Abstract: A method of transmitting, by a first device, pilot symbols to allow a second device to estimate a transmission channel between the first and second devices. The first device has a first antenna that is active in transmission and a second antenna that is passive in transmission. The method includes: transmitting, by the first active antenna, a signal conveying pilot symbols associated with the first active antenna, and during which the second passive antenna is set to a transparency impedance to obtain a level of signal backscattered by the second passive antenna less than a first threshold; and transmitting by the first active antenna a signal conveying pilot symbols associated with the second passive antenna, and during which the second passive antenna is set to a scattering impedance to obtain a level of signal backscattered by the second passive antenna greater than a second threshold greater than the first threshold.

Abstract: A communications method executed by a node of a telecommunications network, the method includes: a training step including determining a “transmission” filter as a function of a received training signal; and a data transmission step of transmitting data to a target node of the network while using the transmission filter as determined during the training step.

Abstract: An iterative precoding method for a TDD data transmission system includes a transmitter provided with N transmit antenna(s) (N?1), and a receiver provided with M receive antennas (M?2). A series of precoders Ln (n?0) is defined. Each iteration includes: the transmitter takes account of a predetermined value n=n0 if it is the first iteration, or else a value of n obtained during the preceding iteration; the transmitter sends a triplet of pilot signals precoded with the precoders Ln, Ln+1, and Ln+2 to the receiver; the receiver estimates the triplet (Tn, Tn+1, Tn+2) of total data rates that can be achieved corresponding respectively to (Ln, Ln+1, Ln+2), and deduces therefrom the value of a control command p; the receiver sends a signaling message specifying the value of the control command p; and on receiving the signaling message, the transmitter updates the value of n, by replacing it with the value (n+p).

Abstract: A method is provided for transmitting data between a transmitter having M>=1 transmit antenna(s), and one or more receivers having a total of N>=2 receive antennas. In the method, the data are transmitted using OFDM/OQAM modulation having L>=1 subcarriers. The transmitted data are pre-encoded using a pre-encoding matrix, the size of which is M s N and which is dependent on a zero-forcing matrix and on a spatial multiplexing matrix.

Abstract: A method establishing a quality indicator of a radio transmission channel in a first cell of a cellular network using a plurality of orthogonal frequency-division multiplexed subcarriers for transmitting data. A first transmitter located in the first cell transmits a reference control signal including a total-load control signal modulating one or more of the orthogonal subcarriers, during one or more first symbol times dedicated to transmission of symbols other than data symbols, and a useful-load control signal modulating one or more orthogonal subcarriers during at least one second symbol time dedicated to transmission of data symbols. A transmitter located in an adjacent cell transmits an interfering control signal modulating, during the first symbol time(s). The quality indicator is determined according to a measured quality indicator of the channel under the useful load and a measured quality indicator of the channel under the total load.

Abstract: Disclosed is a transmission method of transmitting at least one multicarrier signal made up of OFDM-OQAM symbols to a receive antenna of a receiver device, the transmission method being for use by a transmitter device having at least one transmit antenna. In one embodiment, the method comprises, for each transmit antenna of the transmitter device, filtering OFDM-OQAM symbols associated with the transmit antenna using a time-reversal prefilter defined from an estimate of the transmission channel between the transmit antenna and the receive antenna and transmitting the filtered OFDM-OQAM symbols via the transmit antenna over the transmission channel.

Abstract: The invention relates to a multiantenna radio communications method wherein frequency subbands Bsk, for k=1, . . . , P, are allocated respectively to P user antennas s1, . . . , sp belonging to one or more users, from within a total frequency bandwidth BT, and wherein at least one of the user antennas communicates with the base station over its respective frequency subband Bsk by means of a signal that has been filtered by time reversal. According to the invention, for at least one pair of user antennas Si and Sj, where and i,j=1, . . . , P and i?j, the respective frequency subbands Bsi and Bsj overlap by ?Bsi,sj, said overlap ?Bsi,sj being a predetermined function of the correlation between the respective propagation channels of these two user antennas with said base station.

