# A method for identifying radio

The invention relates to electrical engineering and can be used in the stations and systems monitoring. The technical result is to provide for the identification of the radio emission in significant conditions of a priori uncertainty about the parameters of the signals, noise intensity, including, when the difference of the coefficients of the transmission channel, to provide a specified level of probability of correct identification, for example to 0.9, and the division of radiation sources with a probability not less than 0.8 when the difference of the directions of the radiation sources 2 to 8° to the signal-to-noise ratio of at least 10. A way of identifying includes radio reception radio with antenna system consisting of identical antennas and multi-channel receiving device, the measurement for each of the possible combinations of pairs of antennas of complex amplitudes of signals with getting their squares and cross pieces, with an additional average of the squared modules of the amplitude on the totality of combinations of pairs of antennas and radio R_{1}define modules mutual works amplitudes and average them together combinations of pairs of antennas and radio R_{2}mutual works complex AEM modules which, in turn, averages over the set of combinations of pairs of antennas P_{3}and according to the results of averaging determine crucial statistics as the ratio of the differences of the average valueswhich is compared with the threshold established by the criterion of Neyman-Pearson, based on a given probability of correct identification and the number of combinations of pairs of antennas. 1 C.p. f-crystals, 4 Il.

The invention relates to electrical engineering and can be used in the stations and systems monitoring.

The need for identification of the radio emission, i.e. the establishment of their belonging to one or different sources, arises in many practical applications. For example, when receiving and direction finding of radio signals from transmitters to the stepwise change of frequency, multi-frequency signals, in particular signals of multi-channel radio frequency or temporary channelizing, when executed in the receiving channels of the Fourier transform, inevitably causing the binning of the spectra of the signals when you need their subsequent Union. Objective identification in these tasks is the direction to the radiation source. what tell bearings identifiable sources is faced with difficult or not solvable problem and informed choice of the threshold comparison (identification).

So there is a method of spatial identification signals, including coherent reception and registration of signals from multiple transmitters bases formed within the grid antennas, the measurement using the Fourier transform, the complex amplitude of the signals from each antenna and squares of its modules, the conversion of the aggregate of complex amplitudes using two-dimensional spatial Fourier transform in the complex angular range, the maximum of the module of which is determined by the azimuth and elevation bearings on identifiable sources, comparing them make a decision about the ownership of the radiation to one or more transmitters [RF patent №2151406, G 01 S 5/04, 5/14, N 04 17/00, 1999].

This method is the lack of information about the measurement accuracy of the bearings, for example, when the unknown signal amplitude or intensity of the noise has a low reliability of the identification. Fundamentally possible orientation on performance accuracy, but they are not always known to vary over the frequency range depends on the radio propagation conditions. All this leads to instability and negarantirovannym quality of decisions. Furthermore, the reduced sensitive to the necessity of performing a large volume of transactions, by definition, bearings identifiable sources (the conversion of the aggregate of complex amplitudes using two-dimensional spatial Fourier transform in the complex angular range, obtaining and maximizing its module).

The closest in technical essence and the achieved result to the offer (the prototype) is a way of identifying sources of radio emission, including the reception of the radio using the antenna system consisting of identical antennas and multi-channel receiver, dimension (using the Fourier transform) for each of the possible combinations of pairs of antennas of complex amplitudes of signals with getting their squares, mutual works and arguments of mutual works (phase difference), the comparison phase difference signals identifiable sources, taken on the same pair of antennas, the results of which decide to set radiation to the same or different sources of radio emission [application for invention No. 2002123675 from 06.09.2002,, CL G 01 R 27/10].

This method does not require determining the bearings of the identifiable sources, however, also has low reliability of the identification signals in the absence of information about the measurement accuracy, in this case, the phase difference between the signals, in particular when the unknown signal parameters and noise. This leads to instability and negarantirovannym quality of decisions. Medium, not having the correct statistical decision [Lehmann E. testing of statistical hypotheses, Meters, Science, S. 191, 1979].

The objective of the invention is to increase the reliability of identification of the radio emission in the conditions of a priori uncertainty about the direction of arrival of the signals, their parameters (amplitudes, phases), the intensity of noise in the receiving channels.

