METHOD OF DEMODULATION OF FREQUENCY-MODULATED SIGNALS Russian patent published in 2015 - IPC H03D3/00 

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to radio communication and can be used for signals processing at reception of frequency-modulated signals. The method of demodulation of frequency-modulated signals consists in conversion of the frequency-modulated signal into digital form and obtaining of two quadrature signals. Then the counts of quadrature signals are passed through the low frequency digital filter, the value of the module of signal counts is calculated, also each quadrature signal in addition is passed through the digital differentiating filter the pulse characteristic of which corresponds to derivative of the pulse characteristic of the low frequency filter, the counts of signals from outputs of the low-frequency and differentiating filters thins out, values of the module of signal counts are calculated from the thinned-out counts from the output of the low-frequency filter then the smoothing filtration of the signal module is performed, the thinned-out real counts from the output of the low-frequency filter are multiplied by imaginary counts from the output of the differentiating filter, and imaginary counts from the output of the low-frequency filter are multiplied by real counts from the output of the differentiating filter, the multiplication results are subtracted, they are divided by the smoothed signal module.

EFFECT: demodulation method allows to perform demodulation of frequency-modulated signals at significantly smaller ratios signal/noise, and also to reduce the necessary computing productivity of the digital demodulator.

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