Abstract: A method of transmitting data between a transmitter furnished with M>=1 transmission antenna(s) and a receiver furnished with N>=2 reception antennas, in which said data are coded using an OFDM/OQAM modulation having L>=1 subcarriers. The method combines a specific coding/decoding with a precoding by Time Reversal, which can be used in high speed radio communications.

Abstract: Disclosed is a method for transmitting from a transmitter device having M transmit antennas to a receiver device having N+C receive antennas, where M, N, and C are integers greater than or equal to 1. In one embodiment, the method comprises a process of spatial frequency multiplexing a block of N data symbols D1, D2, . . . , DN resulting in a block of N payload spatial symbols Su,1, Su,2, . . . , Su,N, using an inverse discrete Fourier transform (IDFT), a process of adding C redundancy spatial symbols to the block of N payload spatial symbols, resulting in a block of N+C spatial symbols S1, S2, . . . , SN+C, and a process of precoding the block of N+C spatial symbols S1, S2, . . . , SN+C with the help of a focusing matrix of dimensions M×(N+C), delivering M precoded spatial symbols X1, X2, . . . , XM, each precoded spatial symbol being transmitted over a distinct transmit antenna.

Abstract: A method of transmitting data between a transmitter furnished with M>=1 transmission antenna(s) and a receiver furnished with N>=2 reception antennas, in which said data are coded using an OFDM/OQAM modulation having L>=1 subcarriers. The method combines a specific coding/decoding with a precoding by Time Reversal, which can be used in high speed radio communications.

Abstract: A method is provided for transmitting data between a transmitter having M>=1 transmit antenna(s), and one or more receivers having a total of N>=2 receive antennas. In the method, the data are transmitted using OFDM/OQAM modulation having L>=1 subcarriers. The transmitted data are pre-encoded using a pre-encoding matrix, the size of which is M s N and which is dependent on a zero-forcing matrix and on a spatial multiplexing matrix.

Abstract: A method of guidance by radio focusing includes a “visitor” entity heading towards a radio source of number k=1 (or k=klast) by observing intensity of the radio source of number k=1 (or k=klast) as measured by an “Evisitor” communicating device carried by the visitor, until the visitor reaches the source of number k=1 (or k=klast). The visitor heads in succession for k=1, 2, . . . , klast-1 (or in reverse) from a radio source of number k towards a radio source of number (k+1) (or (k?1)) by observing intensity of the source (k+1) (or (k?1)), until the visitor reaches the source (k+1) (or (k?1)). Each radio source is a virtual radio source as produced by a respective signal k or by superposing a plurality of respective signals k. Each signal is transmitted by a respective communicating device ER.

Abstract: Disclosed is a method for transmitting from a transmitter device having M transmit antennas to a receiver device having N+C receive antennas, where M, N, and C are integers greater than or equal to 1. In one embodiment, the method comprises a process of spatial frequency multiplexing a block of N data symbols D1, D2, . . . , DN resulting in a block of N payload spatial symbols Su,1, Su,2, . . . , Su,N, using an inverse discrete Fourier transform (IDFT), a process of adding C redundancy spatial symbols to the block of N payload spatial symbols, resulting in a block of N+C spatial symbols S1, S2, . . . , SN+C, and a process of precoding the block of N+C spatial symbols S1, S2, . . . , SN+C with the help of a focusing matrix of dimensions M×(N+C), delivering M precoded spatial symbols X1, X2, . . . , XM, each precoded spatial symbol being transmitted over a distinct transmit antenna.

Abstract: A method and apparatus are provided for transmitting a source signal including a plurality of binary sequences to NR receiving antennas, where NR is no lower than 2. The method implements, for at least one first binary sequence of the source signal, pre-filtering for focusing a signal to be transmitted on at least one of the reception antennas, referred to as the target antenna. The target antenna and the associated focus pre-filtering step are selected according to a value of the first binary sequence intended for being considered as received. The method also includes transmitting the pre-filtered signal.

