Abstract: The various embodiments provide an optical transmission system comprising an optical transmitter configured to transmit data over an optical fiber transmission channel made of a multi-core fiber, optical signals carrying the data propagate along the multi-core fiber according to two or more cores, the multi-core fiber being associated with fiber parameters and misalignment losses values, wherein the optical transmission system comprises a system administration device configured to determine a core dependent loss value depending on the fiber parameters and misalignment losses values.

Abstract: Embodiments provide an optical transmission system comprising an optical transmitter configured to transmit data over an optical fiber transmission channel comprising a multi-core fiber, the data being carried by one or more optical signals propagating along the multi-core fiber according to a plurality of cores, each core among the plurality of cores being associated with one or more core parameters, wherein the optical transmission system comprises a core selection device configured to select a set of transmit cores among the plurality of cores according to a transmit core selection criterion, the transmit core selection criterion being related to the one or more core parameters, the optical transmitter being configured to transmit the data over the set of transmit cores.

Abstract: The various embodiments provide an optical transmission system comprising an optical transmitter configured to transmit data over an optical fiber transmission channel comprising a multi-core fiber, the data being carried by optical signals, the optical signals propagating along the multi-core fiber according to two or more cores, the multi-core fiber being associated with fiber parameters and misalignment losses values, at least one scrambling device being arranged in the optical fiber transmission channel for scrambling the two or more cores according to a scrambling function, wherein the optical fiber transmission channel comprises a system configuration device configured to determine a core dependent loss value depending on the fiber parameters, at least one misalignment loss, a number of the at least one scrambling device, and the scrambling function.

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: There is provided a decoder for decoding a data signal received through a transmission channel in a communication system, the decoder (310) comprising a symbol estimation unit (311) configured to determine estimated symbols representative of the transmitted symbols carried by the received signal, the estimated symbols being determined from nodes of a decoding tree based on a weight metric associated with each of the node. The decoder further comprises a termination alarm monitoring unit (312) for monitoring a termination alarm depending on the current decoding computation complexity, the termination alarm being associated with a metric parameter, the symbol estimation unit being configured to reduce the weight metric of each node of the decoding tree by a quantity corresponding to a function of the metric parameter associated with the termination alarm, in response to the triggering of the termination alarm.

Abstract: A method, device, and a computer program are provided to decode a signal received through a transmission channel in a communication system, the received signal being represented by a signal vector.

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 an upper triangular matrix, wherein the decoder comprises: a processing unit (309) configured to determine a set of division parameters depending on at least one division metric derived from components of said upper triangular matrix; a decoding unit (311) configured to divide said upper triangular matrix into two or more sub-matrices using said set of division parameters in accordance with a division of said vector of information symbols into two or more sub-vectors, and to determine at least one estimate of each sub-vector of information symbols by applying a symbol estimation algorithm, wherein the decoder is configured to determine at least one estimate of said vector of information symbols from the estimates of said sub-vectors of information symbols.

Abstract: There is provided a decoder (310) for sequentially decoding a data signal received through a transmission channel in a communication system, the received data signal carrying transmitted symbols, the decoder comprising a symbol estimation unit (311) configured to determine estimated symbols representative of the transmitted symbols carried by the received signal from information stored in a stack, the stack being filled by iteratively expanding child nodes of a selected node of a decoding tree comprising a plurality of nodes, each node of the decoding tree corresponding to a candidate component of a symbol of the received data signal and each node being associated with a predetermined metric, the stack being filled at each iteration with at least some of the expanded child nodes and being ordered by increasing values of the metrics associated with the nodes, the selected node for each iteration corresponding to the node having the lowest metric in the stack.

Abstract: The invention relates to a system and a method for transmission over optical fiber (130) with mode or core scrambling. The system comprises a spatio-temporal encoder (110) and a plurality of modulators (1251, . . . , 125n) associated, respectively, with separate propagation modes or cores of said fiber, each modulator modulating a laser beam. Said fiber comprises a plurality of slices (1301, . . . , 130L), an amplifier (140l) being provided between any two consecutive slices of the optical fiber. A mode scrambler (150l) is associated with each amplifier in order to perform a permutation of said modes between at least two consecutive slices.

