Abstract: The pulse train of a signal is modulated by a DPIM modulation involving a discrete random time parameter. A first processing is performed on the signal to deliver a sampled signal. A second processing is performed on the sampled signal, comprising a correlation processing including at least one elementary correlation processing with a correlation mask corresponding to the shape of at least part of a sampled pulse, and delivering second information items. A third processing is performed for detecting the pulses following a first pulse by taking account of the position of the first pulse, on packets of second information items, which are separated by a duration related to the discrete random parameter.

Abstract: The waveform of the signal varies according to the distance at which the signal was emitted, and several correlation signals are defined and correspond respectively to at least part of several sampled waveforms of the signal respectively emitted at several distances of different values so that the sum of the maxima of intercorrelations performed respectively between the various correlation signals and the various sampled waveforms is substantially constant over an interval including all the values of the distances. The correlation processing includes several elementary correlation processings respectively performed with the correlation signals and each delivering initial correlation values, as well as a summation of the homologous initial correlation values respectively delivered by the elementary correlation processings so as to obtain the correlation values.

Abstract: A device for decoding a direct sequence spread spectrum-encoded binary message includes a sampler that captures at least one sequence of binary samples corresponding to one bit of the transmitted message. The captured sequence of samples are applied to a filter matched to the spreading code used, thus making it possible to delete the spreading applied to the original message. The device further includes, at the output of the sampler, an error correction block including a memory storing a plurality of binary sequences corresponding to all of the possible values for a captured sequence of samples. A replacement circuit replaces the captured sequence of samples with the stored sequence, thereby minimizing the number of samples different from the captured sequence of samples, and allowing the stored sequence to be applied to the matched filter.

Abstract: A receiver device for a modulated signal, suited in particular to a transmission system using a binary carrier phase modulation by means of a binary message on which a direct sequence spread spectrum operation has been carried out, this device comprising a first analog radio frequency part, transforming the signal received into a low-frequency, demodulated signal, said demodulated signal being applied to a second digital part of said device comprising an analog-to-digital converter and a filter matched to the spreading code used in order to delete the spreading applied to the original message, said device being characterized in that it includes an additional filtering unit, arranged between the analog-to-digital converter and the matched filter, said filtering unit implementing a stochastic matched filtering operation in order to improve the signal-to-noise ratio at the input of said matched filter.

Abstract: A digital processing device is at the input of a radio frequency receiver chain, suited to a transmission system using a direct sequence spectrum spread, comprising analog-to-digital conversion means (ADC) performing an undersampling of a signal received, resulting in an overlapping of the wanted signal by the transmission channel noise, demodulation means connected to the output of the ADC, a low pass filter connected at the output of the demodulation means and a filter matched to the spreading code used, wherein the ADC includes a comparator capable of comparing the amplitude of the undersampled signal to a reference in order to carry out a quantizing of the 1-bit signal, said comparator bringing about the creation of a quantizing noise, and including an additional filtering unit arranged between the low pass filter and the matched filter, implementing a multi-noise, stochastic matched filtering operation.

Abstract: A digital processing device for a modulated signal, arranged at the input of a radio frequency receiver chain, suited in particular to a transmission system a direct sequence spread spectrum operation, comprising an analog-to-digital converter performing undersampling of the signal received, leading to an overlapping of the frequency range of the undersampled wanted signal by the frequency range of an interfering signal, demodulation means connected at the output of the analog-to-digital converter in order to bring the undersampled wanted signal back to baseband, a low pass filter connected at the output of the demodulation means and a filter matched to the spreading code used, and an additional filtering unit arranged between the low pass filter and the matched filter, for implementing a stochastic matched filtering operation to improve the signal-to-noise ratio at the input of the matched filter.

Abstract: The waveform of the signal varies according to the distance at which the signal was emitted, and several correlation signals are defined and correspond respectively to at least part of several sampled waveforms of the signal respectively emitted at several distances of different values so that the sum of the maxima of intercorrelations performed respectively between the various correlation signals and the various sampled waveforms is substantially constant over an interval including all the values of the distances. The correlation processing includes several elementary correlation processings respectively performed with the correlation signals and each delivering initial correlation values, as well as a summation of the homologous initial correlation values respectively delivered by the elementary correlation processings so as to obtain the correlation values.

Abstract: The pulse train of a signal is modulated by a DPIM modulation involving a discrete random time parameter. A first processing is performed on the signal to deliver a sampled signal. A second processing is performed on the sampled signal, comprising a correlation processing including at least one elementary correlation processing with a correlation mask corresponding to the shape of at least part of a sampled pulse, and delivering second information items. A third processing is performed for detecting the pulses following a first pulse by taking account of the position of the first pulse, on packets of second information items, which are separated by a duration related to the discrete random parameter.

Abstract: A device for decoding a direct sequence spread spectrum-encoded binary message includes a sampler that captures at least one sequence of binary samples corresponding to one bit of the transmitted message. The captured sequence of samples are applied to a filter matched to the spreading code used, thus making it possible to delete the spreading applied to the original message. The device further includes, at the output of the sampler, an error correction block including a memory storing a plurality of binary sequences corresponding to all of the possible values for a captured sequence of samples. A replacement circuit replaces the captured sequence of samples with the stored sequence, thereby minimizing the number of samples different from the captured sequence of samples, and allowing the stored sequence to be applied to the matched filter.

Abstract: A digital processing device is at the input of a radio frequency receiver chain, suited to a transmission system using a direct sequence spectrum spread, comprising analog-to-digital conversion means (ADC) performing an undersampling of a signal received, resulting in an overlapping of the wanted signal by the transmission channel noise, demodulation means connected to the output of the ADC, a low pass filter connected at the output of the demodulation means and a filter matched to the spreading code used, wherein the ADC includes a comparator capable of comparing the amplitude of the undersampled signal to a reference in order to carry out a quantizing of the 1-bit signal, said comparator bringing about the creation of a quantizing noise, and including an additional filtering unit arranged between the low pass filter and the matched filter, implementing a multi-noise, stochastic matched filtering operation.

Abstract: A digital processing device for a modulated signal, arranged at the input of a radio frequency receiver chain, suited in particular to a transmission system a direct sequence spread spectrum operation, comprising an analog-to-digital converter performing undersampling of the signal received, leading to an overlapping of the frequency range of the undersampled wanted signal by the frequency range of an interfering signal, demodulation means connected at the output of the analog-to-digital converter in order to bring the undersampled wanted signal back to baseband, a low pass filter connected at the output of the demodulation means and a filter matched to the spreading code used, and an additional filtering unit arranged between the low pass filter and the matched filter, for implementing a stochastic matched filtering operation to improve the signal-to-noise ratio at the input of the matched filter.

Abstract: A receiver device for a modulated signal, suited in particular to a transmission system using a binary carrier phase modulation by means of a binary message on which a direct sequence spread spectrum operation has been carried out, this device comprising a first analog radio frequency part, transforming the signal received into a low-frequency, demodulated signal, said demodulated signal being applied to a second digital part of said device comprising an analog-to-digital converter and a filter matched to the spreading code used in order to delete the spreading applied to the original message, said device being characterized in that it includes an additional filtering unit, arranged between the analog-to-digital converter and the matched filter, said filtering unit implementing a stochastic matched filtering operation in order to improve the signal-to-noise ratio at the input of said matched filter.