Logarithmic detector and method of pre-charging an average filter on a logarithmic detector
AssigneeFreescale Semiconductor, Inc.
InventorLaurent Gauthier
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Abstract
The detector comprises a plurality of detection stages connected to a summator for providing a summation signal as a logarithmic representation of the input signal to a first input of a data slicer and an input of an average filter having an output connected to a second input of the data slicer. The data slicer has a data slicer output for providing an extracted digital data signal in dependence on a comparison of the summation signal and an output signal of the average filter. The average filter receives a first pre-charge voltage and a second pre-charge voltage depending on an output signal of a carrier detector circuit detecting a carrier signal of the input signal.
Claims21
A logarithmic detector for extracting a digital data signal from a received input signal, comprising:
- a plurality of detection stages;
- a summator;
- a data slicer;
- an average filter;
- wherein said plurality of detection stages is connected to said summator for providing a summation signal as a logarithmic representation of said input signal to a first input of said data slicer and an input of said average filter, said average filter having an output connected to a second input of said data slicer;
- said data slicer having an data slicer output for providing an extracted digital data signal in dependence on a comparison of said summation signal and an output signal of said average filter;
- said average filter receiving a first pre-charge voltage and a second pre-charge voltage depending on an output signal of a carrier detector circuit detecting a carrier signal of said input signal.
The logarithmic detector as claimed in claim 2, wherein said first pre-charge voltage is a voltage level present at said input of said average filter after said carrier detector output signal first indicates a presence of said carrier signal.
A method of pre-charging an average filter of a logarithmic detector, said detector comprising a plurality of detection stages connected to a summator for providing a summation signal as a logarithmic representation of said input signal, said method comprising
- receiving an input signal;
- applying a first pre-charge voltage to said average filter depending on an output signal of a carrier detector circuit;
- applying a second pre-charge voltage to said average filter depending on said output signal of said carrier detector circuit;
- and
- extracting a digital data signal from a comparison of said summation signal and an average filter output signal.
(canceled)
Dependencies are inferred from the claim text.