This is achieved by the fact that in the known method of identification of material, which consists in the reception of the radio using the antenna system consisting of identical antennas and multi-channel receiving device, the measurement for each of the possible combinations of pairs of antennas of complex amplitudes of signals with getting their squares and cross pieces, optional:

the squared modules of the average amplitude for the totality of combinations of pairs of antennas and radio P_{1};

identify the modules mutual works amplitudes and average them together combinations of pairs of antennas and radio P_{2};

mutual works complex amplitudes of the signals received on the same pair of antennas, average collectively, the radio emission with the definition of modules, which, in turn, averages over the set of combinations of pairs of antennas P_{3}:

which is compared with the threshold established by the criterion of Neyman-Pearson, based on a given probability of correct identification and the number of combinations of pairs of antennas.

Moreover, the averaging of the squared modules of the signal amplitude, in the case of the use of dual-channel receiver, alternately connected to different pairs of antennas, when the difference of the gain channels of the receiving device to perform the initial averaging the squared modules of the amplitude of the signals received by the different channels dual-channel receiver for the totality of pairs of antennas and radio emission with subsequent determination of their geometric mean.

Comparative analysis of the claimed solution with the prototype shows that the proposed method differs from the known presence of, first, new actions on signal averaging of the squared modules of the amplitude in particular with the definition of geometric mean average of the squared modules of the signals in the receiving channels; receiving modules mutual work of the amplitudes of the signals and their average; average mutual works amplitudes of the signals from the receiving module and then averaged; the conversion of the results is of textbooks: averaging over the set of combinations of pairs of antennas and radio; the threshold may be set based on a given probability of correct identification and the number of combinations of pairs of antennas.

The study of other known technical solutions in the field of equipment specified set of features that distinguish the invention from the prototype, was not identified.

The results of the statistical synthesis under uncertainty about the phase, the amplitude of the signals of the noise variance, the direction of radiation sources, the complex coefficients of the transmission channel of the receiving device to indicate that in addition to obtain sufficient statistics in the form of squares of modules of the amplitude and mutual works complex amplitudes of the signals (prototype) significant transactions are nonlinear transformation and specific averaging, in particular, changing the execution sequence of linear and nonlinear operations: averaging modules mutual works complex amplitudes and receiving module average mutual works; definition of geometric mean averaged squared modules of the amplitude of the signals in the receiving channels; carrying out the averaging over the set of radio emission and combinations of pairs of antennas.

The crucial statistic, defined as the ratio of the differences of financial p is the number of parameters, conversely depends on the parameters of the signals and noise during the reception of radiation of different transmitters. The physical basis of the availability of optimal statistical decisions is the constancy of the amplitude and phase relationships between the signals accepted by each pair of antennas, when one radiation source and the difference of these ratios otherwise. The invariance of the crucial statistics to parameters of signals and noise due to obtaining specific relationship in which unknown parameters are mutually compensated.

It is the use of the constancy of the amplitude-phase relationships between the signals and the compensatory abilities of the division operation (relationship) in accordance with the proposed new actions on signal and the conditions of their implementation, allows for identification of the radio emission with uncertainty about the phase, the amplitude of the signals of the noise variance, the direction of radiation sources, the complex coefficients of the transmission channel to the receiver.

In Fig.1 shows a structural diagram of a device that implements the proposed method, Fig.2 - histograms of the distribution of crucial statistics at the ratio of signal amplitude to the mean square value of the noise (from the m 50 (solid line) and equal to 3 (dotted line) of Fig.4 - identification.

A device that implements the proposed method contains array antenna 1.0-1.N-1, the antenna switch 2, dual-channel receiver 3, the digital circuit quadrature components 4.1, 4.2, multipliers complex numbers 5.1-5.3, accumulate adders 6.1-6.4, memory cells 7.1-7.3, adders 8.1-8.4, the shift register 9, the device module definition 10.1, 10.2, multiplier 11, the device taking the square root of 12, myCitadel 13.1, 13.2, the divider 14, the threshold element 15.

