M. L. Artemov – Dr.Sc. (Eng.), Associate Professor, Temporary General Director,

JSC “Concern “Sozvezdie” (Voronezh)

E-mail: m.l.artemov@sozvezdie.su

O. V. Afanasyev – Ph.D. (Eng.), Director of Scientific and Technological Center “REW and Special Communication”, JSC “Concern “Sozvezdie” (Voronezh)

E-mail: o.v.afanasev@sozvezdie.su

M. Yu. Ilyin – Ph.D. (Eng.), Senior Research Scientist,

JSC “Concern “Sozvezdie” (Voronezh)

E-mail: miuril@rambler.ru

O. A. Serebryannikova – Engineer,

JSC “Concern “Sozvezdie” (Voronezh)

E-mail: serebryannikova.ol@yandex.ru

M. P. Slichenko – Dr.Sc. (Eng.), Head of Sector,

JSC “Concern “Sozvezdie” (Voronezh)

E-mail: m.p.slichenko@sozvezdie.su

At the solution of some problems of radio monitoring there is a necessity of detection and direction finding of several sources with close levels of accepted frequency-inseparable radio signals in the conditions of unknown noise level of receiving channels, for example, at radio monitoring of work of data transfer networks of the standard 3G, based on the technology of multiple access with code separation of channels.

In modern systems of radio monitoring for the purpose of maintenance of demanded speed of survey of an operating range of frequencies there is a restriction in possible quantity of accumulation of the covariance matrix of accepted signals. Researches showed that for small (about an one ten) quantities of accumulations the parameters of efficiency of ways of detection and direction finding of several sources of the frequency-inseparable radio signals based on calculating eigen values of a covariance matrix become worse and generally do not provide univocal conformity between quantity of eigen values of a matrix which have exceeded a threshold and quantity of sources of frequency-inseparable radio signals.

Offered in [3] way of spatially multichannel correlation detection of sources of radio signals is based on the following difference in “nature” of signal and noise components. The signal component characterises distribution of the amplitude and phase of the source radio wave field at the aperture of detection-direction finder antennas, and the noise component has no given representation as its components in various receiving channels have casual amplitudes and phases which have not been caused by falling of some radio wave with a flat wave-front that leads to low interchannel correlation [3, 4].

However low interchannel correlation also occurs in the presence of several sources with close levels of accepted signals that may lead to the dropping of signals when using a detector [3]. Thus, with reference to the specified case it is necessary to develop results of works [3, 4] and to develop a way of detection and direction finding of sources with close levels of accepted frequency-inseparable radio signals.

The work purpose is developing a way of detection and multisignal direction finding of sources with close levels of accepted frequency-inseparable radio signals in the conditions of prior uncertainty regarding to noise intensity and quantity of sources.

The offered way of adaptive two-threshold detection and multisignal direction finding of sources of frequency-inseparable radio signals assumes a multistage processing of the observed data which includes two-threshold correlation detection, noise level estimation, multichannel power detection, estimation of quantity and directions on sources in the conditions of prior uncertainty regarding to the level of accepted signals, directions of their arrival, noise level and number of sources of radio frequency radiation. The estimation of unknown noise level is carried out over spectral samples with low space correlation that allows raising the estimation accuracy and parameters of efficiency of adaptive power detection.

Implementation of the offered way in the perspective systems of radio monitoring allows to raise parameters of efficiency of radio monitoring of several sources with close levels of accepted frequency-inseparable radio signals, including, radio monitoring of work of data transfer networks of the standard 3G, with maintenance of demanded speed of survey of the operating frequencies range in the conditions of saturated electromagnetic environment.

1. Patent RU № 2204840. The method of multichannel detection and estimation of the number of radiation sources with adaptive noise power equalization in the channel. G.A. Tarasov, I.V. Kabakov, A.U. Nezvanov. Publ. 20.05.2003. (in Russian)
2. Patent RU № 2190236. The method of detecting and determining the two-dimensional bearing and frequency of radio sources. V.N. Shevchenko, G.S. Emelyanov, G.G. Vertogradov. Publ. 27.09.2002. (in Russian)
3. Patent RU № 2696022. The method of adaptive spatial multichannel detection of spectral components of radio emission source signals. M.L. Artemov, O.V. Afanasyev, E.L. Abramova, M.P. Slichenko. Publ. 30.07.2019. Bul. № 22. (in Russian)
4. Artemov M.L., Afanasyev O.V., Slichenko M.P. Detection and direction finding of sources of radio emissions within the limits of the theory of statistical radio engineering. Radioengineering. 2016. № 5. P. 4–18. (in Russian)
5. Tikhonov V.I. Statistical radio engineering. M.: Sov. radio. 1966. (in Russian)
6. Levin B.R. Theoretical foundations of statistical radio engineering. M.: Radio and communication. 1989. (in Russian)
7. Repin V.G., Tartakovsky G.P. Statistical synthesis with priori uncertainty and adaptation of information systems. M.: Sov. radio. 1977. (in Russian)
8. Artemov M.L., Slichenko M.P. The modern approach to the development of the methods of direction finding of radio waves of radio emission sources. Antennas. 2018. № 5. P. 31–37. (in Russian)
9. Slichenko M.P. Multichannel energy detector of unknown quasideterministic radio signals. Theory and technique of radio communication. 2014. № 3. P. 49–56. (in Russian)
10. Vinogradov A.D., Dmitriev I.S., Ilyin M.Yu. , Slichenko M.P. Multi-signal maximum likelihood algorithm of detecting and evaluating the directions of arrival and amplitude of field strength of plane monochromatic radio waves using a multi-channel radio direction finder with an antenna system of arbitrary configuration. Antennas. 2012. № 4. P. 55–64. (in Russian)
11. Artemov M.L., Slichenko M.P. Adaptive multi-signal algorithm of joint detection and direction finding of plane monochromatic radio waves using a multi-channel radio direction finder with an antenna system of arbitrary configuration. Antennas. 2014. № 5. P. 50–54. (in Russian)