UDC 621.396
FAST FOURIER TRANSFORM ALGORITHM OF NONEQUIDISTANT PULSES SEQUENCES
V. I. Koshelev, Dr. Sc. (Tech.), full professor, RSREU, Ryazan, Russia;
orcid.org/0000-0002-8666-8460, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
N. H. Trinh, post-graduate student of radiotechnical department of the RSREU, Ryazan, Russia;
orcid.org/0000-0002-2456-5220, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Fast Fourier transform algorithms are well developed and successfully used in applied problems of radio engineering, in particular, for the implementation of multi channel Doppler filtering in systems for radar signals primary processing. In case of non-equidistant pulse sequences, matched filtering algorithm must take into account the law of change in signal sample repetition periods, which leads to a modification of the fast Fourier transform algorithm. Fast Fourier transform algorithm for processing non-equidistant pulse sequences with two different repetition periods is known and considered in this paper. In this work, modified and combined fast Fourier transform algorithms for processing non-equidistant pulse sequences with three different repetition periods are obtained and analyzed. The aim of the work is to synthesize the structure of modified fast Fourier transform algorithm under the conditions of processing an echo signal consisting of bursts of three-stage non-equidistant pulses, as well as the optimization of its parameters using the criteria for signal-(noise + interference) ratio improvement coefficient averaged over frequency channels and the average probability of correct signal detection against the background of white Gaussian noise and narrowband noise
Key words: : multichannel Doppler filtering, non-equidistant pulse train, average probability of correct signal detection, average signal-(noise+interference) ratio improvement factor, modified and combined fast Fourier transform algorithms