Abstract: A method establishing a quality indicator of a radio transmission channel in a first cell of a cellular network using a plurality of orthogonal frequency-division multiplexed subcarriers for transmitting data. A first transmitter located in the first cell transmits a reference control signal including a total-load control signal modulating one or more of the orthogonal subcarriers, during one or more first symbol times dedicated to transmission of symbols other than data symbols, and a useful-load control signal modulating one or more orthogonal subcarriers during at least one second symbol time dedicated to transmission of data symbols. A transmitter located in an adjacent cell transmits an interfering control signal modulating, during the first symbol time(s). The quality indicator is determined according to a measured quality indicator of the channel under the useful load and a measured quality indicator of the channel under the total load.

Abstract: An iterative precoding method for a TDD data transmission system includes a transmitter provided with N transmit antenna(s) (N?1), and a receiver provided with M receive antennas (M?2). A series of precoders Ln (n?0) is defined. Each iteration includes: the transmitter takes account of a predetermined value n=n0 if it is the first iteration, or else a value of n obtained during the preceding iteration; the transmitter sends a triplet of pilot signals precoded with the precoders Ln, Ln+1, and Ln+2 to the receiver; the receiver estimates the triplet (Tn, Tn+1, Tn+2) of total data rates that can be achieved corresponding respectively to (Ln, Ln+1, Ln+2), and deduces therefrom the value of a control command p; the receiver sends a signaling message specifying the value of the control command p; and on receiving the signaling message, the transmitter updates the value of n, by replacing it with the value (n+p).

Abstract: Disclosed is a transmission method of transmitting at least one multicarrier signal made up of OFDM-OQAM symbols to a receive antenna of a receiver device, the transmission method being for use by a transmitter device having at least one transmit antenna. In one embodiment, the method comprises, for each transmit antenna of the transmitter device, filtering OFDM-OQAM symbols associated with the transmit antenna using a time-reversal prefilter defined from an estimate of the transmission channel between the transmit antenna and the receive antenna and transmitting the filtered OFDM-OQAM symbols via the transmit antenna over the transmission channel.

Abstract: A method of pre-equalizing a data signal transmitted in frequency division duplex includes receiving via an originating reference antenna a first pilot sequence transmitted by a destination antenna through a first channel, and estimating a first impulse response of the first channel; receiving via a destination antenna a second pilot sequence transmitted by an originating antenna through a second channel, and estimating a second impulse response of the second channel; receiving, via the reference antenna, a third pilot sequence modulated by the second impulse response and transmitted by the destination antenna, and estimating a combined impulse response of the first and second channels in succession; time reversing the combined impulse response; combining the time-reversed combined impulse response and the first impulse response; re-iterating the steps for a portion of the destination and originating antennas; and determining pre-equalization coefficients for the data signal from a set of the impulse response

Abstract: Pre-equalizing a data signal transmitted in frequency division duplex by an originating entity having a set of originating antennas to a destination entity having a set of destination antennas, including: transmitting a first pilot by a destination antenna; the originating entity estimating a first impulse response of a first channel; an iterative step including an originating antenna transmitting a second pilot modulated by the first impulse response; the destination entity estimating and time reversing a combined impulse response of the first and second channels; the destination antenna transmitting a third pilot modulated by the time-reversed response; estimating a composite response of the channels; re-iterating the iterative step for some originating antennas; and re-iterating the steps of transmitting a first pilot, estimating the first response, and the iterative step for some destination antennas; and determining pre-equalization coefficients for the data signal from a combination of a set of composit

Abstract: A communications method executed by a node of a telecommunications network, the method includes: a training step including determining a “transmission” filter as a function of a received training signal; and a data transmission step of transmitting data to a target node of the network while using the transmission filter as determined during the training step.