Abstract: A method and a system for multi-user transmission in a network, comprising at least on network control center NCC and one or more terminals, wherein the method comprises at least the following steps: determining the number of 4D-TDMA carriers as a function of the number and needs of the terminals, determining the type (SCPC or TDMA) and frequency band Bi of each of the 4D-TDMA carriers as a function of the terminals transmitting on the carriers, for each frame, dividing the band B into PTDMA transmission channels and into PSCPC service channels, each channel consisting of frames comprising a plurality of slots, STDMA slots and SSCPC slots, dynamically allocating a plurality of slots of a 4D-TDMA carrier according to the services required by each terminal, configuring the coding and modulation scheme of each slot by taking account of the quality of the received signals.

Abstract: A method and a system for multi-user transmission in a network, comprising at least on network control center NCC and one or more terminals, wherein the method comprises at least the following steps: determining the number of 4D-TDMA carriers as a function of the number and needs of the terminals, determining the type (SCPC or TDMA) and frequency band Bi of each of the 4D-TDMA carriers as a function of the terminals transmitting on the carriers, for each frame, dividing the band B into PTDMA transmission channels and into PSCPC service channels, each channel consisting of frames comprising a plurality of slots, STDMA slots and SSCPC slots, dynamically allocating a plurality of slots of a 4D-TDMA carrier according to the services required by each terminal, configuring the coding and modulation scheme of each slot by taking account of the quality of the received signals.

Abstract: In the field of satellite communication systems, a method is provided for managing communication resources allocated by central control equipment to the various terminal communication devices within a global satellite communication system. In particular, the management of communication resources by way of the monitoring of the equivalent isotropically radiated power transmitted by a terminal of the satellite communication system is provided.

Abstract: A method of emission of a frequency synchronization signal comprises a first step of determining at least two first emission frequencies respectively associated with at least two first intervals separated temporally by a first duration. The first temporal intervals are of identical duration. The first durations are identical for identical first frequencies and the first durations are different for different first frequencies. The method also comprises a second step of emitting at least one synchronization signal in the first temporal intervals and by using the first frequency, the signal emitted in the first intervals being identical.

Abstract: A communication system using the DVB-S2 standard, and its associated frame structure, comprises at least two users Ui, characterized in that the super-frame ST1 associated with the first user U1 is composed of at least one frame T1 each composed of at least one header, of a data part, the said super-frame ST1 comprising a number d1 of “dummy” variable size frames consisting of s1 slots, the super-frame ST2 associated with the second user U2 is composed of one or more frames T2 each composed of at least one header, of a data part, the said super-frame ST2 comprising a number d2 of “dummy” variable size frames consisting of s2 slots, the system comprises a module NCC adapted for determining the number d1 and the number d2 of dummies to be introduced so that the temporal duration of ST2 is equal to the temporal duration of ST1.

Abstract: A satellite transmission system comprises at least: one satellite and two stations comprising transmission means transmitting simultaneously and in the same frequency band a first, high-bit-rate signal and a second, low-bit-rate signal, the second signal allowing changing of frequency of the carrier signal. The station(s) include reception means for receiving simultaneously and in the same frequency band the first and second signal. The system includes means for detecting interference on the frequency band. The transmission means and reception means respectively switch the transmission and reception of the second signal from a low bit rate to a medium bit rate and deactivate the transmission of the first signal in presence of interference, and the transmission means and reception means respectively switch the transmission and reception of the second signal from a medium bit rate to a low bit rate and activate transmission of the first signal in absence of interference.

Abstract: A system and method for modifying the carrier frequency of first and second signals associated with first and second sequences, respectively, of consecutive time intervals, comprises: first means determining two carrier frequencies respectively associated with each of the two signals based on one time interval or at least two consecutive and continuous time intervals, said time interval(s) belonging to a sequence of consecutive time intervals of known duration; and second means determining a first time interval or at least two first consecutive time intervals belonging to the first sequence, based on a second time interval belonging to the second sequence, by establishing a temporal correspondence between each end of said time interval of said second sequence and an interval of said first sequence including this end. The first means determines said carrier frequencies based on one time interval or at least two consecutive time intervals, belonging to said first sequence.

