Institut Mines-telecom

Ghaya Rekaya Ben-Othman

Asma Mejri

Mohamed-Achraf Khsiba

Yves Jaouen

El-Mehdi Amhoud

Aymen Askri

Mohammed-Achraf Khsiba

Chao Zhang

A communication system having to an open radio access network architecture, the communication system includes a number (K) of user equipments configured to exchange messages through the communication system, the communication system comprising one or more radio unit and a distributed unit, each radio unit being connected to the distributed unit through a fronthaul link having a given capacity. The communication system comprises a coordination system being configured to coordinate the exchanges between the radio units of the system and the distributed unit, in response to a signal received by the radio units from a user equipment. The coordination system is configured to send a signalling message to each radio unit comprising data stream selection information, each radio unit comprising: a transformation unit configured to apply a transformation operation to the signal vector received by the radio unit, which provides a transformed vector, the transformation operation being defined to reduce the dimension of the received signal vector; a data stream selection unit configured to select a number of data streams corresponding to components of the transformed vector using the data stream selection information comprised in the signalling message, a quantizer configured to apply a quantization operation to the selected data streams, which provides quantized vectors, the radio unit being configured to send the quantized vectors to the distributed unit. The sum of the numbers of data streams selected at the radio units, over all the radio units of the communication system, is higher or equal to the product of the number of user equipments (K) and the number of antennas of a user equipment.

System and method for uplink coordinated transmission in an open radio access network

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:

Methods and devices for sub-block decoding data signals

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

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.

Methods and devices for decoding data signals

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: The decoder being configured to determine at least one estimate of said vector of information symbols from at least one of the lattice points found by the symbol estimation unit ().

Methods and devices for sequential sphere decoding

Embodiments of the invention provide a decoder () 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: The at least one symbol estimation unit is configured to apply at least one iteration of a sequential decoding algorithm, the sequential decoding algorithm comprising iteratively filling a 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 at least a part of the received signal and each node being assigned an initial metric. The symbol estimation unit is further configured to calculate a modified metric for at least one node of the expanded child nodes from the metric associated with the at least one node and from the sub-block weighting coefficient calculated for the sub-vector to which the at least one node belongs, symbol estimation unit being configured to assign the modified metric to the at least one node.

Weighted sequential decoding

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:

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

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 () 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 () 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 () configured to determine an initial metric for each child node of said set of expanded child nodes, wherein the decoder further comprises a modified metric calculation unit () configured to calculate a modified metric for at least one of the expanded child nodes from the metric associated with said expanded child node and a weighting coefficient, said weighting coefficient being a function of the level of said node in the decoding tree, the decoder assigning said modified metric to said at least one of the expanded child nodes.

Parameterized sequential decoding

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

Embodiments of the invention provides a decoder for decoding a signal received through a transmission channel in a communication system, said signal carrying information symbols selected from a given alphabet and being associated with a signal vector, said transmission channel being represented by a channel matrix, wherein said decoder comprises:

Semi-exhaustive recursive block decoding method and device

Embodiments of the invention provide a decoder for decoding a data signal received through a transmission channel in a communication system, said transmission channel being represented by an upper triangular matrix, said signal carrying transmitted symbols, each symbol carrying a set of information bits, wherein said decoder comprises:

Recursive sub-block decoding

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: The decoder being configured to determine at least one estimate of a vector of transmitted information symbols from said at least one estimate of each sub-vector of information symbols.

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Antony, France

Ghaya Rekaya Ben-Othman