Commissariat a L'energie Atomique

Xantima LLC

Other

Bernard Piaget

Didier Lattard

Christophe Boulanger

Laurent Ouvry

Norbert Daniele

Didier Varreau

Jean-Francois Piquard

Charles Fort

Marc Laugeois

Jean-René Lequepeys

Sébastien Leveque

Jean-Ren&eacute; Lequepeys

Jacques Vacher

Patrick Le Masson

Michel Martin

Jean-Charles Dubuis

Jean Rene Lequepeys

Roselino Lionti

A method of parallel suppression of interference, and corresponding stage and receiver is disclosed according to the invention, parallel suppression of interference is carried out starting from the signals selected by a maximum likelihood criterion based on the calculation of a metric and the search for the smallest possible metric.

Method of receiving CDMA signals with parallel interference suppression, and corresponding stage and receiver

The invention relates to a device for exchanging digital data between several sources and at least one hub in a CDMA system, characterised in that it comprises a number n of digital transmission/reception circuits () installed in parallel, each circuit () comprising a transmitter () comprising means of generating an integer number Nof codes that will be used for spectral spreading of data to be transmitted and a receiver () comprising means () of detecting the access of new sources to the CDMA system transmission channel and means () of generating synchronisation signals and power control signals corresponding to each detected new source.

Digital data exchange device in a CDMA system

This invention relates to parallel architecture digital filter and signal receiver with spectrum spreading using such a filter, the filter may have p shift registers (R, R) with means for calculating a weighted sum of stored samples in the registers, p weighted sums (S, S) may be obtained and recombined with number p being, for example, equal to 2.

Parallel architecture digital filter and spread spectrum signal receiver using such a filter

The invention relates to a device for exchanging digital data between several sources and at least one hub in a CDMA system, characterized in that it comprises a number n of digital transmission/reception circuits () installed in parallel, each circuit () comprising a transmitter () comprising means of generating an integer number Nof codes that will be used for spectral spreading of data to be transmitted and a receiver () comprising means () of detecting the access of new sources to the CDMA system transmission channel and means () of generating synchronization signals and power control signals corresponding to each detected new source.

A method for receiving spectrum spreading signals using a Doppler-effect frequency-shift correction generates a corrective signal based on an estimation of a modulation period related to the Doppler effect detected in a preamble portion of a received signal. The corrective signal is used for correcting an information portion of the received signal. Base band digital signals are operated upon by using the DOT and CROSS components.

Method for receiving spectrum spreading signals with frequency shift correction

The present invention relates to a method for receiving CDMA signals with synchronization being obtained through double delayed multiplication, and an associated receiver. According to the invention, the correlation signal undergoes double delayed multiplication. Synchronization is established on the signal thus generated. Applied to digital communications, in particular with mobile phones.

Method for receiving CDMA signals with synchronization resulting from delayed double multiplication and corresponding receiver

A method for receiving spectrum spreading signals with frequency shift correct in which the modulation period related to the Doppler effect is estimated by using a preamble and a correction signal is elaborated, the signal transmitting the information is then corrected by this correction signal.

Method for receiving spectrum spread signals with frequency offset correction

A circuit able to operate either as a direct sequence spread spectrum differential signal emitter, or as a generator of interference signals corresponding to multiple access noise. The circuit employs a clock signal formation and data processing module, a differential coding module, a multiplexing module, and a direct sequence spread module when operating as a spread spectrum emitter, and has an additional amplification-inversion module for use when generating an interference signal.

Circuit for direct sequence spread spectrum digital transmissions with generation of an interference signal

A differential receiver which receives a signal corresponding to transmission of a carrier modulated by symbols S.sub.k, where k is an integer designating an order of the symbol, each symbol S.sub.k has a duration Ts and carries information, and the symbols S.sub.k have been multiplied by a psuedorandom sequence. The differential receiver includes a first processing channel configured to receive a first part of the transmitted signal in phase with the carrier to generate samples I.sub.k and delayed samples I.sub.k-1. The receiver further includes a second processing channel configured to receive a second part of the transmitted signal in phase quadrature with the carrier to generate samples Q.sub.k and delayed samples Q.sub.k-1. In addition, the receiver includes a multiplication circuit configured to generate a signal Dot(k) equal to I.sub.k I.sub.k-1 +Q.sub.k Q.sub.k-1 and a signal Cross(k) equal to Q.sub.k I.sub.k-1 -I.sub.k Q.sub.k-1, a calculating mechanism configured to calculate, for each order k of a symbol, the following equation: E=[Dot(k).sup.2 +Cross(k).sup.2 ].sup.1/2, and configured to calculate a mean E.sup.moy, a weighting circuit having two multipliers configured to respectively multiply the signal E.sup.moy and the signals Dot(k) and Cross(k) to obtain a mean signal Dot(k).sup.moy and a mean signal Cross(k).sup.moy, and a circuit configured to receive the mean signal Dot(k).sup.moy and the mean signal Cross(k).sup.moy supplied by the calculating mechanism to integrate the mean signals on the time of a symbol and restore the corresponding information.

Process for the transmission of information by pulse response and the

A Differential receiver of direct sequence spread spectrum signals, wherein, the intermediate frequency stage comprises N filtering and amplifying channels in N separate bands. The amplification of a channel is adjusted so that the power levels delivered by the channels correspond to a predetermined power distribution law.

Differential receiver of direct sequence spread spectrum signals

The circuit has two parallel channels for the processing of two components in phase (I) and in quadrature (Q). Each channel has filtering means (50(I)) and delay means (60(I)). The circuit also incorporates a multiplication circuit (70), an integration circuit (80) and a programming circuit (90). Several circuits of this type can be connected in cascade.

Digital circuit for differential receiver for direct sequence spread

Multielement ultrasonic probe production process connecting a piezoelectric ceramic block incorporating an upper conductive layer and a lower layer to two printed circuits having a metallized face and a face provided with conductive strips, electrically connecting one of the conductive strips to one of the faces of the printed circuits and the other conductive strip to the other face of said circuits, cutting out said block and the upper part of said circuits so as to form equidistant piezoelectric elements and mechanically insulating them from one another, as well as the connections with respect to each element. The invention has application to medical echography.

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Venon, France

Bernard Piaget