Matra

About: Matra is a based out in . It is known for research contribution in the topics: Signal & Detector. The organization has 1330 authors who have published 1216 publications receiving 17967 citations.

Radio transmission method using repeater stations with spectrum reversal

Abstract: The method is used to transmit digital signals by radio over a predefined frequency band between a base station and mobile stations. At least one repeater station is used to receive radio signals transmitted by the base station and to retransmit radio signals to the mobile stations over the same frequency band. The spectrum of the radio signals transmitted by the base station to the repeater station is reversed relative to the spectrum of the radio signals retransmitted by the repeater station to the mobile stations. The invention is particularly applicable to radiotelephone communications networks.

Electrically powered vehicles having motor and power supply contained within wheels

Abstract: An electrically powered vehicle, for example a bicycle, has a motor, controller and power supply contained within a wheel compartment. A cylindrical stator frame is fixed on the wheel axle, with an inner surface of the stator frame defining a space for housing the power supply and controller circuitry. A plurality of electromagnet stator segments are mounted on an outer surface of the stator frame. A cylindrical rotor frame is coupled to the axle through bearings. An inner surface of the rotor frame is coupled to the axle through bearings. An inner surface of the rotor frame supports a plurality of permanent magnets that surround the stator segments to form a radial air gap therebetween. Mounted to the outer surface of the rotor frame by appropriate supporting structure is a vehicle tire.

Analysis of multiple bit upsets (MBU) in CMOS SRAM

Abstract: Multiple Bit Upsets (MBU) have been studied in a 256 k CMOS static RAM irradiated at normal incidence and grazing angle. In normal incidence the sensitive areas have been identified with pulsed laser irradiation. The laser power thresholds have been determined for single to quadruple upsets in adjacent cells. Both experimental data and 3D simulations emphasize the role of delayed charge collection, by diffusion, and charge sharing between sensitive areas. Upset tracks have been recorded at grazing angle and used to determine the charge collection depth. These data revealed the existence of an LET threshold for MBU at grazing angle. As the ion LET increases different types of tracks are observed and correlated to the topological pattern in adjacent memory cells. This phenomenon is due to an unexpected charge collection mechanism, which couples adjacent sensitive areas and results in charge transfer between memory cells. The comparison with previous data on the same device indicates a strong influence of both ion energy and angle of incidence on the cross section, emphasizing the intrinsic limitation of standard characterizations with low energy ions. These results indicate that the basic assumption of a rectangular parallelepipedic volume does not take into account coupling phenomena, such as occurs in MBUs, and is no longer valid at grazing angle.

Method for selecting propagation paths retained for receiving messages transmitted by CDMA radiocommunication

Abstract: Each path is identified by a delay which is applied to at least one spreading sequence for determining a correlation between the received signal ans said spreading sequence. For each selected delay, a reception energy, contained in the CDMA signal consisting of a correlation between the received signal and a reference spreading sequence, is estimated. Delays to be tested are randomly chosen with a choice probability having a maximum for a delay substantially equal to the smallest selected delay. The delays thus chosen are tested by estimating the reception energy associated thereto. When the reception energy for a tested delay is greater than at least one of the reception energies associated to the previously selected delays, the tested delay is substituted for the previously selected delay having the smallest reception energy.