Yu.E. Korchagin1, K.D. Titov2, E.E. Golovatskaya3

1-3 Voronezh State University (Voronezh, Russia)

2 Military Educational and Scientific Center of the Air Force «N.E. Zhukovsky and Yu.A. Gagarin Air Force Academy» (Voronezh, Russia)

Trends in the development of existing communication and data transmission systems largely consist in expanding the spectrum and increasing the level of modulation of signals used to transmit information. Increasing the efficiency of information transmission and processing with a steady increase in the requirements for the stealth and noise immunity of radio lines is based on the use of ultra-wideband (UWB) signals. Among the many UWB signals, a separate class is distinguished - UWB quasi-radio signals (QRS), the structure of which is similar to narrowband radio signals, but the condition of relative narrowband is not fulfilled for them.

Currently, communication systems using narrow-band signals as a carrier oscillation are widespread. When developing ultra-wideband radio communication systems, it is necessary to investigate the effect of narrowband interference on the characteristics of the synthesized detector. Modern information systems for various purposes can operate in a complex interference environment, when several sources with narrowband signals operate in the useful signal band, which have a negative impact on the ultra-wideband communication system. Aggregates of narrow-band interfering signals will be called discrete-covering jams (DCJ).

In this regard, the purpose of the work is to synthesize and analyze algorithms for detecting UWB QRS with unknown amplitude, initial phase and duration observed with white Gaussian noise and DCJ. The influence of interference on the effectiveness of the detector has been estimated. The dependences of the detection characteristics on various parameters of the useful and interfering signals are obtained and the conditions under which the strongest destructive effect is achieved are determined.

It is shown that an increase in the elements of pulses in DCJ does not lead to a significant deterioration in the effectiveness of detecting UWB QRS. The strongest influence is the duty factor of interference and the degree of consistency of one of the narrowband interferences with the carrier frequency of the useful signal. As narrowband interference moves away from the carrier frequency of the UWB QRS, the degree of exposure is significantly reduced, regardless of their width, energy, phase disorder and duty factor. It is determined that a significant increase in the interference energy at values of the interference/signal voltage ratio above two does not lead to a significant deterioration in the efficiency of the UWB QRS detector, and is largely determined by the interference/signal ratio of the central element in the DCJ. However, it should be borne in mind that exposure to heavy-duty interference sources can lead to "locking" of the receiver or its functional damage.

The maximum value of the missing probability is reached when the narrowband interference is in antiphase with the useful signal, and the minimum value when the useful and interfering signals are inphase. The dependence of the missing probability on the initial phase disoder has a significant slope level, indicating that a small disorder in the initial phase can lead to a significant improvement or deterioration in the probability of detection.

It is established that the presence of interference in the received realization that has a mismatch in parameters with the useful signal can lead to the impossibility of processing the useful signal with a given reliability. Taking into account the recommendations formulated will improve the efficiency of the detector operating in a complex interference environment, destabilizing information and technical influences or attempts to unauthorized access to information.

Korchagin Yu.E., Titov K.D., Golovatskaya E.E. Detection of ultra-wideband quasi-radio signal in the conditions of the influence of discrete-covering jams. Radiotekhnika. 2022. V. 86. № 8. P. 70−83. DOI: https://doi.org/10.18127/j00338486-202208-08 (In Russian)

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