FIELD: radio engineering.
SUBSTANCE: invention relates to radio engineering and can be used in communication systems. Method comprises generating a signal with frequency shift modulation (FSK), setting frequency values of signals such that the value of the difference of any pair of frequencies does not exceed a frequency value, for which the difference between the amplitude-frequency characteristic (AFC) of the low-pass filter (LPF) and the band-pass filter (BPF) becomes less than a certain value. After multiplication of signal and interference to reference signals, sine and cosine components, in each of parallel lines the resultant signal is branched into two identical components. First component is filtered by LPF, while the second component is filtered by BPF. Filter bands are matched with signal band. Signals passed LPF and BPF are subtracted from each other. Obtained signals are converted into digital form. Quadrature values are used to determine the spectral density (SD) for each subcarrier, which is proportional to the amplitude of the signals. Find SD with maximum value and threshold value by multiplying this value SD by a certain coefficient. Results of comparison of the SD values with the threshold make a conclusion on the presence of a signal with a corresponding frequency.
EFFECT: high noise-immunity of communication means.
1 cl, 2 dwg
