When using quadrature signals in radio channels, flat and selective fading, multipath radio reception, intersymbol interference, and jitter occur. In addition to the need to accurately estimate the value of the phase difference at the current and previous clock intervals, a critical factor in receiving and demodulating such signals is the accuracy of measuring the amplitude of their samples. When demodulating such signals, an approach is possible, the basis of which is to measure the values of individual signal samples at discrete time points with higher accuracy than in existing electronic devices. Such an approach can be implemented by an optoelectronic device in which a coherent luminous flux is formed, the parameters of which are modulated by a voltage proportional to the readings of the received radio signal. Using a modulated light flux, an interferogram is formed, the parameters of which are directly related to the parameters of this light flux and accordingly to the parameters of the received radio signal. This makes it possible, by increasing the accuracy of estimating radio signal samples, to increase the base of the alphabet used for code manipulation, the efficiency of using the allocated frequency band for transmitting information and reduce the probability of a bit error. The article presents a mathematical model for converting the parameters of the received radio signal into the parameters of the generated interferogram. By mathematical modeling the accuracy characteristics of an optoelectronic device for measuring radio signal samples were evaluated. The results of mathematical modeling illustrating the relationship of the parameters of the optical elements of the device with the accuracy of estimates of the radio signal counts are presented. The practical significance of the proposed optoelectronic device can be used as an independent device for analog-to-digital conversion of radio signals, as well as part of demodulators for QAM and OFDM signals in networks and communication systems of 5G and the next generations.
