Centre National Detudes Spatiales

Thales

Jean-Luc Issler

Lionel Ries

Christophe Macabiau

Olivier Julien

Nicolas Martin

Marc Revol

Laurent Lestarquit

Jose-Angel Avila-Rodriguez

Guenter W Hein

Blandine Coatantiec

To receive a radio navigation signal modulated by a modulation waveform, the modulation waveform comprising a component BOC(n,m) and a component BOC(n,m), nbeing strictly less than n, a correlation is performed between a prompt local waveform and the modulation waveform and a correlation is performed between a shifted (forward or backward) local waveform and said modulation waveform, over a time interval of duration T. The prompt local waveform is generated in the guise of a binary waveform comprising over said time interval at least one waveform segment BOC(n,m) of a total duration of (1&#x2212;&#x3b1;)T over said time interval, &#x3b1;being a parameter greater than or equal to 0 and strictly less than 1. The shifted local waveform is generated in the guise of a binary waveform comprising over said time interval at least one waveform segment BOC(n,m) of a total duration of &#x3b1;T over said time interval, B being a parameter strictly greater than 0 and less than or equal to 1, and &#x3b1;being different from &#x3b1;.

Method of reception and receiver for a radio navigation signal modulated by a CBOC or TMBOC spread waveform

A spread-spectrum signal comprises a spreading waveform modulating a carrier wave and containing a real linear combination of a first waveform at a first waveform rate and a second waveform at a second waveform rate, the first waveform rate being distinct from the second waveform rate and both waveform rates being distinct and non-zero. The linear combination of the first and the second waveform is modulated with at least one binary sequence comprising a signal identification code.

Spread spectrum signal

Disclosed is a method for receiving a radionavigation signal modulated by a composite waveform, the composite waveform comprising a linear combination with real-valued coefficients of a BOC(n,m) component and a BOC(n,m) component, ndiffering from n; in which a correlation is performed between a local waveform and the composite waveform over a time interval of duration T, wherein the local waveform is a binary waveform, formed over the time interval by an alternating succession comprising at least one BOC(n,m) waveform segment and at least one BOC(n,m) waveform segment, the at least one BOC(n,m) segment having a total duration of &#x3b1;T, &#x3b1; being strictly betweenand, the at least one BOC(n,m) segment having a total duration of (&#x2212;&#x3b1;)T.

Method of reception and receiver for a radio navigation signal modulated by a CBOC spread wave form

The invention relates to methods of processing signals subjected to interference. It consists, when this signal is formed of a first wideband channel and of a second narrowband channel modulating one and the same carrier in which these signals are cut off for the duration of the interference, in using a single phase loop and a single code loop to process these two channels simultaneously. It makes it easier to process signals in satellite based navigation systems of the GPS type when they are scrambled by the DME-type distance measuring system signals, as well as more generally making it possible to increase the robustness of the processing by joint processing of the bands broadcast to the users.

Method of signal processing in the presence of interference

The present invention relates to a process for the autonomous reduction of acquisition and tracking thresholds of carriers received in orbit by a receiver accessing an orbital navigator inside or outside said receiver, the latter having at least one phase loop. The phase loop, which is responsible for the acquisition and/or tracking of the carrier, is 'pushed' by the fine speed aid and takes up the error between the real speed and the calculated speed. The search for the Doppler frequency of the carrier received takes place around a frequency prediction maintained by the fine speed aid coming from the orbital navigator.

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Toulouse, France

Jean-Luc Issler