Institut Mines-telecom

Institut Telecom/telecom Paristech

Yves Jaouen

Ghaya Rekaya-Ben Othman

Ghaya Rekaya

Akram Abouseif

Ghaya Rekaya Ben-Othman

Sami Mumtaz

El-Mehdi Amhoud

Elie Awwad

Bruno Thedrez

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

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

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

Method and system of optical fibre with switching of modes and/or cores

Embodiments of the invention provides a deterministic scrambler () arranged in a multimode optical fiber () 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.

Scrambler for a multimode optical fiber and optical transmission system using such scrambler systems

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:

Space-time coding methods and devices for optical MIMO systems

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:

Joint space-time and FEC coding in multi-mode fiber optical transmission systems

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 (), a step of transforming () the transfer matrix into a block diagonal matrix, each block being associated with a mode subset, a step of determining () the gain and/or the transmission capacity for each of the mode subsets, and a selection () 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.

Method for selecting modes for transmission over multimode or multicore optical fibres

A transmitter for an optical telecommunication system on a weakly multimode fiber is disclosed. One aspect is a transmitter including an encoder transforming each block of symbols to be transmitted into a code matrix, each element of the matrix being relative to a time of use and to a propagation mode of the weakly multimode fiber. The transmitter can include a plurality of modulators respectively associated with the different propagation modes, each modulator modulating a laser beam during a time of use. Each modulator can modulate a laser beam by use of an element of the corresponding matrix, the elements of the matrix of the code being subjected beforehand to an OFDM modulation upstream of said modulators. Each of the modulated beams can be input into the weakly multimode fiber to propagate therein according to a separate mode.

System for transmission over a multi-mode and/or multi-core optical fiber

A transmitter and a receiver for an optical telecommunication system of the WDM type are disclosed. In one aspect, the transmitter uses a chromato-temporal encoder which, with each block of symbols to be transmitted, associates a code matrix, where each element of the matrix corresponds to a wavelength and a use of the channel. The transmitter includes multiple modulators, where each modulator modulates a laser beam at a wavelength during a use of the channel by an element corresponding to the code matrix. The beams modulated in this manner are multiplexed in an optical fiber. Another embodiment using both a wavelength and a polarization encoding is also proposed.

Method and system for WDM transmission with chromato-temporal encoding

A method and apparatus are provided for modulating a binary source sequence including of a plurality of source words to generate modulated symbols. The method implements error-correction encoding of the plurality of source words, implementing one or more encoding modules, each implementing a separate error-correction code to generate a plurality of code words, the source words being encoded in series. The code words are interlaced to generate an interlaced sequence. The interlaced sequence is differentially modulated to generate modulated symbols. Each code word is broken down into at least one group with a number of bits equal to the base-2 logarithm of a number of states of a modulation implemented by the step of differentially modulating. The interlacing step distributes the groups such that two adjacent groups in the interlaced sequence belong to separate code words.

Modulation method and device implementing a differential modulation, corresponding demodulation method and device, signal and computer software products

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Paris, France

Yves Jaouen