S.I. Korshakovsky

The reception of radio signals in the presence of high interference is one of the pressing problems of the up-to-date radio communications engineering. In this paper the author suggests a new method for detecting radio waves beyond the sensitivity threshold of a traditional radio receiving device, which implies the formation of two similar input channels with the resonant circuits and creation of attenuating transient processes within them by way of shock excitation of the circuits with fixed envelopes of these processes. When a useful signal is applied, resonant modes of forced oscillations with a forced phase shift equal to are formed in the circuits. The interrelation between the maximum divergence of these envelopes and the parameters of an unknown signal when the latter is acting upon a dynamic oscillatory system in antiphase is established. This interrelation has been used as a basis for identifying new properties of resonant oscillatory systems allowing to detect a useful signal which can be below the sensitivity level of traditional means of its detection. When an initial phase of the signal is unknown, the setting of phases in the formed channels is made by sequentially changing them with opposite signs, and with the attainment of a maximum divergence between signal envelopes, the attainment of a phase shift in these modes, equal to is identified. Besides, the use of the signal subtraction process enables a twofold increase in the sensitivity of the device as compared with the usual operating mode. The evaluation of the precision of implementation of the proposed algorithm is made. The relative quantity of error with the optimum selection of the relevant parameters may be less than 1%. The duration of the shaping of an intelligence signal with allowance for the operating speed of the up-to-date computing facilities can range from several unities to ten periods of signal frequency, depending on the precision and reliability of its reproduction. When real-time implementation of this process is impossible, it is helpful to make use of a preliminary recording of signals. The results of investigations carried out by the author can be used for solving applied problems in various areas of science and engineering: in designing high-tech measuring units and systems, for ensuring reliable radio communications under extreme conditions, and for solving other problems.