K.Yu. Gavrilov1, R.Yu. Kozlov2

1,2 Research and Production Center Radiolocation Systems Development (Moscow, Russia)

1 gvrk61@mail.ru; 2 Alain.Delon1993@yandex.ru

The problem of detecting people in rooms with radar sensing through a wall is considered. It is assumed that an ultra-wideband stepped-frequency continuous-wave signal (SFCW) is used to provide high range resolution. Traditional processing of that signal is consists of quadrature phase detection, sampling and calculation of the discrete Fourier transform (DFT).

A new method using the normalization of complex samples by their own absolute values is proposed for processing the SFCW signal. With such processing, parasitic amplitude modulation of the SFCW signal is excluded, due to the presence of interference and non uniformly amplitude-frequency characteristics of the transmitting and receiving circuits of the radar. The description of the algorithm for the formation of the range profile when detecting people in the radars of sensing rooms through the wall is given.

The effectiveness of detecting people considered as mobile or fluctuating targets depends on the ability to detect changes in slow-time complex samples corresponding to neighboring probing periods. Algorithms for detecting signals of mobile targets based on the calculation of the interperiod difference or variance of samples over several periods (frames) are described. For each of these algorithms, it is possible to use the proposed processing of SFCW signals, which leads to an increase of the resulting signal-to-noise ratio.

The results of computer modeling and field experiments are presented, confirming the effectiveness of the proposed method and showing the possibility of increasing the value of the signal-to-noise ratio by 1...5 dB compared with traditional processing of SFCW signal without normalization of samples.

Gavrilov K.Yu., Kozlov R.Yu. SFCW signal processing method when detecting people in radars sensing rooms through a wall.
Radiotekhnika. 2022. V. 86. № 4. P. 117−131. DOI: https://doi.org/10.18127/j00338486-202204-15 (In Russian)

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