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 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: a sub-block division unit (301) 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; a candidate set estimation unit (305) for recursively determining candidate estimates of sub-blocks of the transmitted signal corresponding to said sub-vectors, each estimate of a given sub-block being determined from at least one candidate estimate of the previously processed sub-blocks, wherein said candidate set estimation unit is configured to determine a set of candidate estimates for at least one sub-block of the transmitted signal by applying at least one iteration of a decodi

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: 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.

Abstract: 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.

Abstract: The present invention concerns a method for relaying symbols transferred by a source to a destination in a wireless cellular telecommunication network, the symbols being relayed by a relay, the relay receiving symbols, the symbols being representative of coded bits derived from information bits. The relay: receives symbols, successfully decodes the information bits from the symbols, determines a spectral efficiency to be used for transferring symbols from the number of coded bits transferred by the source prior the successful decoding of information bits, transfers symbols using a modulation that corresponds to the determined spectral efficiency.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The present invention concerns a method for determining if an information word transferred by a source has to be relayed by a telecommunication device. The signals transferred by the source are composed of complex symbols obtained from the information word. The telecommunication device: receives at least one signal composed of complex symbols transferred by at least the source, successfully decodes the information word from the at least one received signal composed of complex symbols, checks if the successful decoding is performed prior to an expected successful decoding time of the information word, the expected successful decoding time being obtained from prior successful decoding of other information words, and if the successful decoding is performed prior to the expected successful decoding time of the information word: obtains at least one signal composed of complex symbols obtained from the information word, transfers the at least one obtained signal.

Abstract: A method of decoding a data signal includes progressively constructing a decoding tree, implementing at least two iterations of the following steps: selecting at least one child node of a current node belonging to a selection interval; storing the child nodes in a first stack; deleting the current node from the first stack; selecting a new current node from the first stack; and if the new current node is a leaf node, storing the path between the root node and the leaf node, in the second stack, and deleting the leaf node from the first stack; otherwise, return to the step of selecting a child node for the new current node. Moreover, the method assigns a probability of likelihood to the bits of at least one symbol of the data signal, taking account of the paths stored in the second stack, and determines a probabilistic estimation of the signal.

Abstract: A method is provided for decoding a signal received by a receiver including at least one reception antenna. The method includes: selecting, among at least two techniques available in the receiver, a decoding technique representative of a space/time encoding implemented upon transmission; and decoding the signal using the selected decoding technique. The selecting step takes into account at least one selection criterion.

Abstract: The present invention concerns a method for relaying symbols transferred by a source to a destination in a wireless cellular telecommunication network, the symbols being relayed by a relay, the relay receiving symbols. The relay: receives symbols, successfully decodes the symbols, generates symbols that have been previously transferred by the source, generates symbols that have not previously been transferred by the source, combines the generated symbols into combined symbols, transfers the combined symbols to the destination.

Abstract: 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.

Abstract: The present invention concerns a method for determining if an information word transferred by a source has to be relayed by a telecommunication device. The signals transferred by the source are composed of complex symbols obtained from the information word. The telecommunication device: receives at least one signal composed of complex symbols transferred by at least the source, successfully decodes the information word from the at least one received signal composed of complex symbols, checks if the successful decoding is performed prior to an expected successful decoding time of the information word, the expected successful decoding time being obtained from prior successful decoding of other information words, and if the successful decoding is performed prior to the expected successful decoding time of the information word: obtains at least one signal composed of complex symbols obtained from the information word, transfers the at least one obtained signal.

Abstract: A method of decoding a data signal includes progressively constructing a decoding tree, implementing at least two iterations of the following steps: selecting at least one child node of a current node belonging to a selection interval; storing the child nodes in a first stack; deleting the current node from the first stack; selecting a new current node from the first stack; and if the new current node is a leaf node, storing the path between the root node and the leaf node, in the second stack, and deleting the leaf node from the first stack; otherwise, return to the step of selecting a child node for the new current node. Moreover, the method assigns a probability of likelihood to the bits of at least one symbol of the data signal, taking account of the paths stored in the second stack, and determines a probabilistic estimation of the signal.

Abstract: A method is provided for decoding a signal received by a receiver including at least one reception antenna. The method includes: selecting, among at least two techniques available in the receiver, a decoding technique representative of a space/time encoding implemented upon transmission; and decoding the signal using the selected decoding technique. The selecting step takes into account at least one selection criterion.

Abstract: The present invention concerns a method for relaying symbols transferred by a source to a destination in a wireless cellular telecommunication network, the symbols being relayed by a relay, the relay receiving symbols, the symbols being representative of coded bits derived from information bits. The relay: receives symbols, successfully decodes the information bits from the symbols, determines a spectral efficiency to be used for transferring symbols from the number of coded bits transferred by the source prior the successful decoding of information bits, transfers symbols using a modulation that corresponds to the determined spectral efficiency.

Abstract: The present invention concerns a method for relaying symbols transferred by a source to a destination in a wireless cellular telecommunication network, the symbols being relayed by a relay, the relay receiving symbols. The relay: receives symbols, successfully decodes the symbols, generates symbols that have been previously transferred by the source, generates symbols that have not previously been transferred by the source, combines the generated symbols into combined symbols, transfers the combined symbols to the destination.