Abstract: A locating and communication method for a radio terminal by means of a satellite locating and communication system, which implements a first step, in the course of which the radio terminal transmits to a non-geostationary satellite a repeating sequence a predetermined number of times N for the same data packet, which is time-shifted by the same predetermined time shift ?? each time is provided. Subsequently, a satellite access and processing ground station determines the location of the radio terminal from the data packets with access, which are extracted from a listening signal digitized and dated by the satellite and from the same detected sequence associated with said radio terminal, and from the ephemerides of the satellite by using a technique for measuring angle or angles of arrival by means of sequenced interferometry associated with a technique for measuring Doppler drift or drifts.

Abstract: A radiofrequency system and to a data collection method includes at least one beacon, and at least one space platform or airborne platform with an adaptable antenna beam. The method comprises: a step wherein the platform emits an activation signal with a low directional antenna beam, each beacon responding with an access request, a step of generating a table comprising, for each item of equipment, a duration of visibility, a frequency band and a transmission duration, a step of defining a control plan scheduling the sequencing of the transmissions associated with directional antenna beam configurations of the platform, a step comprising: transmitting the times at which they are able to transmit to the items of equipment that emitted an access request, orienting the antenna beam of the platform according to the control plan, sending and storing the data.

Abstract: A radiofrequency system and to a data collection method includes at least one beacon, and at least one space platform or airborne platform with an adaptable antenna beam. The method comprises: a step wherein the platform emits an activation signal with a low directional antenna beam, each beacon responding with an access request, a step of generating a table comprising, for each item of equipment, a duration of visibility, a frequency band and a transmission duration, a step of defining a control plan scheduling the sequencing of the transmissions associated with directional antenna beam configurations of the platform, a step comprising: transmitting the times at which they are able to transmit to the items of equipment that emitted an access request, orienting the antenna beam of the platform according to the control plan, sending and storing the data.

Abstract: A locating and communication method for a radio terminal by means of a satellite locating and communication system, which implements a first step, in the course of which the radio terminal transmits to a non-geostationary satellite a repeating sequence a predetermined number of times N for the same data packet, which is time-shifted by the same predetermined time shift ?? each time is provided. Subsequently, a satellite access and processing ground station determines the location of the radio terminal from the data packets with access, which are extracted from a listening signal digitized and dated by the satellite and from the same detected sequence associated with said radio terminal, and from the ephemerides of the satellite by using a technique for measuring angle or angles of arrival by means of sequenced interferometry associated with a technique for measuring Doppler drift or drifts.

Abstract: A method for transmitting data in a telecommunication network having a satellite component and a terrestrial component, the data being organized into a set of packets having an identifier, the telecommunication network comprising at least one bearer, at least one satellite and at least one terrestrial station, the method comprises the steps of: transmission of a data packet having an identifier from said satellite, reception of the data packet by the bearer, transmission of a data packet having an identifier in response to a transmitted negative acknowledgement message by the terrestrial station. A method for receiving data to be implemented on a bearer, a method for transmitting data to be implemented on a terrestrial station, and an associated data transmission system are also provided.

Abstract: A method for transmitting data in a telecommunication network having a satellite component and a terrestrial component, the data being organized into a set of packets having an identifier, the telecommunication network comprising at least one bearer, at least one satellite and at least one terrestrial station, the method comprises the steps of: transmission of a data packet having an identifier from said satellite, reception of the data packet by the bearer, transmission of a data packet having an identifier in response to a transmitted negative acknowledgement message by the terrestrial station. A method for receiving data to be implemented on a bearer, a method for transmitting data to be implemented on a terrestrial station, and an associated data transmission system are also provided.

Abstract: A payload for augmentation satellite comprising an input channel suitable for receiving navigation signals transmitted by at least one navigation land earth station in a first frequency band and a plurality of output channels, each suitable for broadcasting navigation signals in a frequency band different from said first band and from other broadcasting bands, characterized in that it also comprises a navigation processor. A satellite comprising such a payload and an augmentation system comprising such a satellite is also provided.

