Abstract: Apparatus and methods degarble a received broadband radio signal using spatial filtering. The apparatus and methods use various garbled versions of the signal delivered by parallel processing chains assumed to have the same transfer function. Automatic equalization (4d), at the level of the outputs of the processing chains (2a to 2g), is performed before the spatial filtering (3). The automatic equalization reduces disparities, innate or originate from drifts over time, between processing chains (2a to 2g), and uses a local test signal generator (5).

Abstract: The invention allows the detection and processing in a radio signal received by a receiver, of any signal of “pulsed” type present in radio signals applied to the input of a radiofrequency receiver, the receiver having an analogue/digital converter for performing the coding into digital on N bits of P successive samples of the analogue signal applied to the input of the receiver and a computer for processing the said digital signals, characterized in that on the basis of a histogram of the rate of occupancy of the digitized samples, graded in ranges Fx of amplitude-increasing sample levels, is determined, from among the ranges Fx, a range Fn onwards of which the total number of digitized samples Nnor contained in the ranges Fn and those below Fn is greater than or equal to a normality threshold Nn, Nn being a number predetermined as a function of the sensitivity of the detection of pulsed signals that one wishes to achieve.

Abstract: The invention relates to a method of transmitting a radionavigation signal which comprises coded and interleaved data; the signal comprises a pathway modulated by the coded and interleaved data and another pathway not modulated by these data, and the pathway not modulated by these data comprises a known code Cp making it possible to synchronize on reception the deinterleaving of the interleaved data.

Abstract: Method for the elimination in a receiver of an incident signal resulting from multipaths, characterized in that an array of 2n auxiliary sensors (2, 3, Ca to Cf), with n?3, is constructed around an antenna main sensor (1), these auxiliary sensors all being equidistant from the main sensor and regularly spaced apart, and, by successively taking the pairs of auxiliary sensors symmetric with respect to the main sensor to determine the direction of arrival of the signal resulting from the multipaths, the weighted combination of the signals arising from the n sensors is performed, the direction of the transmitter being known (ej?i).

Abstract: The invention relates to a method of processing an analog signal whose frequency spectrum exhibits over a determined bandwidth two main lobes separated by a frequency band where the power is negligible; it comprises a step of sampling according to a determined sampling frequency, and prior to this sampling step, a step consisting in performing a frequency translation of the two main lobes towards one another with a view to reducing the bandwidth and hence the sampling frequency.

Abstract: The invention relates to a method of acquisition of radio signals transmitted in particular by a satellite-based positioning system having a subcarrier, the acquisition of the signals being performed by a receiver having a channel for carrier correlation in-phase and quadrature, between the signal received and two respective in-phase and quadrature local carriers; a channel for subcarrier correlation on the basis of the signals at the output of the channel for carrier correlation with a local subcarrier; a channel for code correlation on the basis of the signals at the output of the channel for subcarrier correlation with the local codes provided by a digital generator of local codes; wherein in a first phase of acquisition, the channel for subcarrier correlation comprises two channels, in-phase and quadrature, between the signals at the output of the carrier correlation channel and two respective local subcarriers, in-phase and quadrature, with respect to the local code that are generated by a digitally cont

Abstract: Method for the elimination in a receiver of an incident signal resulting from multipaths, characterized in that an array of 2n auxiliary sensors (2, 3, Ca to Cf), with n?3, is constructed around an antenna main sensor (1), these auxiliary sensors all being equidistant from the main sensor and regularly spaced apart, and, by successively taking the pairs of auxiliary sensors symmetric with respect to the main sensor to determine the direction of arrival of the signal resulting from the multipaths, the weighted combination of the signals arising from the n sensors is performed, the direction of the transmitter being known (ej?i).

Abstract: The invention allows the detection and processing in a radio signal received by a receiver, of any signal of “pulsed” type present in radio signals applied to the input of a radiofrequency receiver, the receiver having an analogue/digital converter for performing the coding into digital on N bits of P successive samples of the analogue signal applied to the input of the receiver and a computer for processing the said digital signals, characterized in that on the basis of a histogram of the rate of occupancy of the digitized samples, graded in ranges Fx of amplitude-increasing sample levels, is determined, from among the ranges Fx, a range Fn onwards of which the total number of digitized samples Nnor contained in the ranges Fn and those below Fn is greater than or equal to a normality threshold Nn, Nn being a number predetermined as a function of the sensitivity of the detection of pulsed signals that one wishes to achieve.

Abstract: The invention relates to the antigarbling, in reception, of a broadband radio signal by a spatial filtering taking account of various garbled versions of the signal that are delivered by parallel processing chains assumed to have the same transfer function, such as for example, the individual processing chains associated with the radiating elements of an array antenna for receiving signals from GPS navigation satellites. It consists in carrying out, at the level of the outputs of the processing chains (2a to 2g), before the degarbling spatial filtering (3), an automatic equalization (4d) reducing the disparities between processing chains (2a to 2g), whether these disparities are innate or originate from drifts over time, this automatic equalization being accomplished by means of a local test signal generator (5).

Abstract: A method to eliminate interference occupying at least one part of the spectrum of one or more signals received by a network of N sensors comprises at least the following steps: subdividing each sample xi of signals into K frequency bands, weighting the samples xik obtained by subdivision, combining the different weighted coefficients Wik.