The outputs of the antennas 1.0-1.N-1 is connected to the input of the antenna switch 2, and two outputs connected to the inputs of the receiver 3. Digital circuit quadrature components 4.1 (4.2), the multipliers of complex numbers 5.1 (5.3), accumulate adders 6.1 (6.3), memory cells 7.1 (7.3), the adders 8.1 (8.3) are connected in series. The inputs of the digital circuit formation 4.1 and 4.2 respectively connected to the outputs of the first and second channels of the receiver 3. The multiplier for complex numbers 5.2, the device module definition 10.2, accumulating adder 6.2 memory cell 7.2, the adder 8.2, myCitadel 13.2, the divider 14 are connected in series. The shift register 9, the adder 8.4, the device podkluchen to the second input of the multiplier for complex numbers 5.1 (5.3) and the first (second) input of the multiplier for complex numbers 5.2, the output of which is connected to the input of the shift register 9 and the second input of adder 8.4. The output of the adder 8.1 through the multiplier 11, the device taking the square root of 12, myCitadel 13.1, the second input of the divider 14 is connected to a threshold element 15 whose output is the output device. The output of the accumulating adder 6.4 connected to the second inputs of vychitala 13.1, 13.2. The adder 8.3 output connected to a second input of the multiplier 11. The outputs of adders 6.1, 6.2, 6.3, respectively connected to the second inputs of adders 8.1, 8.2, 8.3.

Array antenna 1.0, 1.1,... ,(N-1) antenna system are identical, their number is not less than two, placed on the circumference at equal mutual destruction. One of the antennas is oriented from the center of the circle to the North and has the number 0. The numbering of other antennas clockwise with increasing numbers. The antenna switch 2 switches of the pairs of antennas in the sliding mode of the N positions in two directions in sequence numbers of antennas: 0-1, 1-2,... (N-1)-0. The total number of switching cycles (combinations of pairs of antennas) in this embodiment is equal to the number of antennas. The loop connecting one pair of antennas continues over time, the Receiver 2-channel type channel setup on the frequency of PR is uadrature components 4.1, 4.2 have a time constant equal to T, which is chosen from the condition T>1/2F. Scheme 4.1, 4.2 can be performed according to the variant shown in [Poberezhskiy K. C. Digital receiving device. M, Radio and communications, 1987, S. 67-68, Fig.3.14]. The shift register 9 has a number of digits equal to the number of switching cycles of the pairs of antennas N2. The threshold value in the element 15 is fixed, is set regardless of the noise intensity, and other parameters based on a specified level of correct identification and the number of cycles of switching antennas n

The principle of operation of the device is as follows.

Radio transmitters accept using antennas 1.0-1.(N-1) and serially connected pairs of antennas via a switch 2 receiver 3. During each switching cycle schemes quadrature components 4.1, 4.2 measured complex amplitude of a signal corresponding pair of antennas:

where_{r,l,n}- output voltage l-th (l=1, 2) receiver channel, the n-th (n=0,1,... ,N-1) switching cycle for the r-th radio emission (r=1, 2);

f_{0}the frequency of the output signal of the receiver.

Due to the independence of the noise at the input of the receiver channels is the distribution law of the form:

where- integrated signal amplitude r-th radio emission in the n-th switching cycle in the absence of noise in the receiving channels;

^{2}the noise variance at the input of the receiver channels in the band F;

- the complex transmission coefficient of the second channel, normalized relative to the first;

the pattern of the n-th antenna;

_{r}- the direction (bearing) on the r-th emitter;

- the operation of addition modulo n

Upon completion of the next interval (n+1) T the measured values of the complex amplitude (1) serves for subsequent processing. Being processed is determined by the results of the statistical synthesis based on the maximization of the likelihood function (2) for the unknown parameters: the amplitude, the phase of the signals of the noise variance, the direction of radiation sources, the complex coefficients of the transmission channel to the receiver.

Processing includes operations primarily obtain sufficient statistics (prototype) formed in the multipliers of complex numbers 5.1 (1=1) and 5.3 (1=2), the squared modules of the amplitude:

where- sign complex conjugation.

The obtained values of the sufficient statistics, as income average in accumulating the adders:

squares modules directly in blocks 6.1 and 6.3, forming after N cycles switching antennas intermediate results in the form of average signal power at the receiving channels:

where r=1,

and mutual work in the block 6.2 - after determining module in the device 10.2:

In addition, the value of works (4) memorize the shift register 9, and the intermediate results (5), (6) - in memory cells 7.1-7.3.

