Abstract: Disclosed is an apparatus for measuring a bit error rate (BER) in an orthogonal frequency division multiplexing (OFDM) communication system. A transmitter includes a pilot pattern inserter for inserting a first reference pilot pattern in subchannels of input data, and an OFDM modulator for OFDM-modulating the reference pilot pattern-inserted transmission data. A receiver includes a pilot pattern detector for OFDM-demodulating a data symbol received in a frame unit and detecting only a pilot pattern, and a BER operator for comparing the demodulated pilot pattern with a second reference pilot pattern, detecting and accumulating the number of pilot errors, and measuring a bit error rate by dividing the accumulated number of the pilot errors by the number of total received pilot patterns.

Abstract: A process and device for generation of a random signal, and a digital-analog conversion system using such a random signal.

Abstract: The device comprises a traffic summator (4) for summing the number of cells which are present on each incoming highway of the switch during each cell instant and are destined for one and the same outgoing highway (p). A highway emulation group (p) is allocated to each outgoing highway. It is composed of a specified number of counters (Bi) simultaneously loaded with the total number of cells which are destined for the outgoing highway and are presented on the incoming highways of the switch. The respective counts of each counter (Bi) are limited by thresholds (Si) so as to estimate, when the number of cells totalled up in a counter (Bi) exceeds a threshold (Si), the number of cells which may be lost on the corresponding outgoing highway (p).

Abstract: To make optimum use of an available volume exhibiting in particular surfaces of small radius of curvature, with a view to housing electronic circuits therein, a stack (11) of layers of possibly different compositions (circuits, components, insulants, etc.) is made, these layers being parallel to the surface of largest dimension of this volume.

Abstract: A process for real-time reconfiguring of trajectories or airborne vehicles in order to adapt a mission to suit a new situation that has arisen through the occurrence of a disrupting event. The process updates real-time context data modified by the occurrence of the disrupting event and analyzes the new real-time context thus obtained in order to select a predefined reconfiguration method chosen from a set of different predefined methods stored in memory, each of these methods directly translating operational strategies customarily employed by aircrew in a given real-time context so as to determine a new trajectory which best suits the current real-time context.

Abstract: A process and device for measuring the proportion of ATM cells satisfying a criterion. The process includes allocating a first numerical value to the cells passing through a specified point of an ATM network for satisfying criterion and allocating a second numerical value to the cells which do not satisfy the criterion. An exponential mean is then performed of the string of values thus allocated to each cell.

Abstract: A digital holography device, applicable for example to the 3D mapping of objects, is used to determine the complex amplitude of a signal wave coming from an object illuminated by a known illumination wave. For this purpose, the device includes a source for the generation of two mutually coherent waves, the object illumination wave and a reference wave, the two waves having a phase difference &phgr;i(t) that is a function of time. The device also includes a mechanism configured to induce an interference, on a detection device, between the reference wave and the signal wave coming from the object. The detection device enables a temporal sampling of the interference pattern resulting in the acquisition of a number N of interferograms, N being greater than or equal to 2.

Abstract: The device comprises a current/voltage transformer (1) coupled by its primary winding between a matching device (2) of an antenna (3) and the output of an amplifier (4) for the supply or the antenna (3), a first (5a) and a second (5b) baseband digital frequency transposition device respectively coupled to the output of the amplifier (4) and to the secondary winding of the transformer (1), and a computation device (7) to compute the impedance of the antenna (3) from signals given by the first frequency transposition device (5a) and the second frequency transposition device (5b).

Abstract: The present invention relates to a process for translating an ATM cell header for the routing thereof over a transmission highway of a communication network via an ATM switch, consisting in having the switch translate the pair (VPI, VCI) contained in the cell header, the first field VPI identifying a virtual path number and the second field VCI selecting a specified virtual channel within the virtual path.

Abstract: A processing device for air/ground reconnaissance using optronic equipment of high performance. A high speed detection matrix and a particular electronic processing of video signals is used to reconstruct a scan image from elementary images which have a high degree of overlap and are offset due to scan residual. For example, an incident light beam is projected in the direction of a line of sight through an optical system. Video signals are transmitted to a digital circuit to supply luminance values of successive elementary images to two image memories. A correlation processor delivers an offset signal for the current image to an image reconstruction processor which also receives luminance values for the current images. An image patch memory is reconstructed in which the elementary images are realigned.

