D.D. Privalov1, D.P. Sedunov2

1 Omsk Scientific Center SB RAS (Institute of Radiophysics and Physical Electronics) (Omsk, Russia)
2 Omsk Scientific-Research Institute of Instrument Engineering (Omsk, Russia)
 

In connection with the increasing requirements for the data transfer rate, the tasks in terms of continuous improvement of algorithms and methods of signal generation, data transmission and processing are relevant. The information signal is negatively influenced by noise and interference in the communication channel, the Doppler effect and imperfection of the radio equipment used. Therefore, in order to ensure high-quality extraction of information from the received radio signals, their detection and subsequent synchronization must be performed in the receiving device. At the same time, it is necessary to strive to minimize the load on the digital signal processor. The purpose of this article is to study the possibility of using an algorithm for estimating the frequency of a non-modulated carrier signal for its detection.

The first part presents the algorithm of the energy detector and describes how it works. It is shown that the decision on the presence or absence of a useful signal is made on the basis of comparing the square of the received mixture with the threshold. In the second part, Kay's algorithm is considered as an algorithm for determining the frequency of an unmodulated signal carrier. Graphs of frequency estimation by Kay's algorithm in the time domain for various signal-to-noise ratios are plotted. S-curves are given that characterize the dependence of the average value of the frequency estimate on the frequency itself.

In the third part, dependences of the mean square deviation of the normalized estimate of the frequency of Kay's algorithm are constructed. The probabilities of false signal detection are calculated. Graphs of the probability of detecting a signal depending on the signal-to-noise ratio are presented. The results obtained showed that Kay's algorithm is applicable for detecting signals that use an unmodulated carrier as a pilot insert. However, as a disadvantage of this approach, it can be noted that the frequency estimation error at the output of the Kay algorithm deteriorates with increasing frequency shift.

Privalov D.D., Sedunov D.P. Investigation of the possibility of using an algorithm for estimating the frequency of a non-modulated carrier signal for its detection. Radiotekhnika. 2023. V. 87. № 3. P. 92−97. DOI: https://doi.org/10.18127/j00338486-202303-09
(In Russian)

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