Upon completion of the full cycle of processing of the first radio-frequency radiation (r=1) produce similar processing for the second identifiable radiation (r=2). When the receiver 2 may be required to adjust to a new frequency or stay on a previously installed. The feature of the second half of the identification process consists in the following. First, the values of mutual worksnot only consistently recorded in the shift register 9, and summed in the adder 8.4 output values corresponding to the previously adopted from the first and the spine of the radio emission in the block 10.1 and average them together pairs of antennas in nakaplivaya the adder 6.4:

Secondly, upon completion of the full cycle switch antennas when receiving the second radio r=2, the results of averaging obtained for the first radiation r=1 and stored in cells 7.1.-7.3, average collectively, the radio emission by summing the adders 8.1-8.3.

At the output of adder 8.2 formed value:

From the results of averaging the received adders 8.1, 8.3 after multiplication in the block 11 and taking the square root of the device 12, is formed geometric mean of the squares of the amplitudes of:

If the receiving channels are identical, the operation (9) is replaced by the arithmetic mean averaged, for which the multiplier 11 is replaced by an adder, and the device 12 is a divider by two.

At the final stage of processing by performing a subtraction P_{2}-R_{3}in block 13.2 and R_{1}-R_{3}in block 13.1 further divided in the divider 14 constitute sufficient statistics:

which element 15 is compared with the threshold.

The decision about the ownership of the two radiation sources take the threshold to be exceeded. Otherwise, register one radiation source.

Further funkcja (in blocks 7.1-7.3, 9) against which to execute the subsequent identification or there is a complete loop with the accumulation of information about a new pair of electromagnetic radiation.

For identification of the radio simultaneously on multiple frequencies scheme 4.1, 4.2 are replaced by the processor fast Fourier transform, as is done in the prototype, with parallelization further described operations of the signal processing. Paralleling the operations described above signal processing is performed for the application receiving device with a large two channels.

The threshold value sets a fixed criterion of Neyman-Pearson based on a given probability of correct identification:

where W(Z) is the probability density of the crucial statistics in the presence of input radiation to the same source.

In accordance with results of analysis and modeling, statistics is crucial-distribution:

where G (.) is the gamma function;

=N/2;=N-0.5 to when non-identical channels of reception and=(N-1)/2;=N-1 - when using priemnik number N of cycles of switching antennas (pairs of antennas) and probability P of correct identification, consequently, the threshold identification depends only on these parameters, which simplifies the process of its practical calculation and setup.

If the input device of the radiation from different transmitters crucial statistics is determined by a large number of factors: the configuration of the antenna system, the order of switching of the antennas, the signal-to-noise ratios of the transmission receivers, trends in the sources.

In Fig.2 shows an example of the histogram w(Z) distribution decisive statistics for the described devices: solid line to identify a single source, dotted line - the reception signals of two sources. The number of samples upon receipt of the histogram is set to 8000, the quantization Z uniform increments of 0.01. Set the following parameters: N=9;=1.2,_{1}=0;_{2}^{*}_{}=10the ratio of the radius R to the length ofwave radiation R/=1, the ratio of signal amplitude to the mean square value of noise (signal-to-noise ratio) is 10.

It is evident from Fig.2, shows significant statistical differences is placed in the threshold element 15.

In Fig.3 shows the histogram of the crucial statistics, provided that:_{1}=_{2}=0,or =1.5, R/=1 and the signal-to-noise ratio equal to 50 (solid line) and 3 (dashed line). The above histograms are of marginal statistical differences, which confirms the position on the invariance of the crucial statistics for these parameters: phase, amplitude signals of the noise variance, the direction of radiation sources, the complex coefficients of the transmission channel to the receiving device, and allows you to stabilize the level of probability of correct identification.

The effectiveness of the invention is expressed in providing identification of the radio emission in significant conditions of a priori uncertainty about the direction of arrival of the signals, their parameters (amplitudes, phases), the intensity of noise in the receiving channels, including the difference of the coefficients of the transmission channel. The probability of correct separation of the radiation of the proposed method is determined by the expression similar to (11):

where W(Z) is the probability density of the crucial statistics in the presence of input rejected the re sources from the direction to the second source D(_{2}), provided the proposed method with N=9, k_{2}=1.1 and typical operating conditions known direction finders of signal to noise in each receive channel is equal to 10, obtained by the simulation results shown in Fig.3. The threshold value is set based on the parameters specified in the formula (12) option for non-identical channels: From=0,518 for R=0,90 and C=0,661 for R=0,99. The presented results show that when the probability of correct identification is not less than 0.9 enables effective separation of radiation sources (with probability not less than 0.8) when the difference of directions to sources of radiation from 2 to 8and the change in relative base R/from 3 to 1.

