RU2316899C1 - Method for creating retranslated interferences - Google Patents

Abstract

FIELD: radio engineering, possible use for disrupting normal operations of means which use broadband multi-based radio signals, by influencing them with retranslation type interferences.

SUBSTANCE: method includes realization of two-dimensional search with independent statistic of thermal noises which is synchronous in frequency of broadband radio-signals, of continuous mutual correlative and filtering processing of two processes, created as a result of searching, and recording of fact of appearance of maximal response of mutual correlative and filtering processing. On basis of aforementioned fact search is stopped and further at stopped search frequency f all broadcasting radio signals are received from visible constellation of man-made navigational Earth satellites, generating a random series of copies of mixture of received radio signals (including ones received with level below level of thermal noises of receiving route) with frequency of repeat of copies which a priori exceeds frequency of repeat of navigational signal, and generated copies of radio signal mixture are emitted simultaneously in isotropic fashion at frequency f in different points of space, introducing random shifts to value of carrier frequency of radiation f.

EFFECT: saturation of navigational or other informational channels of consumers by a stream of false messages which conceal true ones.

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Description

The invention relates to radio engineering and can be used to disrupt the normal operation (suppression, disorientation) of means that use broadband multi-base radio signals, primarily consumers of navigation space information (PNI), by exposing them to interfering electromagnetic waves - relay-type interference.

A known method of solving the problem of exposure to additional signals on the operation of information channels in space radio navigation systems (SRNS) of the second generation. A characteristic feature of the current stage of development of second generation CRNS is their integration into more complex information systems and complexes. An example is differential systems with the networks of reference (control and corrective) stations included in them, which are considered as a functional complement (PD) of the CRNS.

Systems using the principle of relaying (re-emission) of signals from navigational artificial Earth satellites are becoming a promising option for the SRNS PD [1]. This method of exposure consists in the fact that the repeater (P) receives signals from navigational artificial Earth satellites (NIEH) and their radiation with complete or partial storage of information. The signals emitted by P can be used by the consumer for navigational and temporal determinations, both along with signals received directly from the NISS, and independently of the latter. Moreover, P can play the role of a “pseudo-satellite”. The network of such Ps allows to supplement (or even to a large extent replace) in the local zone the orbital constellation of the NLHA.

The known method is presented as a principle of influence on information channels, but it provides for the composition and sequence of operations aimed at achieving a control-correcting effect that does not lead to a disorienting result.

Known [2] is a method of creating relayed interference, which consists in amplifying a received broadband signal (BSS) with a duration τ of an elementary symbol of a pseudorandom sequence (SRP), storing an implementation of duration T with subsequent repeated re-emission. After amplification of SHPS, the remembered implementation is distorted according to the law of low-frequency SRP. The duration of the elementary symbol of the low-frequency memory bandwidth and the duration of the memorized implementation are determined by the given algorithms. The distorted broadband signal is emitted with various delays.

The presented analogue method provides false signals saturation of information channels of a narrow class, limited by the task of radio communication. Organized by the analogue method, the interference does not have a target direction for a significant distortion of the “delay” parameter. A relay signal after distortion according to the law of low-frequency SRP acquires a distinguishing feature of an interfering signal, which, in principle, can be used by the suppressed party to reduce the interference efficiency by means of correlation filtering of a true message. In addition, the application of the method is limited by the need to know the basic parameters of the distorted SHPS.

In the known methods there are no operations for determining the value of the carrier frequency of the NPS, the knowledge of which is necessary for receiving, memorizing and re-radiating the implementation. When interfering with information radio systems using multi-base NPS, this definition is specific, since the level of the received signal can be significantly lower than the level of the internal thermal noise of the receiving device. In this case, conventional signal processing methods become ineffective, which necessitates the use of methods based on new principles.

