Institut Mines-telecom

France Telecom

Orange

Mimopt Technology

Ghaya Rekaya

Akram Abouseif

Yves Jaouen

Aymen Askri

Ahmed Saadani

Michel Nahas

Charlotte Hucher

A precoder for precoding a vector of information symbols to be sent to a plurality of users, the precoder includes a user ordering and grouping unit configured to group the plurality of users depending on one or more quality of service indicators and on modulation and coding parameters associated with the plurality of users, the user ordering and grouping unit being configured to divide a predefined upper triangular precoding matrix into a plurality of sub-matrices and to divide the vector of information symbols into a plurality of sub-vectors, each sub-vector comprising information symbols to be sent to a group of users, the sub-vectors being arranged according to an arbitrary order of the one or more quality of service indicators; a precoding unit configured to determine a perturbation vector according to the minimization of a transmit power metric, the perturbation vector comprising a plurality of perturbation sub-vectors, each perturbation sub-vector corresponding to a sub-vector of information symbols, the precoding unit being configured to determine an estimate of each perturbation sub-vector by applying a recursive search algorithm.

Devices and methods for recursive block precoding

A precoder for precoding a vector of information symbols is provided. The precoder includes a radius determination unit configured to determine a search sphere radius, the determination of the search sphere radius comprising applying a machine learning algorithm to input data dependent on the vector of information symbols and on a predefined precoding matrix; a sphere encoding unit configured to determine a perturbation vector from lattice points found inside a spherical region by applying a sphere search-based sequential algorithm, the spherical region having as a radius the search sphere radius, and a precoding unit configured to precode the vector of information symbols using the perturbation vector and a precoding matrix.

Devices and methods for machine learning assisted precoding

An optical transmitter for transmitting a vector of information symbols over an optical fiber transmission channel made of a multi-core fiber, optical signals carrying the vector of information symbols propagating along the multi-core fiber according to two or more cores, wherein the optical transmitter includes a precoder configured to determine a precoding matrix depending on one or more fiber parameters associated with the multi-core fiber and to precode the vector of information symbols by multiplying the vector of information symbols by the precoding matrix.

Methods and devices for multi-core fiber data transmission using data precoding

A decoder for decoding a signal received through a transmission channel represented by a channel matrix using a search sphere radius. The decoder comprises a radius determination device for determining a search sphere radius from a preliminary radius. The radius determination device is configured to: i. apply a machine learning algorithm to input data derived from the received signal, the channel matrix and a current radius, the current radius being initially set to the preliminary radius, which provides a current predicted number of lattice points associated with the current radius; ii. compare the current predicted number of lattice points to a given threshold; iii. update the current radius if the current predicted number of lattice points is strictly higher than the given threshold, the current radius being updated by applying a linear function to the current radius; Steps i to iii are iterated until a termination condition is satisfied, the termination condition being related to the current predicted number, the radius determination device being configured to set the search sphere radius to the current radius in response to the termination condition being satisfied.

Devices and methods for machine learning assisted sphere decoding

A decoder for determining an estimate of a vector of information symbols carried by optical signals propagating along a multi-core fiber in an optical fiber transmission channel according to two or more cores is provided. The decoder is implemented in an optical receiver. The optical signals are encoded using a space-time coding scheme and/or scrambled by at least one scrambling device arranged in the optical fiber transmission channel according to a predefined scrambling function. The decoder comprises a processing unit configured to adaptively: determine, in response to a temporal condition, one or more channel quality indicators from the optical signals; determine a decoding algorithm according to a target quality of service metric and on the one or more channel quality indicators; update the predefined scrambling function and/or the space-time coding scheme depending on the target quality of service metric and on the one or more channel quality indicators. The decoder further comprises a symbol estimation unit configured to determine an estimate of a vector of information symbols by applying the decoding algorithm to the optical signals.

Devices and methods for adaptive decoding and core scrambling in multi-core fiber transmission systems

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, each core being associated with one or more core parameters, wherein the optical transmission system comprises: a scrambling configuration device configured to determine a scrambling function depending on one or more of the core parameters associated with the two or more cores, and at least one scrambling device arranged in the optical fiber transmission channel for scrambling the two or more cores, each of the at least one scrambling device being configured to determine permuted cores by applying the scrambling function to the two or more cores and to redistribute the optical signals according to the permuted cores.

Optical transmission system and method for core scrambling for multicore optical fibers

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.

Methods and devices for the determination of core dependent loss in multi-core fiber transmission systems

A decoder for determining an estimate of a vector of information symbols carried by a signal received through a transmission channel represented by a channel matrix is provided. The decoder includes a block division unit configured to divide the vector of information symbols into two or more sub-vectors, each sub-vector being associated with a block level; two or more processors configured to determine, in parallel, candidate sub-vectors and to store the candidate sub-vectors in a first stack. Each processor is configured to determine at least a candidate sub-vector by applying a symbol estimation algorithm and to store each candidate sub-vector with a decoding metric and the block level associated with the candidate sub-vector. The decoding metric is lower than or equal to a decoding metric threshold. A processor among the two or more processors is configured to determine at least a candidate vector from candidate sub-vectors stored in the first stack, the candidate vector being associated with a cumulated decoding metric and to update the decoding metric threshold from the cumulated decoding metric.

Devices and methods for parallelized recursive block decoding

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.

Methods and devices for the determination of core dependent loss in multi-core fiber transmission systems using core scrambling

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.

Optical transmission system and method for core selection in multi-core fibers

A method and apparatus are provided for transmitting frames of N&#x3e;2 symbols for use in a distributed system having at least two transmitter nodes. The method includes circularly permutating a frame of N symbols; multiplying m first permutated symbols by a phase coefficient &#x3c6;&#x2260;1, for 0&#x3c;m&#x2266;[N/2]+1; and one of the nodes transmitting the frame including the multiplied permutated symbols and another of the nodes transmitting the frame of N symbols.

Growing community of inventors

Antony, France

Ghaya Rekaya