Claims

1. The method of identification of material, which consists in the reception of the radio using the antenna system consisting of identical antennas and multi-channel receiving device, the measurement for each of the possible combinations of pairs of antennas of complex amplitudes of signals with getting their squares and cross pieces, characterized in that it further average the squared modules of the amplitude on the totality of combinations of pairs of the Academy of Sciences of the particular combinations of pairs of antennas and radio R_{2}mutual works complex amplitudes of the signals received on the same pair of antennas, average collectively, the radio emission with the definition of modules, which, in turn, averages over the set of combinations of pairs of antennas P_{3}and according to the results of averaging determine crucial statistics as the ratio of the differences of the average values

which is compared with the threshold established by the criterion of Neyman-Pearson, based on a given probability of correct identification and the number of combinations of pairs of antennas.

2. The method according to p. 1, characterized in that the averaging of the squared modules of the signal amplitude, in the case of the use of dual-channel receiver, alternately connected to different pairs of antennas, when the difference of the gain channels of the receiving device to perform the initial averaging the squared modules of the amplitude of the signals received by the different channels dual-channel receiver for the totality of pairs of antennas and radio emission with subsequent determination of their geometric mean.

**Same patents:**

FIELD: detection of emergency radio buoys.

SUBSTANCE: system has two emergency radio buoys, satellite and information receipt station. Satellite has four antennae, three receipt devices, two memory devices and transmitter with antenna. information receipt station has antenna, receiver, two information processing devices, device for connecting to communication networks, control device and communication device of special rescue organizations. Third receipt device of satellite has five receipt antennae, seven mixers, six amplifiers of first intermediate frequency, two heterodynes, second intermediate frequency amplifier, block for detecting phase-manipulated signal, phase doubling block, two means for measuring spectrum width, comparison block, threshold block, delay line, two keys, phase-manipulated signal demodulator, ten multipliers, five narrow-band filters, lower frequency filter, four phase detector, five adders, four band filters, three phase inverters, two phase rotators for 90° and amplitude detector.

EFFECT: higher precision, higher interference resistance.

9 dwg

FIELD: radio communications.

SUBSTANCE: method includes, prior for each receipt station, which received radio signal with preset quality, on basis of calculated minimal normal values of total errors of phase difference of all couples of emitters in all hypothetical directions in range from 0 to 360° bearings to radio radiation source are calculated, then average value of coordinates of position of radio radiation is calculated from all points of intersection of bearing lines, after which procedure calculated coordinates are calculated using search iteration procedure of fastest descent.

EFFECT: higher precision.

3 cl, 10 dwg

FIELD: radio communications.

SUBSTANCE: at preparatory stage method includes processes for determining amount of elementary snap zones, calculation for central and R peripheral bearing points with known coordinates of values of standard primary space-information parameters relatively to coordinates of position of centers of each elementary snap zone. At operation stage method includes processes of receipt of radio emission sources signals by group of R > 1 interconnected peripheral and central bearing points, measuring primary space-information parameters at outputs of antenna elements, while primary space-information parameters, measured by peripheral bearing points are sent to central bearing point, calculations for each elementary snap zone of difference between standard and measured primary space-information parameters, selection from produced values of minimal value, and coordinates of position of center of elementary snap zone are taken as coordinates of position of detected radio emission source. As primary space-information parameters values of differences of signals phases of all possible pairs of combinations of antenna elements within effect of each bearing point. Device at central bearing point additionally has adder, memory device, decision taking block and R + 1 analysis track.

EFFECT: higher precision.

2 cl, 35 dwg

FIELD: radio engineering.

