Digital frequency modulation receiver with frequency variation signal and demodulation method used by the same
AssigneeRichWave Technology Corp.
InventorZhuo Fu
Life of this patent
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Abstract
A digital frequency modulation receiver includes a phase capturer, an adder, a digital filter and a phase estimator. The phase estimator is used to generate a first phase value according to an input signal. The adder is coupled to the phase estimator for subtracting a second phase value from the first phase value to generate a phase difference. The digital filter is coupled to the adder for performing a filtering calculation with the phase difference so as to generate a frequency variation signal. The phase estimator is coupled to the digital filter and the adder so as to update the second phase value according to the frequency variation signal.
Claims15
A digital frequency modulation receiver comprising:
- a phase capturer configured to generate a first phase value according to an input signal;
- a first adder coupled to the phase capturer and configured to subtract a second phase value from the first phase value to generate a phase difference;
- a digital filter coupled to the first adder and configured to perform a filtering calculation with the phase difference to generate a frequency variation signal;
- and
- a phase estimator coupled to the digital filter and the first adder and configured to update the second phase value according to the frequency variation signal, the phase estimator comprising:
- a second adder coupled to the digital filter and a carrier-wave source and configured to add the frequency variation signal and a carrier-wave frequency to generate an estimated frequency;
- and
- a first integrator coupled to the second adder and configured to integrate the estimated frequency to update the second phase value.
A demodulation method used by a digital frequency modulation receiver, comprising:
- generating a first phase value according to an input signal;
- subtracting a second phase value from the first phase value to generate a phase difference;
- performing a filtering calculation to generate a frequency variation signal;
- and
- updating the second phase value according to the frequency variation signal by adding the frequency variation signal and a carrier-wave frequency to generate an estimated frequency, and integrating the estimated frequency to update the second phase value.
A digital frequency modulation receiver comprising:
- a phase capturer configured to generate a first phase value according to an input signal;
- a first adder coupled to the phase capturer and configured to subtract a second phase value from the first phase value to generate a phase difference;
- a digital filter coupled to the first adder and configured to perform a filtering calculation with the phase difference to generate a frequency variation signal, the digital filter comprising:
- a first multiplier coupled to the first adder and configured to multiply the phase difference by a first parameter to generate a first reference value;
- a second multiplier coupled to the first adder and configured to multiply the phase difference by a second parameter to generate a second reference value;
- a second integrator coupled to the first multiplier and configured to integrate the first reference value to generate a third reference value;
- and
- a third adder coupled to the second integrator and the second multiplier and configured to add the third reference value and the second reference value to generate the frequency variation signal;
- and
- a phase estimator coupled to the digital filter and the first adder and configured to update the second phase value according to the frequency variation signal.
Dependencies are inferred from the claim text.