Abstract: The invention relates to a transition device between a printed transmission line on a dielectric substrate and a rectangular waveguide including a front face forming an inlet of the waveguide, a rear face parallel to the front face and forming an outlet of the waveguide, a lower face, an upper face parallel to the lower face, the upper and lower faces extending between the front and rear faces, the waveguide being a block of dielectric material whereof the faces are fully metallized except for the front face and the rear face, the transition device including: a three-dimensional cavity formed in the volume of the waveguide between the inlet of the waveguide, further forming the inlet of the cavity, and the rear face widening, the cavity being at an inlet height of the lower face of the waveguide and ending at a distance from the inlet of the cavity at an outlet height greater than the inlet height; an electrical connection extending from the transmission line along the front face of the waveguide up to the in

Abstract: A method of retrieving a file, the method including: receiving a portion of a content transmitted in accordance with a multicast protocol via a file delivery service, wherein the content includes data fragments forming a file; receiving a file delivery table (FDT) from the file delivery service; reading in the file delivery table location attributes indicating locations of the data fragments in the file; and determining from the location attributes locations of non-corrupted data fragments in the content portion.

Abstract: There is provided a method of generating a space-time block code (STBC) for encoding a digital data sequence comprising a set of independent symbols to be transmitted through a transmission channel in a communication system, the space-time block code being represented by a set of linear dispersion matrices in a linear dispersion representation, each linear dispersion matrix comprising components having complex values, the method comprising, generating at least some of the linear dispersion matrices depending on component-wise conditions related to a set of selected pairs of the linear dispersion matrices, each pair comprising a first linear dispersion matrix and a second linear dispersion matrix, said component-wise conditions comprising a component-wise condition between the components of the first linear dispersion matrix and the components of the second linear dispersion matrix.

Abstract: The invention discloses an antenna arrangement and a method of designing the same, the antenna arrangement being tuned to radiate in a plurality of bands. The antenna arrangement comprises a first conductive element which has a compact linear 2D or 3D form factor. It also comprises leaves attached to the first conductive element, the position, dimension, form factor and orientation of which are defined based on their impact on frequency shifts of the fundamental and harmonic modes, so that the antenna arrangement radiates at a plurality of predefined frequencies. The design method uses maps of hot areas where the sensitivity to the parameters defined for the leaves is maximal. Advantageously, the design method is performed in a manner which uses an orthogonality of the impacts of the parameters of the leaves vis-à-vis the different radiating modes. The antenna arrangement is compact and well adapted to applications to the IoT and consumer communication devices.

Abstract: An encoder architecture for UF-OFDM is provided, in which samples are first processed sub-band wise, and then resorted for sub-carrier-wise processing. The sub-carrier processing may comprise separate processing for the two extremity parts of the base band signal corresponding to the transient state of the UF-OFDM data stream and for a core part of the base band signal corresponding to the non-transient state of the UF-OFDM data stream, and then concatenated to obtain a UF-OFDM data stream. In certain embodiments a first extremity part of the base band signal corresponding to the transient state of the UF-OFDM data stream is calculated directly, and the other extremity part inferred from the core part and the first extremity part. The core and extremity part processors may be implemented with filters adapted to multiply each sample by a respective filter coefficient. Modifying these coefficients can introduce a frequency shift or convert the encoder for OFDM encoding.

Abstract: Power allocation in NOMA systems for example on the basis Proportional Fairness calculations depends on knowledge of user throughput on a specified sub-band, which implies that users have already been allocated to particular sub-bands. Meanwhile, maximum throughput can generally be achieved where there is the greatest possible difference in transmission power for the users on a given sub-band, so that optimal allocation of users to sub-bands requires knowledge of the power available for each user.

Abstract: Embodiments of the invention provides a deterministic scrambler (1) arranged in a multimode optical fiber (130) for scrambling light, the light comprising a set of optical signals propagated in said multimode optical fiber according to a set of propagation modes, each propagation mode being associated with a power value, wherein the scrambler is configured to determine a permutation of said propagation modes depending on the power values associated with said propagation modes, the scrambler being configured to redistribute the optical signals according to said permutation of the propagation modes.

