摘要:
A method is devoted to synchronizing the transmission of user signals within a single-frequency hybrid network comprising at least one transmission satellite (SAT) and regenerative emitters (E1-E6) tasked with retransmitting received user signals to user terminals (T1, T2), using the same frequency and the same waveform. This method consists of temporally shifting, with respect to a time marker (TM) corresponding to the moment when a chosen element of the user signals arrives at a terrestrial reference arc (RA) from said satellite (SAT), the moment when the user signals received by each emitter (E1-E6) are retransmitted, by a local duration which is a function of the respective positions of the emitter and the satellite (SAT) with respect to a chosen reference position (RP) on said arc (RA), so that the same user signals retransmitted by the satellite (SAT) and the emitter (Ei) reach a user terminal (T1, T2) at roughly the same time.
摘要:
A method is devoted to synchronizing the transmission of user signals within a single-frequency hybrid network comprising at least one transmission satellite (SAT) and regenerative emitters (E1-E6) tasked with retransmitting received user signals to user terminals (T1, T2), using the same frequency and the same waveform. This method consists of temporally shifting, with respect to a time marker (TM) corresponding to the moment when a chosen element of the user signals arrives at a terrestrial reference arc (RA) from said satellite (SAT), the moment when the user signals received by each emitter (E1-E6) are retransmitted, by a local duration which is a function of the respective positions of the emitter and the satellite (SAT) with respect to a chosen reference position (RP) on said arc (RA), so that the same user signals retransmitted by the satellite (SAT) and the emitter (Ei) reach a user terminal (T1, T2) at roughly the same time.
摘要:
In a radiocommunications system having physical channels each including at least one logical channel, the invention proposes transmitting both the means for acquiring and tracking synchronization and the system information addressed to user stations in a single logical channel referred to as the “synchronization” channel. For this purpose, the synchronization channel carries a repeated detection word (1) together with system information (2) between repeats of the detection word. The system information is subjected to spreading prior to being transmitted over the synchronization channel. The invention makes it possible to limit the amount of system resources that are devoted to providing the functions of synchronization and of broadcasting system information.
摘要:
A terrestrial repeater, comprising i) an interface means configured to receive a first data stream originating from a first satellite transmission network, a second data stream originating from a second transmission network, and a third data stream originating from a third terrestrial transmission network, and to transform the received streams into data packets; ii) a first processing means configured to select at least one part of the data packets of at least one of the first, second, and third streams received, and to process each selected stream portion to place the data packets it comprises into a selected broadcast format; and iii) a second processing means configured to combine the selected and processed stream portions to constitute a set of packets to be broadcast, convert the set of packets into at least one radio frequency signal, and amplify the at least one radio frequency signal in order to broadcast wirelessly towards at least one radio communication terminal.
摘要:
Methods for controlling orthogonal frequency division multiple access (OFDMA) communications over satellite links. The methods include estimating a differential delay in a satellite spotbeam between a mean propagation delay in the spotbeam and a propagation delay between a user terminal in the spotbeam and a satellite, estimating an overlap between an OFDMA uplink frame and an OFDMA downlink frame as a result of the differential delay, and providing a guard band in the OFDMA uplink frame and/or the OFDMA downlink frame to reduce an overlap between remaining portions of the OFDMA uplink frame and the OFDMA downlink frame other than the guard band. Corresponding systems and devices are also disclosed.
摘要:
Methods for controlling orthogonal frequency division multiple access (OFDMA) communications over satellite links. The methods include estimating a differential delay in a satellite spotbeam between a mean propagation delay in the spotbeam and a propagation delay between a user terminal in the spotbeam and a satellite, estimating an overlap between an OFDMA uplink frame and an OFDMA downlink frame as a result of the differential delay, and providing a guard band in the OFDMA uplink frame and/or the OFDMA downlink frame to reduce an overlap between remaining portions of the OFDMA uplink frame and the OFDMA downlink frame other than the guard band. Corresponding systems and devices are also disclosed.
摘要:
Relative and controlled sealing between a pipe (1) and a ceramic tube (7) utilizes a cylindrical chamber (5) that is attached in a sealed manner to the pipe (1), and to one end of the ceramic tube that is placed inside the chamber. At least two sets of sealing fixtures (3, 3′) are placed in an annular space between the ceramic tube and the chamber. A crosspiece (4) is interposed between the two sets sealing of fixtures (3, 3′). A metal mating flange (6) is pressed against a compression ring (4′) to compress the sealing fixtures (3, 3′). Injection of a fluid (8) between the two sets of sealing fixtures (3, 3′) applies a pressure differential that is determined on each of the fixtures.
摘要:
Device for connecting a heat exchange pipe (4), whereby said pipe (4) is positioned between walls (11) that are located on both sides of pipe (4), intended for heating and/or cooling a reactor, whose internal pressure is considerably higher than the atmospheric pressure and than the pressure that prevails inside said pipe (4), and said reactor, whereby said device comprises a series of cooperating means that comprise: means for connecting this pipe (4) and jacket (2a) of said reactor, whereby said means comprise a packing box (21, 22, 23), a flange (28) that is attached to jacket (2a) of the reactor by means of a joint (18), a bellows (25) that is placed between packing box (21, 22, 23) and said flange (28) to ensure a relatively flexible connection between pipe (4) and jacket (2a) of the reactor. FIG. 3 to be published.
摘要:
The invention relates to methods of introducing a heterologous DNA sequence into a mouse embryonic stem cell wherein the DNA sequence is inserted by homologous recombination into a villin gene/I-SceI hybrid by creating a double strand break with I-SceI meganuclease. Subsequently, the mouse embryonic stem cells can be used to generate a transgenic mouse comprising the heterologous DNA sequence. Additionally, the methods can be used for gene replacement in ovo where a mouse oocyte containing a villin gene/I-SceI hybrid within its genome exists or is first generated. More generally, the methods can be used for the targeted insertion of a heterologous DNA sequence into any cell containing a villin gene/I-SceI hybrid sequence within its genome.
摘要:
A terrestrial repeater (RT), comprising i) interface means (MI) having the function to receive a first data stream originating from a first satellite type transmission network (R1), a second data stream originating from a second transmission network (R2), and a third data stream originating from a third terrestrial type transmission network (R3), and to transform the said received streams into data packets; ii) first processing means (MT1) equipped to select at least one part of the data packets of at least one of the first, second, and third streams received, and to process each selected stream portion so as to place the data packets it comprises into a selected broadcasting format; and iii) second processing means (MT2) having the function to combine the stream portions selected and processed in order to constitute a set of packets to be broadcast, then to convert the said set into at least one radio frequency, and to amplify the said radiofrequency signal with a view to its broadcast via waves towards at least one radio communication terminal (UE).