Method of date-stamping telemetry signals
AssigneeSafran Data Systems
InventorsYoucef Sini, Alain Thomas, Nicolas Pasternak
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Abstract
A method of date-stamping reception of digital data of a signal coherently modulating the carrier or sub-carrier, and utilizing the properties of such a modulation to improve the date-stamping thereof. Thereby accurately correcting the date-stamping of a pilot sequence (known pattern), and reducing the variance on the date-stamping of the transitions of the bits.
Claims15
A method of date-stamping of the reception of digital data of a modulated signal, said signal resulting from the modulation of a carrier or sub-carrier by a digital signal, the symbol rate of the digital signal being an integer sub-multiple N of the frequency of the carrier or sub-carrier, said method comprising the steps implemented by a processor of a telecommunications receiver consisting, after the reception and sampling of the modulated signal, in:
- coherent demodulation by means of a phase loop of a plurality of samples sm(k) of the modulated signal and obtainment of a plurality of demodulated samples sdm(k) and of the phase of the reconstituted carrier;
- combination of the plurality of demodulated samples sdm(k) with the simultaneous phase φ(k) of the reconstituted carrier
- determination of a plurality of dates on which the phase of the reconstituted carrier transitions to a determined value φ0, relative to the date of reception of at least one sample sm(k), according to a time offset during which the carrier rotates from φ(k) to φ0.
A telecommunications receiver receiving a modulated radio signal, said signal resulting from the modulation of a carrier or sub-carrier by a digital signal, the symbol rate of the digital signal being an integer sub-multiple N of the frequency of the carrier or sub-carrier, said receiver comprising:
- a demodulation unit configured for, after reception and sampling of the modulated signal, the:
- coherent demodulation by means of a phase loop of a plurality of samples sm(k) of the modulated signal and obtainment of a plurality of demodulated samples sdm(k) and of the phase of the reconstituted carrier;
- combination of the plurality of demodulated samples sdm(k) with the simultaneous phase φ(k) of the reconstituted carrier
- determination of a plurality of dates of transition to a determined value φ0 of the phase of the reconstructed carrier, relating to the reception date of at least one sample sm(k).
Dependencies are inferred from the claim text.