Abstract: Embodiments of the invention provide an optical transmitter configured to transmit a data sequence over at least two spatial propagation modes through an optical transmission channel in a multi-mode optical fiber transmission system, the transmission system being associated with a predefined value of a mode-dependent loss, wherein the optical transmitter comprises: a forward error correcting code encoder (22) configured to encode said data sequence into a codeword vector by applying at least one error correcting code; a modulator (23) configured to determine a set of modulated symbols by applying a modulation scheme to said codeword vector; and a Space-Time encoder (24) configured to determine a codeword matrix by applying a Space-Time code to said set of modulated symbols.

Abstract: A receiver for Filter Bank Multicarrier frequency spread signals such as FBMC, FBMC/OQAM, OFDM, comprises a linear phase rotation module adapted to introduce a linear phase rotation to a received time domain signal, a discrete Fourier transform and a Finite Impulse response digital filter. The coefficients of the digital filter define a shift of the frequency response of the prototype filter of the receiver, and the coefficients of the digital filter are fixed so as to compensate the linear phase rotation introduced by the filter. The frequency shift introduced may be equal to the reciprocal of a power of two of the modulation sub carrier spacing.

Abstract: Embodiments of the invention provide a Space-Time coding device for encoding a digital data sequence according to a predefined space-time coding rate, said data sequence comprising a set of modulated symbols to be transmitted over at least two propagation modes, during a number of time slots, through an optical transmission channel in a single-core multimode optical fiber transmission system, wherein the device comprises: a codebook generator (53) configured to determine a set of codeword matrices defining a space-time code represented by a space dimension and a temporal dimension, each codeword matrix comprising complex values and a number of columns equal to said code temporal dimension, and a number of rows equal to said code space dimension, the codebook generator (53) being further configured to associate a difference codeword matrix and a distance metric to each pair of codeword matrices among said set of codeword matrices, each component of a difference codeword matrix associated with a given pair o

Abstract: Embodiments of the invention provide a decoder for decoding a signal represented by a vector of information symbols received through a transmission channel in a communication system, said the transmission system being represented by a channel state matrix, said information symbols being selected from a given set of values carrying a set of information bits, wherein said decoder comprises: a division unit (202) configured to divide the channel state matrix into a number of sub-blocks of column vectors, in accordance with a division of said vector of information symbols into a number of sub-vectors; a permutation unit (203) configured to determine a set of permuted channel state matrices by permuting said sub-blocks of column vectors, the permutation unit (203) being further configured to select at least one permuted channel state matrix among said set of permuted channel state matrices according to a selection criterion; a sub-block decoding unit (207) configured to determine a transformed signal from said

Abstract: A method of selecting, for at least one service of an information system and depending service(s), at least one countermeasure to be implemented against at least one cyber attack, the method includes: identifying elements of the service exposed to the cyber attack(s), calculating a risk mitigation level of each countermeasure with respect to the cyber attack(s), ranking the countermeasure(s) on the basis of a parameter which is at least a function of the risk mitigation level, simulating the impact of the countermeasure(s) on the service and the depending service(s), the countermeasure to be implemented being selected at least as a function of result of the simulation.

Abstract: The invention relates to a reflecting cell including at least two substrates covered by an electrode and facing each other, the substrates delimiting between them a volume which separates them and which is filled with a cholesteric liquid crystal-type material, both electrodes being intended to be connected to a voltage source. This cell includes at least one half-wave plate arranged between both substrates and dividing the volume into two compartments, each enclosing a part of a same cholesteric liquid crystal.

Abstract: A method of designing a digital filter for example for use in an FBMC/OQAM telecommunications system, with a target overlapping factor and meeting a specified signal to interference ratio is described, whereby a candidate filter design defined by an impulse response, satisfying the Nyquist criterion and having an overlapping factor higher than the target is selected, and the time and frequency coefficients of its impulse response inverted to define a new filter design; and truncating the impulse response defining said new filter design to the minimum number of coefficients achieving said specified signal to interference ratio.