Abstract: A low-loss surface acoustic wave filter on a quartz substrate with optimized cutting. A range of cutting angles and directions of propagation of the waves on the quartz substrate are defined, making it possible to obtain high coefficients of reflection of the electrodes used in the filter. The range of cutting angles and directions of propagation of the waves are decisive factors for the making of the filter.

Abstract: A method for position determination with the aid of GPS satellites, including reception processing of a GPS satellite signal L2 modulated by an encrypted code Y having a key not available from the GPS satellite, so as to assess a delay of the signal L2 with respect to the signal L1 and to deduce therefrom the magnitude of the ionospheric effect so as to take account thereof and improve the accuracy of the location finding.

Abstract: A landing aid device comprises processing means, which receive aircraft path data, and data regarding the position of at least one runway towards which the aircraft is steering. These processing means comprise calculation means which supply a state signal, comprising at least one condition which is dependent on the path data and on the runway data, this function being chosen so as to express the fact that the path of the aircraft converges towards the runway.

Abstract: A surface acoustic wave filter includes first and second channels, each channel including at least one input transducer and one input transducer. The transfer functions of the first channel and of the second channel are in phase in the passband of the filter and in antiphase in the rejection band of the filter. The filter enables the use of frequency responses for each channel, with wide bands enabling high reduction of the size of the filter while at the same time reducing the rejection band of the total filter. Such a filter may find particular application to mobile telephony.

Abstract: An optical control device for an electronic scanning antenna having at least two controlled radiating elements, and including means for providing first and second mixed light beams, the first light beam polarized according to a first direction and having a first wavelength (&lgr;1), and the second light beam, polarized according to a second direction and having a second wavelength (&lgr;2); at least two optical delay circuits each receiving the first and second mixed light beams and configured to induce complementary delays compared to a determined time value on the first and second beams; chromatic separators each situated at the output of a corresponding one of the delay circuits and configured to separate the light having the first wavelength (&lgr;1) from the light having the second wavelength (&lgr;2); first photodetectors each coupling a corresponding radiating element to a corresponding chromatic separator; second photodetectors each coupling a corresponding chromatic separator to a corresponding first

Abstract: A method for the detection of a target by a radar in the presence of noise, the detection being performed on M antenna rotations, comprises at least: a first step for the estimation of the Doppler frequency ({circumflex over (f)}) of the target; a detection step, the target being detected if an associated variable Z is greater than or equal to a predetermined threshold S, the variable Z being defined according to the following relationship: Z = MAX t ∈ D t , f ∈ D f ⁢ ( ∑

Abstract: The semiconductor device comprises at least one chip arranged on a support. The chip is coated with an electrically insulating and heat-stable material. This electrically insulating and heat-stable material is penetrated by electrical-connection leads connecting sites of the chip to metallized contacts, and leads are substantially perpendicular both to the said sites and to the said metallized contacts.

Abstract: The method consists of the adding of a dither signal of constant amplitude, frequency-modulated by noise, to the signal applied to the input of the converter. An automatic control link is set up between the level of the added interference signal and the signal applied to the input of the converter so that the level of the input signal added to the level of the added interference signal is equal to the level of the full scale signal of the converter. Application to digital communications radio receivers.

Abstract: A device for harmonizing a laser beam path with an observation path for a target includes a laser that generates a laser beam; a first optical element that directs a first part of the laser beam toward the target along the laser beam path while directing a second part of the laser beam toward a conversion device; and a second optical element that directs a converted beam from the conversion device to a sensor that receives the converted beam and an image from the target. The conversion device includes a photoluminescent material that converts the second part of the laser beam into a converted radiation having a wavelength within a spectral band of the sensor, and an optical assembly that focuses the second part of the laser beam into the photoluminescent material and that collects at least a portion of the converted radiation to form the converted beam. The photoluminescent material can include photoluminescent ions such as erbium ions, or a semiconductor material such as indium arsenide.

Abstract: An optical read/write device for an information medium which includes a transparent substrate having an approximately plane face carrying at least one pair of electrodes defining an airgap area whose size corresponds approximately to the size of the information item to be written or to be read. The pair of electrodes constitute a resonator for an incident electromagnetic wave having one component of its electric field parallel to the direction of alignment of the electrodes of the pair of electrodes. An optical source illuminates the electrodes with an optical beam, one component of the electric field of which is parallel to the direction of alignment of the pair of electrodes. Under these conditions, when excited by the beam F1, the electrodes will re-emit a beam which has a field concentration within the airgap. The re-emitted beam makes it possible to read/write information on an information medium placed near the electrodes.