Known [3] is the method used to detect pseudo-random and phase-coded (FCM) signals using binary phase codes. It is based on the principle of frequency doubling after conversion to an intermediate one. As a result of doubling the frequency, the BSS is converted to narrowband, which greatly simplifies its further processing. Further, by dividing the frequency, the double-frequency signal is restored to its original form and is used as a coherent reference signal for decoding the PCM signal. In the case of applying N-phase codes, the signal generation is performed respectively using multiplication and division by N. This method is applicable to continuous and pulsed PCM signals.

The limitation of the application of this method for the classes of processed SHPS consists in the necessity of enumerating N values (the number of phase gradations) and the impossibility of applying the method with a broadband (large base) signal organized without using PCM.

The closest in technical essence in terms of generating an interfering signal is a method [4] of electronic suppression of correlation radar stations, the purpose of which is to disrupt the operation of correlation tracking systems and / or the formation of numerous peaks in the correlation functions calculated by the correlator. Since correlation devices select signals by evaluating the phase of the signal from pulse to pulse, the implementation of the method should not violate the coherence of all relayed pulses. This is achieved by performing operations of relaying with periodic radiation of a delayed sample of the signal of the suppressed radar.

The prototype is focused on electronic suppression of radar targets, and can also be used to interfere with communication systems. However, it does not provide for the execution of operations that enable the inclusion of SRS signals in the structure of suppressed consumers.

To eliminate this drawback, it is necessary through additional operations to ensure the distortion of all navigation parameters (such as: the time delay of the signal, the phase of the carrier frequency, Doppler shift) and create conditions for the disruption of the auto tracking of navigation signals or the transition to auto tracking of interference. It is also advisable to ensure the barrage nature of the interference by the number of navigation information providers.

The objective of the proposed method for creating relayed interference is to expand the range of radio jamming objects by including consumers of space navigation information (PKNI) in it, which is achieved by performing the original processing of the received signal and generating interference.

The technical result of the invention is the saturation of navigation or other consumer information channels with a stream of false messages that mask the true. Achieving this effect is advisable, for example, when organizing the protection of ground objects from attacks by high-precision weapons of air (or sea) based type of cruise missiles. The factor of such protection will be the disorientation of the on-board electronic guidance coordinators working on signals from space radio navigation systems (SRNS).

The technical result is achieved by performing a two-dimensional, with independent statistics of thermal noise, synchronous frequency search of broadband radio signals, continuous cross-correlation and filter processing of two processes resulting from the search, fixing the fact of the appearance of the maximum response of the mutual correlation and filter processing; on this fact, the search is stopped and then, at the stopped search frequency f, all broadband radio signals from the visible constellation of navigational artificial Earth satellites are received, a random sequence of copies of the mixture of received radio signals (including those received with a level below the thermal noise level of the receiving path) is generated with a copy repetition rate, a priori exceeding the repetition frequency of the navigation signal, and radiation of the generated copies of the mixture of radio signals at a frequency f is carried out isotropically and simultaneously at various points in space, while random shifts are introduced into the value of the carrier frequency of the radiation f.

The drawing shows a diagram of a device that implements the method.

The inventive method is performed in the following sequence.

1. Carry out a two-dimensional synchronous search for signals in frequency. The two-dimensionality of the search is necessary for the processing of coherent signals masked by thermal noise with independent statistics.

2. Conduct continuous mutual correlation and filter processing of two output processes resulting from the search. Mutual correlation processing of the output processes is necessary for converting the NPS into narrowband (the operation of signal compression with a large base over the spectrum). Through filtering, the influence of the side lobes of the mutual correlation function of the matching signals, the products of the mutual correlation processing of different signals is weakened, and the frequency band of thermal noise is narrowed.

3. The fact of the appearance of the maximum peak response of the mutual correlation processing of processes is recorded. All signals emitted at the same carrier frequency by each of the simultaneously observed NEAs contribute to the response structure.

