Miniature microstrip stepped impedance resonator bandpass filters and diplexers for mobile communications

Abstract: Miniature microstrip stepped impedance resonator bandpass filters and diplexers for satellite mobile communications have been developed. A very high dielectric constant substrate (/spl epsiv//sub r/=89 and h=2 mm) is used. Experimental results show that an unloaded half wave resonator quality factor as high as 400 at 1.5 GHz, with such substrate, may be possible. The merit of this circuit lies in the simplicity of design procedure, the possibility of developing this filter with quite a variety of high dielectric constant substrate materials and the simplicity of simulation with most commercial software packages. A four resonator bandpass filter with 35 MHz bandwidth at 1.55 GHz was designed and implemented with this substrate. Based on this filter, a diplexer which meets satellite mobile communications performance has been developed. Experimental results are in good agreement with theoretical predictions.

Alternating phase-shift generation for complex circuit designs

Abstract: One of the main challenges for the industrialization of the alternating phase shift mask technique is the geometrical design of the phase shifters. The problem is complex and software development is required to achieve automation. This data preparation is necessary in order to apply the most powerful optical enhancement technique, the alternating PSM, to the gate lithography of logic designs. After the implementation of an algorithm, very promising on small flat geometrical designs of a few hundred transistors, it has been decided to test this software on complete circuits. This paper deals with the issues associated with alternating pattern generation on complex circuits. In particular, the use of layout hierarchy is essential to obtain an acceptable amount of manual intervention and computer processing time. There are two kinds of limitations to this global approach. First, the overlapping or the proximity of cells in the hierarchy may not be compatible with a cell-by-cell generation of phase shifters. Secondly, some local design configurations may be difficult to phase shift. The question is: `is the number of occurrences of such cases manageable?' This presentation is illustrated by our experience on a multiplier design of about 15000 transistors, created using a standard cell library in 0.25 micron technology. This work shows that the theoretically difficult cases of layout hierarchy or geometrical design are not critical in practice. In particular, the design method based on standard cell libraries creates a hierarchy which is very favorable to our approach. This article presents a method for the alternating pattern generation on complex circuits which is based on two main points: first, on a software able to generate alternating phase shifters on small flat cells, and secondly, on the advantage of using layout hierarchy.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Ring network for transmitting wavelength-multiplexed informations

Abstract: This ring network for wavelength-multiplexed information transmission. comprises two optical fibres (F1, F2) passing through nodes (N1 to N4) of the network and traversed in the opposite direction by informations, electronic add-drop multiplexers (ME1 to ME4) or ADM, each ADM supplying information to other ADM's, of the network at given wavelengths and optical add-drop multiplexers (M01 to M04) or OADM, each OADM adding to the fibres the informations from the associated ADM and extracting from said fibres the informations intended for said ADM. Application to optical telecommunications.

Optical component adapted to monitor a multiwavelength link and add-drop multiplexer using this component, application to optical networks

Abstract: Optical component adapted to monitor a multiwavelength link for use as an add-drop multiplexer in optical networks. The optical component includes an input fiber (68) for transmitting signals of different wavelengths, a diffraction grating (70) for dispersing these signals on several orders of diffraction, fibers (72, 74, 76 and 78) for recovering the dispersed signals corresponding to a given order of diffraction, and fibers (79, 80, 82, and 84) for recovering the same signals but corresponding to another order of diffraction so as to monitor the state of these signals.

Method to simulate the acoustical quality of a room and associated audio-digital processor

Abstract: A method for the simulation of the acoustical quality produced by a virtual sound source and for the localizing of this source with respect to one or more listeners, and one or more original sound sources. This method consists in: 1) fixing values of perceptual parameters defining the acoustical quality to be simulated and values of parameters defining the localization of a virtual source, 2) converting these values into a pulse response described by its energy distribution as a function of the time and the frequency, 3) carrying out a context compensation so as to take account of an existing room effect, 4) obtaining an artificial reverberation from elementary signals so as to achieve a virtual acoustic environment in real time and control the localizing of the virtual source. This method can be used to modify sound signals coming from a real source, or to create sound effects on recording media. An acoustic virtual processor which enables implementation of this method comprises a signal processing "room" module that enables the obtaining of an artificial reverberation and a signal processing "pan" module enabling the controlling of the localization and the movement of the sound source and that carries out a format conversion into another reproduction mode. The acoustic virtual processor can be used to fit out all types of entertainment halls or games halls.

