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 method for controlling the backscattering of an ambient signal emitted by an emitter device is described. The method is implemented by a transmitter device configured to backscatter the ambient signal and includes acquiring a measurement of power received from the emitter device, and evaluating a criterion consisting of at least checking whether a distance, counted from a position occupied by the transmitter device during the acquiring of the current measurement and in which a given reception quality value is attained for a signal obtained by backscattering the ambient signal, is in a given interval, where the distance of coverage being defined as a function of the measurement and the value. The ambient signal is backscattered only if the criterion is met.

Abstract: A method for monitoring at least one object associated with a receiver device. The method is implemented by the receiver device and includes: verifying detection of a tag, which backscatters ambient signals, that is associated with the at least one object; and identifying the at least one object as being attached to the receiver device if the tag, which backscatters ambient signals, is detected, and as being away from the receiver device if the tag is not detected. Use in checking that a set of objects associated with a device remains close to the device, and in detecting a potential distancing from an object (theft or forgetting).

Abstract: A method for monitoring objects, the objects including, respectively, tags that backscatter ambient signals. The method is implemented by a receiver device and includes: receiving a first backscattered signal originating from a first object, the first backscattered signal corresponding to an ambient signal and including a message having an identification datum relating to the first object; and determining the desired presence or the undesired presence of the first object in a geographical area as a function of the identification datum relating to the first object. Use for systems for monitoring objects, for example to detect proximity between objects that should not be close to one another.

Abstract: A method for correlating events is described. The method includes receiving a plurality of data streams, each of the streams having been emitted by an emitting source and including data representative of an event acquired by the source at the time of the emission and a marker representative of the backscattering of the data stream by a transmitting device. The method also includes determining a spatial and/or temporal correlation of the events from the markers.

Abstract: A method is described for determining a graph modelling a zone comprising at least one transmitting device for backscattering an ambient signal, emitted by a transmitting device, towards a receiving device for detection by said receiving device. The method includes obtaining at least one coverage area of said zone, said at least one coverage area having been determined for a location of said zone and corresponding to a datum identifying the transmitting device or devices detected by the receiving device when the transmitting device occupies said location. The method also includes determining a graph of which at least one vertex consists of said at least one coverage area, two vertices of said graph being connected by an edge if the coverage areas relating to said two vertices comprise at least one transmitting device detected in common.

Abstract: A method is described for determining a graph modelling a zone comprising at least one transmitting device for backscattering an ambient signal, emitted by a transmitting device, towards a receiving device (for detection by said receiving device. The method includes obtaining at least one coverage area of said zone, said at least one coverage area having been determined for a location of said zone and corresponding to a datum identifying the transmitting device or devices detected by the receiving device when the transmitting device occupies said location. The method also includes determining a graph of which at least one vertex consists of said at least one coverage area, two vertices of said graph being connected by an edge if the coverage areas relating to said two vertices comprise at least one transmitting device detected in common.

Abstract: The present invention relates to an ambient backscattering communication system (14), the communication system (14) comprising: an ambient backscattering transmitter (16) suitable for generating an ambient backscattering signal according to a first polarization from an ambient signal incident on the transmitter (16), an ambient backscattering receiver (18) suitable for detecting the ambient backscattering signal transmitted by the ambient backscattering transmitter according to a second polarization, and a reduction device (22) for reducing the interference between the ambient backscattering signal and an ambient signal incident on the receiver, the reduction device (22) controlling the first polarization and the second polarization and wherein at least one of said first and second polarizations is adjustable.

Abstract: A wireless communication device having a full-duplex architecture is described, the device comprising phase shifters integrated into transmitting chains and receiving chains, respectively, which are connected to basic antennae. Each transmitting/receiving chain is associated with a receiving/transmitting chain so as to form a pair of chains, with a connection circuit arranged between the chains of each pair. The device also includes at least one control module configured to control switching means and to activate/deactivate analogue means and digital means for cancelling interference and all or some of the transmitting/receiving chains so that the device is able to alternate between at least two different modes: a first full-duplex transmitting/receiving mode, and a second mode in which the device is able to reflect one or more transmission beams.

Abstract: A method for locating an object includes: obtaining at least one item of identification data of at least one object, the item of identification data coming from a backscattering of at least one ambient signal; and if the at least one ambient signal is transmitted following at least one uplink between at least one transmitter device and at least one receiver device, determining a location of the object from the item of identification data and at least one item of location data of the at least one transmitter device; or, if the at least one ambient signal is transmitted following at least one downlink between at least one transmitter device and at least one receiver device, determining a location of the at least one object from the item of identification data and at least one item of location data of the at least one receiver device.