SUBSTANCE: method can be used for detection and finding of on-ground radio-frequency radiation sources. Method is based upon receiving of radio-frequency radiation in N≥3 points being distant from each other is space, transmission of data to central point, determination of R_{n}(x,y) distance from any point of (x,y) space to any n=1,2,...Nth point of receiving of data, measurement of efficient values f voltage of received radio signals U_{n}, transmission of the signals to central point where they are subject to transformation to spatial indeterminate function F(x,y). Availability of radiation and position of source are found from location and value of maximum of the function. Value and position of maximum of spatial indetermination are evaluated in neighborhood of point having coordinates to be equal to weighted average coordinates of reception points with weights being equal to measured efficient values of voltage of received radio signals raised to 4/p power. P parameter is determined while taking dependence of strength of source field into account on distance with standard value being equal to 1 or 2.

EFFECT: improved precision; increased efficiency; stabilization of false alarm level.

4 dwg

FIELD: radio engineering, in particular, radio bearing detection, possible use in systems for determining position of radio emission sources.

SUBSTANCE: in radio bearing indicator for determining two-dimensional bearing, containing ring-shaped equal-distanced antenna array with even N number of antennas, N-channel digital radio receiver, N-channel device for measuring complex amplitude, N-input buffer memorizing device, multiplier of complex numbers, clock generator, device for determining phases difference, multi-scale device for measuring phase influx and block for determining radio waves incoming angle, additionally included are pulses generator and controllable accumulating adder.

EFFECT: increased bearing detection speed.

3 dwg

FIELD: radio engineering, possible use for determining position of radio radiation sources in decametric range when using one receiving station.

SUBSTANCE: increased precision of position detection is achieved based on additional information, received as a result of division of beams of multi-beam field of received signal and modeling the process of radio-waves expansion in three-dimensional non-homogeneous ionosphere, thus making it possible to correct deviations of beam trajectories of signal by distance and by direction, considering inclinations of reflective layer of ionosphere, and also to remove ambiguousness of one-positional coordinates measuring by comparing trajectories of selected beams.

EFFECT: increased precision of one-positional determining of position of decametric transmitters.

2 dwg

FIELD: radio engineering, possible use for determining position of objects using radiations of their decametric transmitters with use of two or more receiving stations (range and direction finders).

SUBSTANCE: method is based on using additional information about rules of ionosphere distribution of decametric signals. This information is considered at each receiving station when determining assumed coordinates of objects by one-positional method with use of ionosphere model. In central calculator, connected to all stations, by comparing results of physically different methods of estimation of spatial coordinates (one-positional and multi-positional) indeterminacy of unification of measurement results is removed and position of objects is determined unambiguously with use of two or more stations.

EFFECT: increased precision of determining position of a set of one-typed decametric transmitters by wider class of signals, including complex signals with low spectral density of power.

6 dwg

FIELD: radio engineering, possible use in passive radio control systems for detecting and determining parameters of a set of transmitters with leap-like frequency alternation, simultaneously present in current receipt frequencies band.

SUBSTANCE: in accordance to method, additional signs are used for identification of signals with leap-like frequency autocorrelation function and selective functions of durations distribution and value of frequency leaps of elements of signal frequency-time matrix, preliminarily selected from input flow of signals with use of spatial mutual correlation connections between separate frequency-time signal components.

EFFECT: increased efficiency of detection of determining of parameters frequency-time matrix, describing rule of leap-like frequency alternation; average signal energy; most likely value of durations of separate radiations; speed of leap-like frequency alternation, azimuth and elevation of transmitter.

6 dwg

FIELD: passive radiolocation.

SUBSTANCE: in the known method for determining coordinates of source on basis of time difference of arrival of signals, signals are detected additionally, signal/noise ratio in which is maximal and large weight coefficients are assigned to them, to other signals appropriately lesser weight coefficients are assigned.

EFFECT: increased probability of detection and increased precision of determining object coordinates.

7 dwg, 1 program

FIELD: measuring equipment, possible use in acoustics and radio-engineering for reproducing images and determining, with increased resolution, azimuth and local angle directions towards sources of waves of various nature: resilient waves in different substances, in particular, sound waves, waves on surface of liquid and electromagnetic waves.

SUBSTANCE: method includes using nonlinear pseudo-request algorithm, providing optimization of operations of nonlinear processing of signals at each iteration of radio image restoration process (complex angular spectrum) without using normalization parameter.

EFFECT: increased direction-finding efficiency of closely located sources of radiation of coherent signals of waves of various natures.

2 dwg