Abstract: A reflecting cell including at least two substrates each covered by an electrode and facing each other, the substrates delimitating between them a volume which separates them and which is filled with a bistable liquid crystal-type material with a threshold field, for example a cholesteric liquid crystal, both electrodes being intended to be connected to a voltage source. This cell is characterized in that at least one of the electrodes is formed by associating a pattern, which does not entirely cover the surface of the substrate considered, and a conducting layer which covers the surface of the substrate considered, the conductivity of the material of the layer being lower than that of the material of the pattern.

Abstract: Embodiments of the invention provide a decoder for decoding a signal received through a transmission channel in a communication system, said signal comprising a vector of information symbols, said transmission channel being represented by a channel matrix, wherein the decoder comprises: an initial radius determination unit (307) configured to determine an initial radius; a symbol estimation unit (309) configured to iteratively determine a current radius to search a lattice point inside a current spherical region defined by said current radius, said current radius being initially set to said initial radius, said symbol estimation unit (309) being configured, for each lattice point found in said current spherical region, to store said lattice point in association with a metric, said symbol estimation unit (309) being further configured to update said current radius using a linear function, said linear function having a slope parameter strictly inferior to one, The decoder being configured to determine at

Abstract: Embodiments of the invention provide a decoder for decoding a signal received through a transmission channel in a communication system, said signal comprising a vector of information symbols, said transmission channel being represented by a channel matrix comprising column vectors, said information symbols carrying information bits, wherein the decoder comprises: a transformation unit (401) configured to determine a set of auxiliary channel matrices, each auxiliary channel matrix being determined by performing a linear combination of at least one of the column vectors of said channel matrix; a decomposition unit (407) configured to determine a decomposition of each auxiliary channel matrix into an upper triangular matrix and an orthogonal matrix; a matrix selection unit (409) configured to select at least one auxiliary channel matrix among said set of auxiliary channel matrices depending on a selection criterion related to the components of said upper triangular matrices.

Abstract: Methods, systems, and computer program products for decoding a received data signal in a communication system by iteratively constructing a decoding tree, each node of said decoding tree corresponding to a component of a symbol of said data signal, and being associated with a metric, the construction of the decoding tree implementing at least one iteration of the following steps, for a current node of the tree stored in the top of a stack: generating (102) a reference child node of said current node from said vector representing the received data signal, from the reference child node, generating (106) a first neighbor child node by subtracting a positive integer parameter from the value of the reference node, and a second neighbor child node by adding said positive integer parameter to the value of the reference child node; storing (108) in said stack three child nodes deriving from the reference child node and from said first and second neighbor child nodes, each child node being stored in the stack in as

Abstract: The invention relates to a mode selection method for a system for MIMO transmission on an optical fiber of multimode type. It comprises a step of measuring the transfer matrix of the transmission channel made up of a set of modes of the optical fiber (110), a step of transforming (120) the transfer matrix into a block diagonal matrix, each block being associated with a mode subset, a step of determining (130) the gain and/or the transmission capacity for each of the mode subsets, and a selection (140) of the mode subset corresponding to the highest gain and/or capacity, the MIMO transmission system then using only the modes of the subset thus selected to transmit on the optical fiber. The invention relates also to a core selection method for a system for MIMO transmission on optical fiber of multicore type.

Abstract: A method for detecting if an online review written by a user on a website of a telecommunications network is a spam, using at least one previously-labeled review, a review dataset comprising at least one review to be analyzed, and a spam feature list listing different features of spam reviews, method wherein: a) a weight is computed for each spam feature of the spam feature list, corresponding to the importance of the spam feature in the detection of spam reviews, and based at least on the features of said at least one previously-labeled review, and b) a probability of being a spam for a review under analysis in the review dataset is computed by using at least the weights of the spam features computed at step a) and a comparison between the features of said review under analysis and the ones of at least one review previously-labeled as spam.