Abstract: A decoder or a decoding method for decoding a data signal is provided by iteratively constructing a decoding tree comprising nodes, each representing a component of a symbol of a data signal, each iteration comprising, for a current node of the tree stored in the top of the stack; generating a reference child node of the current node from the data signal; from the reference child node, generating a first and second neighbor child nodes by subtracting/adding a positive integer parameter from/to the value of the reference node; storing in the stack three child nodes derived from the reference, first and second neighbor child nodes, the nodes stored in the stack being ordered by increasing values of a node metric; removing the current node stack; selecting the top node of the stack as the new current node. The data signal is estimated from the stack node information.

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: The invention relates to a MAP decoding method of a signal received through a noisy channel, the signal being composed of symbols in an alphabet having a non-uniform probability distribution, the symbols being represented by points in a lattice (?). The probability distribution of symbols is modeled using a Gaussian distribution. An augmented lattice (?exp) is formed from the lattice (?) and the ratio (?) between variance of the noise and variance of the Gaussian distribution of symbols. Therefore, the disclosed MAP decoding method consists essentially of decoding using an ML criterion searching the point in the augmented lattice closest to the point representative of the received signal (yexp).

Abstract: An exemplary decoder is provided for decoding a signal received through a transmission channel in a communication system. The exemplary decoder comprises a transformation unit 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 the channel matrix; a decomposition unit configured to determine a decomposition of each auxiliary channel matrix into an upper triangular matrix and an orthogonal matrix; a matrix selection unit configured to select at least one auxiliary channel matrix among the set of auxiliary channel matrices depending on a selection criterion related to the components of the upper triangular matrices. The decoder determines at least one estimate of vector of information symbols from an auxiliary signal and from the upper triangular matrix corresponding to a selected auxiliary channel matrix by applying a decoding algorithm.

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 (10) for decoding a signal received through a transmission channel in a communication system, the signal carrying information symbols selected from a given set of values and being associated with a signal vector, the transmission channel being represented by a channel matrix. The decoder comprises: a sub-block division unit (12) configured to divide the received signal vector into a set of sub-vectors in correspondence with a division of a matrix related to said channel matrix; at least one weighting coefficient calculation unit (14) configured to calculate a sub-block weighting coefficient for each sub-vector, at least one symbol estimation unit (11) for recursively determining estimated symbols representative of the transmitted symbols carried by the data signal from information stored in a stack.

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, wherein the decoder comprises: a processing unit (307) configured to determine at least one candidate set of division parameters and to perform a division of said vector of information symbols into a set of sub-vectors in association with each candidate set of division parameters, each pair of sub-vectors being associated with a division metric; a selection unit (309) configured to select one of said candidate sets of division parameters according to a selection criterion depending on said division metric; and a decoding unit (311) configured to determine at least one estimate of each sub-vector associated with said selected set of division parameters by applying a symbol estimation algorithm, wherein the decoder is configured to determine at least one estimate of the vector of information symbols from said at least

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: There is provided a decoder for sequentially decoding a data signal received through a transmission channel in a communication system, said data signal carrying transmitted symbols, said decoder comprising a symbol estimation unit (301) configured to determine estimated symbols representative of the transmitted symbols carried by the received signal from information stored in a stack, said symbol estimation unit (301) being configured to iteratively fill the stack by expanding child nodes of a selected node of a decoding tree comprising a plurality of nodes, each node of the decoding tree corresponding to a candidate component of a symbol of said data signal and each node being assigned a metric, the stack being filled at each iteration with a set of expanded child nodes and being ordered by increasing values of the metrics assigned to the nodes, the selected node for each iteration corresponding to the node being assigned the lowest metric in the stack, the decoder comprising a metric determination unit (302

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: 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.