METHOD OF ESTIMATING SIGNAL-TO-NOISE RATIO AT INPUT OF RECEIVING DEVICE FOR RADIO SIGNAL WITH DIGITAL AMPLITUDE MODULATION Russian patent published in 2019 - IPC G01R29/26 

FIELD: measurement.

SUBSTANCE: invention relates to measurement of electrical quantities. Signal-to-noise ratio is calculated using a second-order partial differential equation of the form

u₁(t, x) is a function of external disturbances; u₂(t, x) is unknown function, propagation voltage equivalent; q₁,q₂,q₃,q₄,q₅ are coefficients taking into account environment properties; m is coefficient index of partial differential equation; Im q_m is the imaginary part of the m-th coefficient; t is time; x is coordinate; T is maximum value of time; L is maximum coordinate value; is the set of positive integers; is the set of real numbers; is a set of complex numbers; with boundary and initial conditions

which is solved approximately using a high-performance computing device based on Fourier's method of separating variables with a complex time basis of decomposition of the unknown function and the function of external disturbances. Model uses one useful signal s(t) and two "malicious" components: intrinsic noise of the transmitter e₁(t) and external interference e₂(t). Useful signal s(t) and the intrinsic noise of the transmitter e₁(t) is located in real part u₁(t, x) before calculating u₂(t, x). External interference e₂(t) is added at design point to real part u₂(t, x) after its production. Minimum signal-to-noise ratio at the model output is estimated on a time interval of the reference signal with a minimum amplitude level. Maximum value of the signal-to-noise ratio at the model output is evaluated on a time interval of the reference signal with a maximum amplitude level. Final signal-to-noise ratio is the minimum value at the model output.

EFFECT: technical result consists in improvement of accuracy of evaluation of signal-to-noise ratio at input of receiving device for radio signal with digital amplitude modulation.

1 cl, 8 dwg, 3 tbl