Abstract: A process for generating at least one backscattering zone, by at least one transmitter device and to at least one receiver device, of an ambient radio signal emitted by at least one source; and a process for generating at least one reception zone, by the receiver device, of the backscattered ambient signal. The process for includes: determining an emission constraint, when it is respected by the source, for generating at least one backscattering zone in which the received electromagnetic power is greater than a determined threshold, called “backscattering threshold”, and/or generating at least one reception zone in which the received electromagnetic power is less than a determined threshold, called “reception threshold”; and transmitting, by the source, with respect to the emission constraint.

Abstract: A wireless communication device is described, having an analogue-digital hybrid architecture comprising passive phase shifters. The device includes a control module configured to control means for switching the communication device, such that the device is capable of alternating between three separate modes: a first/second mode in which each passive phase shifter is integrated into a transmission/reception chain, and a third mode in which each passive phase shifter is integrated into a transmission line.

Abstract: A control device for controlling the operation of a wireless communication device is described. The wireless communication device includes an antenna, a front-end module configured for transmitting and receiving signals according to a time-division multiplexing scheme, and switching means which can switch the front-end module between first and second modes in which the front-end module presents different impedances to the antenna The control device can be integrated in the communication device and includes a control module to control the switching means so that the front-end module alternates between the first and second modes so that the communication device backscatters an ambient signal.

Abstract: A control device for controlling the operation of a wireless communication device is described. The wireless communication device includes an antenna, a front-end module configured for transmitting and receiving signals according to a time-division multiplexing scheme, and switching means which can switch at least one transmission or reception chain of said front-end module between first and second modes in which the processing chain presents different impedances to the antenna. The control device can be integrated in the communication device and includes a control module to control the switching means so that the processing chain alternates between said first and second modes so that the communication device backscatters an ambient signal.

Abstract: The development relates to the detection of drones. The use of a cellular communication network by drones may cause problems because of interference generated by a user device located on-board a drone flying higher than antennas of the base stations. It is important, for a telecommunications operator, to be able to control use of the cellular communication network by drones. Methods allowing drones to be detected exist. These methods, although they allow a location of a drone to be determined, do not provide a satisfactory detection accuracy. Likewise, they do not allow two drones in similar positions to be distinguished between. The method is based on the use of control signals the characteristics of which are known and on the use of known properties of the transmission channel set up between the base station and the user device, to determine an altitude value that is accurate and reliable.

Abstract: A method for selection by an ambient backscatter system including a source as well as transmitting and receiving devices, the source being associated with a precoder for focusing signals towards the devices. Furthermore, the method includes, for a plurality of values ?_1, . . . , ?_N: a phase-shift, by the source, of one of the components of the precoder according to the value ?_i, so as to obtain a precoder Q_i; an emission, by the source, using the precoder Q_i; an acquisition, by the receiving device, of power measurements during non-backscattering and backscattering states, a determination, by the receiving device, of a value D1_i representative of a power deviation between the measurements. The method also includes a selection, by the receiving device, of a maximum value among the values D1_1, . . . , D1_N.

Abstract: A method is described for determining at least one location for backscattering, by at least one transmitter device and to at least one receiver device, of an ambient radio signal, the transmitter device being associated with a zone, a backscattering and a non-backscattering operating state, and a working frequency band. Further, the method is implemented by the transmitter device when it is in the non-backscattering state and comprises travel of the transmitter device in at least one part of the zone, during which the transmitter device acquires, in the working band and in at least one location of the part of the zone, a measurement of electromagnetic power received by the transmitter device, and compares the measurement with a determined threshold, the location associated with the measurement being determined as a location for backscattering if the measurement is greater than the threshold.

Abstract: A process for generating at least one backscattering zone, by at least one transmitter device and to at least one receiver device, of an ambient radio signal emitted by at least one source; and a process for generating at least one reception zone, by the receiver device, of the backscattered ambient signal. The process for includes: determining an emission constraint, when it is respected by the source, for generating at least one backscattering zone in which the received electromagnetic power is greater than a determined threshold, called “backscattering threshold”, and/or generating at least one reception zone in which the received electromagnetic power is less than a determined threshold, called “reception threshold”; and transmitting, by the source, with respect to the emission constraint.

Abstract: The present invention relates to an ambient backscattering communication system (14), the communication system (14) comprising: an ambient backscattering transmitter (16) suitable for generating an ambient backscattering signal according to a first polarization from an ambient signal incident on the transmitter (16), an ambient backscattering receiver (18) suitable for detecting the ambient backscattering signal transmitted by the ambient backscattering transmitter according to a second polarization, and a reduction device (22) for reducing the interference between the ambient backscattering signal and an ambient signal incident on the receiver, the reduction device (22) controlling the first polarization and the second polarization and wherein at least one of said first and second polarizations is adjustable.

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.