4. Correlate the current value of the search frequency with the moment the maximum peak appears. The value of the search frequency, which coincided with the moment of the appearance of the maximum response of the mutual correlation processing, is equal to the value of the carrier frequency f of the received signals.

5. Receive the set of radio signals at a frequency f, amplify it and then form a mixture of copies of the set of radio signals in the form of a random sequence with a repetition rate that is a priori higher than the repetition frequency of the navigation signal. Such a structure of the interfering signal will ensure the overload of the information channel and the barrage character of the disorder of the PNI in the range of real values of the navigation parameter contained in the signal delays.

6. The random shifts are introduced into the value of the carrier frequency f, with the help of which the normal operation of the phase-locked loop is disrupted (paralyzing the measurement of the navigation parameter on an accurate scale) for the PNI.

7. The generated interfering signal is emitted isotropically simultaneously at various spatial points.

The interference field distributed in such a way in space will ensure the invariance of the interference to the spatial position of the PNI.

A comparative analysis of the proposed method with the prototype shows that the hallmarks of the invention are:

- the implementation of a two-dimensional synchronous search for signals in frequency simultaneously with continuous mutual correlation and filter processing of two output processes resulting from the search;

- correlation of the current value of the search frequency to the moment of the appearance of the maximum response of the mutual correlation and filter processing and the perception of this value as the carrier frequency f of the received radio signals;

- the simultaneous reception at a frequency f of radio signals from the observed NHSS, including signals with levels below the level of thermal noise;

- the formation of a mixture of copies of the totality of received at the frequency f of the radio signals in the form of a random sequence of copies with a repetition rate that is a priori higher than the repetition frequency of the navigation signal;

- introduction of random shifts into the value of the carrier frequency f;

- the set of operations isotropic and simultaneous at different points in the space of radiation interference.

The listed distinguishing features presumably indicate that the claimed technical solution meets the criterion of "novelty", as it is not identified in the known technical solutions.

The features that distinguish the claimed technical solution from the prototype, do not follow explicitly from the known technical solutions and, therefore, supposedly ensure compliance with the criterion of "inventive step".

For the physical implementation of the proposed method in relation to the partial radiation of interfering signals, a device can be used, the structural diagram of which is shown in the drawing. The directions of the main functional processes in the device are indicated by arrows, and the functional elements of the device are indicated by:

1, 2, 17 - antennas;

3, 4, 13 - high frequency amplifiers (UHF);

5 - frequency synthesizer (MF);

6, 7, 11 - mixers (cm);

8 - control device (UE);

9, 10 - amplifiers of intermediate frequency (UPCH);

12 - device correlation filter processing (UKFO);

14 - a decisive device (RU);

15 - high-frequency processor-former (Pr);

16 - power amplifier (PA).

The input stream of radio signals is simultaneously received by antennas 1, 2, amplified in UHF 3, 4, converted by frequency through Cm 6, 7, the inputs of which receive the input stream of radio signals and a heterodyne signal synthesized by the midrange 5. The radio signal streams at an intermediate frequency are amplified in UPCH 9 , 10 and enter the inputs of UKFD 12 and Cm 11. The radio receiving paths 1, 3, 6, 9 and 2, 4, 7, 10 are identical in their amplitude, phase, and time characteristics. Such an identity ensures strict coherence of the signal components of the processes arriving at the inputs of UKFD 12. The absence of mutual correlation between the stochastic components of these processes due to the noise temperature of the receiving paths ensures the independence of the latter.

The synchronous search mode for the frequency of broadband radio signals is implemented by software tuning of the midrange 5; the programmable element is UU 8.

In UKFO 12, mutual correlation and filter processing of input processes resulting from synchronous search is performed. The processing response arrives at RU 14, which, according to the selected criteria, establishes the fact of detecting a broadband radio signal and generates a command by which the search is terminated and the procedure for generating interference signals at the carrier frequency f is initiated.