Abstract: A system of geographical location of at least one radio signal transmitter located on the Earth's surface including: a set of satellites equipped with receiving antennas adapted for receiving said signals, forming a main extended interferometry device; an intersatellite relative metrology device for determining the relative positions of said satellites to one another, including at least one dedicated sensor for each satellite, and intersatellite communication means; a device for dating said received signals from said determining of the relative positions of said satellites to one another, issued by said intersatellite relative metrology device; a secondary interferometry device including at least one set of at least three antennas of a satellite; a ground base station; a device for transmitting measurements acquired on the satellites to the ground base station; and means of determining an absolute position of at least one of the satellites.

Abstract: A system for amplifying signals generated by a unit for generating signals of a satellite, the system including: a first pathway including a first bandpass digital filter with finite impulse response and a first digital/analog converter; frequency transposition means; an amplifying device; a second pathway including a second bandpass digital filter with finite impulse response; gain means disposed at the output of said second digital filter, a phase-slaved numerically-controlled oscillator, and a second digital/analog converter; and a recombiner device for summing the signals of said first and second pathways.

Abstract: A system for amplifying signals generated by a unit for generating signals of a satellite, the system including: a first pathway including a first bandpass digital filter with finite impulse response and a first digital/analog converter; frequency transposition means; an amplifying device; a second pathway including a second bandpass digital filter with finite impulse response; gain means disposed at the output of said second digital filter, a phase-slaved numerically-controlled oscillator, and a second digital/analog converter; and a recombiner device for summing the signals of said first and second pathways.

Abstract: A system of geographical location of at least one radio signal transmitter located on the Earth's surface including: a set of satellites equipped with receiving antennas adapted for receiving said signals, forming a main extended interferometry device; an intersatellite relative metrology device for determining the relative positions of said satellites to one another, including at least one dedicated sensor for each satellite, and intersatellite communication means; a device for dating said received signals from said determining of the relative positions of said satellites to one another, issued by said intersatellite relative metrology device; a secondary interferometry device including at least one set of at least three antennas of a satellite; a ground base station; a device for transmitting measurements acquired on the satellites to the ground base station; and means of determining an absolute position of at least one of the satellites.

Abstract: A payload for augmentation satellite comprising an input channel suitable for receiving navigation signals transmitted by at least one navigation land earth station in a first frequency band and a plurality of output channels, each suitable for broadcasting navigation signals in a frequency band different from said first band and from other broadcasting bands, characterized in that it also comprises a navigation processor. A satellite comprising such a payload and an augmentation system comprising such a satellite is also provided.

Abstract: An apparatus (A) is dedicated to generating sequences of signal coding elements within a signal transmission device (TD) of a CDMA network.

Abstract: An apparatus (A) is dedicated to generating sequences of signal coding elements within a signal transmission device (TD) of a CDMA network.

Abstract: A linearization circuit for a non-linear amplifier optimizes the overall efficiency (>50%). To achieve high efficiency the amplifier is operated in class "E" or class "F" and near saturation, causing phase and amplitude non-linearity. Phase non-linearity is corrected conventionally by a phase error signal generated in a feedback loop. Amplitude non-linearity is corrected by operating on the power supply modulator of the non-linear amplifier in an open loop configuration, using the input signal power. Further, more refined correction of amplitude non-linearity can be effected by operating on an automatic gain control amplifier on the input side of the non-linear amplifier, the gain of the automatic gain control amplifier being controlled by an amplitude error signal generated in a feedback loop.

Abstract: A pulse width modulation type power supply modulator capable of operating at high switching frequencies (>10 MHz) is achieved by eliminating resonant circuits which limit the maximal switching frequency. The modulator includes a power circuit including a power transistor, a first control circuit connected to the gate of the power transistor and a second control circuit connected to the output of the power circuit. In a preferred embodiment the active components are isolated from each other by areas of metalization on a printed circuit to minimize unwanted coupling and the electrical lengths are minimized.