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AssigneeElectronique Marcel Dassault & Centre National d'Etudes Spatiales
InventorsMichel Geesen, Jacques Mourant, Daniel P. Ludwig
Estimating the term…
In a satellite which asynchronously receives radio frequency signals from a lurality of beacons scattered at the surface of the earth, each signal received has a pure carrier wave portion followed by a phase modulated message carrying portion. The frequencies of the signals are not known within a predetermined frequency band. The satellite has a plurality of essentially identical processing units which each receive on their input all the signals present at any given instant in the input frequency band. Each processing unit has a phase locked loop which may be progressively tuned to the frequency of one of these input signals in response to a frequency estimate of this signal to which the operating frequency of the phase locked loop is preset. This frequency estimate is updated until the phase lock occurs on this input signal, ready for demodulation of the message part to begin. The estimate frequencies are derived from an input band frequency spectrum analyzer. A command unit selectively allocates each new frequency estimate to a respective processing unit as a result of a comparison therof with the previously allocated frequency estimates to accelerate the tuning of the processing units and prevent any duplication of the processing of a same input signal.
Apparatus for acquiring and processing a plurality of input signals received asynchronously from a plurality of sources comprising:
Apparatus for acquiring and processing a plurality of input signals received asynchronously from a plurality of sources, said signals including respective frequency carriers within a predetermined frequency range, comprising:
A method for acquiring and processing a plurality of input signals received asynchronously at a station from a plurality of sources, comprising:
Apparatus for acquiring a plurality of input signals received asynchronously at unknown frequencies within a known input frequency band comprising:
Apparatus for acquiring input signals of unknown frequency received asynchronously within a predetermined input frequency band, comprising:
Apparatus for acquiring input signals received asynchronously at frequencies unknown within an input frequency band comprising:
Apparatus for acquiring a plurality of input signals received asynchronously at respective unknown frequencies within a known input frequency band comprising:
Dependencies are inferred from the claim text.