In Cm 11, the radio signal is restored at a frequency f using the local oscillator signal supplied to the corresponding input Cm 11 from MF 5. The frequency of the local oscillation signal used for reconstruction is randomly shifted by the programmed control unit 8. The recovered radio signals after amplification in UHF 13 are fed to input Pr 15, in which they are used to form a random sequence of copies of the mixture. The generated interference signal after amplification in the PA 16 is radiated into space by means of a transmitting antenna 17.

The combination of such devices distributed in space, in combination with isotropic radiation, creates a noise field distributed in space and, thus, realize the principle of invariance of interference effects to the random position of information consumers.

The principle of noise barrage by the number of navigation information providers is implemented by including in the mixture all navigation signals received on one carrier frequency f.

The possibility of physical implementation of each of the functional elements included in the device is not in doubt. It is only necessary to provide some explanations.

Isotropic reception implies the use of antennas 1, 2, each of which has a radiation pattern that provides the reception of radio signals from sources located in the hemisphere. Isotropy of radiation implies the use of an antenna 17 with a wide radiation pattern, the orientation of which is determined by the tactics of using devices that form an interfering field.

The correlation-filter processing device is implemented on the basis of a combination of a multiplier and an integrator according to well-known technical solutions used in correlation optimal receivers of complex signals with a large base. But here a distinctive feature is that instead of the reference signal, the output process of the symmetric search channel is used.

In the solving device 14, the decision-making procedure can be determined by the set detection statistics by threshold algorithms optimized, for example, by the Neumann-Pearson criterion.

The implementation of the high-frequency processor-former 15 can be carried out using various technologies (digital, analog). It seems appropriate, guided by the desirable preservation of the fine phase structure of the processes being processed, to use, for example, the technical solutions contained in [5].

The goal is achieved in that each consumer, as a result of interference, deals with the chaotic structure of the input information stream, in which individual signals that carry true information and a large number of signals with false information are identical in tracking parameters. The proposed sequence of actions provides the possibility of organizing the saturation of consumer information channels with a stream of false messages that mask the true ones with unknown characteristics of the latter.

Information sources

1. Vlasov IB, Pudlovsky VB Local differential subsystem of SRNS on the basis of repeaters // Proceedings of IX MHTK "Radar, Navigation, Communication", v.3 - Voronezh, 2003.

2. The method of creating relay interference // RU, patent, 2123238, cl. H04K 3/00, 1998.

3. Perunov Yu.M., Fomichev K.I., Yudin L.M. Radio-electronic suppression of information channels of weapon control systems. - M .: "Radio Engineering", - 2003. - p. 338, 339.

4. A method of creating interference based on relaying with periodic radiation of a delayed sample of the signal of the suppressed means / Leroy B. Ian Brunt. Applied ECM. Handbook of methods for electronic suppression and noise immunity of systems with radar control. EW Engineering Inc., USA, 1978, v. 1, chap. 4, section "Radio-electronic suppression of correlation systems".

5. Fiber optic device for generating copies of a high-frequency signal // RU, patent, 2089046, class. H04B 10/00, 1992.

Claims (1)

The method of creating relayed interference, which consists in amplifying the received broadband radio signal, storing and then repeatedly re-emitting it with various delays, characterized in that they perform a two-dimensional, with independent statistics of thermal noise, synchronous frequency search of the broadband radio signals with subsequent continuous mutual correlation and filter processing of the two processes, fixing the fact of the appearance of the maximum response, stop the search for this fact and then on the stopped part totet f receive all broadband radio signals from the visible constellation of navigational artificial Earth satellites, form a random sequence of copies of a mixture of received radio signals (including those with a level below the thermal noise level) with a copy repetition frequency that is a priori higher than the repetition frequency of the navigation signal, and emit generated copies of the radio signal mixture at a frequency f is isotropic and simultaneously at different points in space, while random shifts are introduced into the value of the carrier frequency of the radiation f.