Abstract: A method for transmitting data packets having a heading followed by a data field. The data of the field is transmitted by groups of symbols. According to the OFDM technique, subcarriers modulated by the groups are generated. A frequency modulation of a carrier signal delivered by a linear ramp generator is produced with a set of modulated subcarriers. When the signal is received, mixing with a linear ramp results in subcarriers which are separated and then demodulated for supplying data. This is useful for transmitting data packets particularly in wide band networks.

Abstract: The disclosure relates to the transmission of information by packets on carrier frequencies, with data spreading and compression, between several transmitters and at least one receiver of one and the same communications network. In the network, the packets are constituted by a header followed by sub-packets transmitted in synchronism with the header and with a given periodicity, and this synchronism and this periodicity are the same for all the packets. Furthermore, all the sub-packets have the same structure as a standard sub-packet formed by mutually orthogonal segments. With such packets, the risks of overlapping are notably smaller than they were with standard packets. Application to the transmission of packets.

Abstract: The disclosure relates to the transmission of data by packets, in a network, with a search for an optimum use of the allocated band of frequencies. The packets are all formed by a header followed by an information field. The headers are all sent out on the same carrier frequency and the radio resources allocated to an information field are limited to a parallelogram demarcated by two first parallels corresponding to two fixed frequencies external to the frequencies allocated to headers and by two second parallels that have the same frequency/time slope for all the packets and whose position in time is deduced from the observation of the header. Thus, with knowledge of the resources used by the packets that are being transmitted, a terminal may send out a new packet as closely as possible to the packets that are being transmitted, but without any risk of interference with these packets. Application to transmission by packets.

Abstract: The disclosure relates to the transmission of data by packets on carrier frequencies with spreading and de-spreading of the data elements. In order to reduce the risks of overlapping among packets sent out by different transmitters, each packet to be transmitted is designed according to the characteristics of frequency spreading and/or code spreading of a common standard packet, constituted by successive segments all orthogonal to one another, the first segment comprising a header designed for identification. At reception the header, when it is found, activates the processing of the corresponding packet with de-spreading as a function of the characteristics of the spreading of the standard packet as they are known to the transmitter.

Abstract: The cross-point is intended for ATD multiplexing digital information in the form of packets of fixed lengths between two buses (A-B and C-D); it is constituted by: a first shift register (RAB), a first buffer register (RTE), a RAM (MRAM), a second buffer register (RTS), a second shift register (RCD), and logic circuits constituted by decision units for packet extraction (DE) and insertion (DI), associated with decision Tables (TEX and TIN), and a management unit of the RAM (GM). Packet extractions and insertions are effected in an asynchronous manner relative to each other.

Abstract: A method for transmitting data packets having a heading followed by a data field. The data of the field is transmitted by groups of symbols. According to the OFDM technique, subcarriers modulated by the groups are generated. A frequency modulation of a carrier signal delivered by a linear ramp generator is produced with a set of modulated subcarriers. When the signal is received, mixing with a linear ramp results in subcarriers which are separated and then demodulated for supplying data. This is useful for transmitting data packets particularly in wide band networks.