Abstract: The method of transmission between a transmitter and a receiver using a mode of adaptive modulation and coding, wherein the modulation and coding are selected based on the comparison of a characteristic variable of the signal to noise ratio measured by the receiver with a threshold value plus a margin, which margin is variable depending on the prior change in the signal to noise ratio. The margin changes based on a statistical function of a higher order than 1 of the characteristic variable of the signal to noise ratio measured by the receiver over at least one time horizon.

Abstract: A method for enciphering a DVB-S2 frame or super-frame, including at least a first type of frame modulated with a first modulation M1 and a second type of frame modulated with a second modulation M2, comprises at least the following steps: inserting into the DVB-S2 super-frame a number of dummy frames “n” of DVB-S2 structure of length n in order to obtain a structure ST of the same defined duration T, for several given configurations, the size of the dummy frame “n” is defined in the field 29 of the code word of the PLS of a DVB-S2 frame, a dummy frame “n” being composed of a PLHeader and of n?1 slots of 90 complex symbols; and applying an enciphering algorithm to the super-frame thus obtained.

Abstract: In the field of satellite communication systems, a method is provided for managing communication resources allocated by central control equipment to the various terminal communication devices within a global satellite communication system. In particular, the management of communication resources by way of the monitoring of the equivalent isotropically radiated power transmitted by a terminal of the satellite communication system is provided.

Abstract: An antenna system includes at least one antenna and one X-Y mount, said mount being composed of at least three mechanical elements, the first element being a base, the second element being a lower box, the third element being a upper box, the antenna of the system being fixed to the upper box. The components of the antenna downlead are distributed in the various elements composing the X-Y mount, an OMT type junction included in the upper box enabling separation of the components of the downlead into two separate paths, a first path called the ascending path comprising components for amplifying and processing signals to be transmitted by the antenna, a second path called the descending path comprising components for processing and amplifying signals received by the antenna, the components associated with these paths being placed on either side of the various elements of the X-Y mount.

Abstract: A communication system using the DVB-S2 standard, and its associated frame structure, comprises at least two users Ui, characterized in that the super-frame ST1 associated with the first user U1 is composed of at least one frame T1 each composed of at least one header, of a data part, the said super-frame ST1 comprising a number d1 of “dummy” variable size frames consisting of s1 slots, the super-frame ST2 associated with the second user U2 is composed of one or more frames T2 each composed of at least one header, of a data part, the said super-frame ST2 comprising a number d2 of “dummy” variable size frames consisting of s2 slots, the system comprises a module NCC adapted for determining the number d1 and the number d2 of dummies to be introduced so that the temporal duration of ST2 is equal to the temporal duration of ST1.

Abstract: The method of transmission between a transmitter and a receiver using a mode of adaptive modulation and coding, wherein the modulation and coding are selected based on the comparison of a characteristic variable of the signal to noise ratio measured by the receiver with a threshold value plus a margin, which margin is variable depending on the prior change in the signal to noise ratio. The margin changes based on a statistical function of a higher order than 1 of the characteristic variable of the signal to noise ratio measured by the receiver over at least one time horizon.

Abstract: A system for synchronizing a satellite pointing device using the transmission of a satellite synchronization signal in a set of contiguous time intervals, comprises first means of selection of at least two time intervals belonging to the set. The system also comprises second means of selection of at least two distinct transmission frequencies, each transmission frequency being associated with one of the said selected time intervals. Finally the system comprises means for modulating the synchronization signal in the selected time intervals by using the transmission frequency respectively associated with the time interval and means for demodulating the synchronization signal received.

Abstract: A method of emission of a frequency synchronization signal comprises a first step of determining at least two first emission frequencies respectively associated with at least two first intervals separated temporally by a first duration. The first temporal intervals are of identical duration. The first durations are identical for identical first frequencies and the first durations are different for different first frequencies. The method also comprises a second step of emitting at least one synchronization signal in the first temporal intervals and by using the first frequency, the signal emitted in the first intervals being identical.

Abstract: An antenna system includes at least one antenna and one X-Y mount, said mount being composed of at least three mechanical elements, the first element being a base, the second element being a lower box, the third element being a upper box, the antenna of the system being fixed to the upper box. The components of the antenna downlead are distributed in the various elements composing the X-Y mount, an OMT type junction included in the upper box enabling separation of the components of the downlead into two separate paths, a first path called the ascending path comprising components for amplifying and processing signals to be transmitted by the antenna, a second path called the descending path comprising components for processing and amplifying signals received by the antenna, the components associated with these paths being placed on either side of the various elements of the X-Y mount.