US 2009/0023409 A1 · Receiving device

Abstract

A waveform shaping circuit wave-shapes a demodulated signal after FM demodulation to generate a binary value. A smoothing circuit smoothes the demodulated signal to generate a reference voltage. A comparator compares the reference voltage with the demodulated signal to output the binary value. A potential difference limiting circuit determines whether a potential difference between the demodulated signal and the reference voltage exceeds a set voltage. When the potential difference exceeds the set voltage, the potential difference is controlled to a value less than the set voltage. At the initiation of signal reception or after a jamming signal stops, the reference voltage follows the demodulated signal, thus allowing data reception to rapidly begin.

Claims13

Dependent claims

A receiving device comprising:

a frequency modulation (FM) detector for FM-demodulating a received signal to form a demodulated signal;
a smoothing circuit for smoothing the demodulated signal to generate a reference voltage;
and
a waveform shaping circuit including:
a comparator comparing the reference voltage with the demodulated signal so as to binarize the demodulated signal;
and
potential difference limiting means for limiting a potential difference between the demodulated signal and the reference voltage to less than a set voltage set based upon a voltage variation width of a portion of the demodulated signal acquired when the FM detector FM-demodulates an object signal contained in the received signal.

4 more elements

A receiving device for recovering an object signal from a received signal, the object signal modulated according to frequency variation width between a first object frequency and a second object frequency in a frequency zone, the received signal susceptible to a jamming signal having a jamming frequency in the frequency zone, the device comprising:

a frequency modulation (FM) detector for FM-demodulating the received signal in the frequency zone to form a demodulated signal;
a smoothing circuit for smoothing the demodulated signal according to a time constant to generate a reference voltage associated with the first object frequency, the second object frequency and, when present, the jamming frequency;
and
a waveform shaping circuit including:
a comparator comparing the reference voltage with the demodulated signal so as to binarize the demodulated signal;
and
potential difference limiting means for limiting a potential difference between the demodulated signal and the reference voltage to less than a set voltage, the set voltage based on a voltage variation width of a portion of the demodulated signal associated with the object signal only, the voltage variation width based on the frequency variation width.

4 more elements

Dependencies are inferred from the claim text.

Receiving device

Life of this patent

Receiving device

Life of this patent

Abstract

Claims13