METHOD AND DEVICE FOR ASSESSMENT OF CARRIER FREQUENCY Russian patent published in 1997 - IPC

FIELD: instruments. SUBSTANCE: method involves sampling input signal, calculation of spectral power density constituents using Fourier transform, calculation of carrier frequency, detection of spectral constituent $$$ with maximal amplitude of power in region of maximal concentration of spectral power density, filtration of spectral constituents using step $$$ in frequency range from $$$, calculation of first and second derivatives of spectral constituents in range $$$ in order to achieve first and second derivatives $$$ and $$$ for function of spectral power density, subtraction of $$$ from given threshold $$$, detection carrier frequency $$$ at $$$, calculation of refined value of carrier frequency $$$ at $$$ using equation $$$. Said sequence of operations starting from subtraction of function $$$ from given threshold $$$ is repeated. Corresponding device has analog-to- digital converter 1, first memory unit 2, unit 3 which performs Fourier transform and detects spectral power density, filters unit 4, second memory unit 5, control unit 6, frequency detection unit 7, NOR gates 8 and 9, first counter 10, initial setting unit 11, multiplication unit 12, counter 13, generator 14, frequency adjustment unit 15. EFFECT: increased precision of assessment. 16 cl, 24 dwg