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US 5,949,280 AGranted
Multivalued FSK demodulation window comparator
AssigneeNEC Corporation
InventorTeruo Sasaki
Life of this patent
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AssigneeNEC Corporation
InventorTeruo Sasaki
Estimating the term…
A multivalued FSK demodulation window comparator includes an MSB comparator, an LSB comparator, a reception electric field strength detector, and a reference voltage generating circuit. The MSB comparator determines at least the polarity of a frequency shift of a radio frequency. The LSB comparator determines the absolute value of the frequency shift of the radio frequency. The reception electric field strength detector detects the strength of a radio signal and outputs a signal corresponding to the detected strength. The reference voltage generating circuit changes the reference voltages of the LSB comparator in accordance with an output voltage from the reception electric field strength detector. When the output voltage from the reception electric field strength detector is not higher than a predetermined level, a reference voltage from the reference voltage generating circuit changes.
A multivalued FSK demodulation window comparator comprising a most significant bit (MSB) comparator for determining at least a polarity of a frequency shift of a radio frequency, a least significant bit (LSB) comparator for determining an absolute value of the frequency shift of the radio frequency, a reception electric field strength detector for detecting a strength of a radio signal and outputting a signal corresponding to the detected strength, and a reference voltage generating circuit for changing reference voltages of said LSB comparator in accordance with an output voltage from said reception electric field strength detector, wherein when the output voltage from said reception electric field strength detector is not higher than a predetermined level, a reference voltage from said reference voltage generating circuit changes.
A multivalued FSK demodulation window comparator comprising a most significant bit (MSB) comparator for determining at least a polarity of a frequency shift of a radio frequency, a least significant bit (LSB) comparator for determining an absolute value of the frequency shift of the radio frequency, a reception electric field strength detector for detecting a strength of a radio signal and outputting a signal corresponding to the detected strength, and a reference voltage generating circuit for changing reference voltages of said LSB comparator in accordance with an output voltage from said reception electric field strength detector.
Dependencies are inferred from the claim text.