High isolation, optical add-drop multiplexer

Abstract: According to the invention, a first band-pass multidielectric filter (F1) receives optical signals, transmits at least one of them and reflects the untransmitted signals. An adding means (F2) inserts among them at least one other optical signal. A photoinduced Bragg grating filter (R) receives the signals reflected by the first filter and transmits them to the adding means and reflects any optical signal of the same wavelength as the signal transmitted by the first filter and which is liable to exist among the signals reflected by it. Application to optical telecommunications.

Fixing, earthing and sealing device for optical cables

Abstract: Device for fixing, earthing end sealing the end of an optical cable, including at least one optical module, an outer jacket, especially made of relatively deformable plastic, having a cylindrical general shape, freely surrounding the optical module consisting of a set of adjacent fibres which are independent or preferably housed in a confinement sheath, and at least one reinforcing element having a high mechanical strength, in particular a high tensile strength, in order to take up and absorb the forces exerted on the cable without transferring them to the optical module, wherein it includes an immobilizing member operating by clamping the jacket from outside the latter, at least one hollow protective sealing plug capable of being placed around and possibly crimped onto a part of the reinforcing element that extends from the front end of the jacket which has been cut beforehand in order to strip the optical module, this plug including a flange, possibly protruding, bearing against a plane surface made on the end of the jacket, and a locking assembly for clamping over the plug, this locking assembly being formed by two oppositive jaws which mutually interact, closing together onto the external surface of the plug in a diametral plane passing through the axis of the latter, means being furthermore provided for closing together the locking assembly for clamping over the plug with respect to the member for immobilizing the jacket, so as locally to compress the latter by means of the flange of the plug, thereby achieving sealing with respect to the outside of the reinforcing element extending into the thickness of the sheath, parallel with its longitudinal axis.

Relation between quantum and geometric dimensionalities in molecular nonlinear optics: beyond the two-level model for anisotropic systems

Abstract: The nonlinear optical susceptibilities of two- or three-dimensional molecular systems exhibit variable anisotropic features depending on their structure and substitution pattern. We show that appropriate geometric (e.g. tensorial) considerations combined with an n-level quantum model (n≥3) are able to account for such nonlinear anisotropy as rigorously defined in an invariant spherical formalism by extension of classical linear anisotropy. We call on two kinds of experiments to investigate these properties: firstly, variation of the incident polarization (VIP) in harmonic light scattering (HLS) experiments is being performed to sort out individual tensorial components of the quadratic hyperpolarizability β tensor; secondly, wavelength dependence studies in coherent second harmonic generation (SHG) from poled thin film media are shown at a preliminary stage to be able to designate those excited states responsible for the nonlinear anisotropy.

Algebraic code-excited linear prediction speech coding method

Abstract: The method uses the technique of CELP coding with algebraic codebook The search for the CELP excitation includes a calculation of certain components of the covariance matrix U=H T ·H where H denotes a lower triangular Toeplitz matrix formed on the basis of the impulse response of a compound filter made up of synthesis filters and of a perceptual weighting filter The memory-stored components of the covariance matrix are only those of the form U(pos i ,p,pos i ,p) and those of the form U(pos i ,p, pos j ,q), pos i ,p and pos j ,q respectively denoting position i and position j for the pulses p and q in the codes of the algebraic codebook

Method for linear predictive analysis of an audiofrequency signal, and method for coding and decoding an audiofrequency signal including application thereof

Abstract: The linear predictive analysis method is used in order to determine the spectral parameters representing the spectral envelope of the audiofrequency signal. This method comprises q successive prediction stages, q being an integer greater than 1. At each prediction stage p(1≦p≦q), parameters are determined representing a predefined number Mp of linear prediction coefficients a 1 p , . . . , a Mp p of an input signal of the said stage. The audiofrequency signal to be analysed constitutes the input signal of the first stage. The input signal of a stage p+1 consists of the input signal of the stage p filtered with a filter with transfer function ##EQU1##

Indoor wideband and narrowband propagation measurements around 60.5 GHz in an empty and furnished room

Abstract: Narrowband and wideband measurements around 60.5 GHz were carried out firstly in an empty room and secondly in the same room with furniture. Using a narrow beam antenna and rotating positioning system at the receiver, results on direction of arrival of waves and wall reflection coefficients have been obtained. Additional results on multi-path propagation derived from wideband measurements have been presented. Eventually, comparisons between different polarisation schemes are presented.