RU2353050C1 - Adaptive multi-functional correlation and filtering device - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to radio measuring engineering and radio communication and may be used for radio signal parameters measuring. For this purpose, search channels by frequency and signal detection, adaptation channel by signal medium frequency and timing frequency and signal classification and precise parameters measuring channel are additionally introduced into the adaptive multi-functional correlation and filtering device based on frequency discriminator.

EFFECT: wide functional possibilities, improved interference stability and classification, reduced error of amplitude, medium and timing frequency measuring for phase-shift keyed signals.

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Description

The invention relates to radio engineering and radio communications and can be used to determine the parameters of radio signals.

One of the urgent directions in radio communications is to increase the energy secrecy of the created communications. To ensure the secrecy of the created communications, broadband signals with a low energy potential are used, including phase-shifted signals (PMS).

When conducting radio monitoring of weak FMS, it becomes necessary to detect, classify and evaluate such parameters as amplitude U _ms , clock frequency F and average frequency f _s . In addition, when building radio monitoring tools, it is necessary to ensure the efficiency of processing FMS.

In view of the above, in order to conduct effective radio monitoring of weak broadband FMS, it is necessary to develop the principles of constructing a multifunctional autocorrelation device (UIA) that functions in the absence of a priori information about the class and parameters of the received signals (U _ms , F, f _s ) with a signal / noise ratio of less than unity.

In the theory of potential noise immunity it is shown that for solving such problems the most effective are the algorithms of autocorrelation processing [1].

A device for measuring the average frequency of signals (AS USSR No. 1237985, published in OBI No. 22, 1986), containing a quadrature phase correlator, to one of the inputs of which the signal is supplied directly, and to the other through the delay line, at the outputs of the multipliers The phase correlator includes integrators, quadrators, blocks of subtraction, summation, division, functional converter and indicator.

The signs of this analogue, which coincide with the essential features of the claimed device, are a quadrature phase correlator, at the outputs of which integrators and quadrators, a functional converter and an indicator are included. The disadvantages of the analogue include: 1) a small permissible slope of the discriminatory characteristic, 2) the ability to process at a received signal level greater than the interference level, 3) limited functionality, since only one signal parameter is measured (average frequency).

There is also known a device for determining classes of radio signals (AS USSR No. 1503024, published in OBI No. 31, 1989), containing a correlation filter device, delay lines, integrators, phase detectors, multipliers, a generator, a phase shifter, subtraction and summation blocks, indicator in the form of a cathode ray tube.

The signs of this analogue, which coincides with the essential features of the claimed device, are a correlation-filter device, the outputs of which include integrators, phase detectors, a delay line, a phase shifter, multipliers, subtraction and summation blocks, an indicator. The disadvantages of the analogue include: 1) low speed, 2) the ability to process at the level of received signals greater than the level of interference, 3) limited functionality, since only the classification of signals is carried out.

Of the known devices suitable for processing weak broadband signals, the closest in technical essence is the frequency discriminator (AS USSR No. 936374, published in OBI No. 22, 1982), implemented on the basis of a correlation-filter conversion, containing two mixers, two band-pass filters, delay line, phase shifter, two phase detectors, low-pass filter, error signal extraction unit, harmonic oscillation generator, control element, stimulating signal generator, the first output of which is connected n to the input of the frequency discriminator, and a second output coupled to an input of the second phase detector; the input of the frequency detector is connected to the first input of the first mixer and to the first input of the second mixer, the second input of the first mixer is connected to the output of the delay line, the output of the first mixer is connected to the input of the first bandpass filter, and the output of the first bandpass filter is connected to the first input of the first phase detector, output the second mixer is connected to the input of the delay line, the second output of the harmonic oscillator is connected to the input of the phase shifter, the output of which is connected to the second input of the first phase detector the output of which is connected to the inputs of a low-pass filter and a second band-pass filter; the output of the low-pass filter is the output of the frequency discriminator, the output of the second bandpass filter is connected to the second input of the second phase detector, the output of which is connected to the input of the error signal isolation unit, the output of which is connected to the input of the control element, the output of which is connected to the control input of the harmonic oscillator.

All of the above essential features of the prototype coincide with the essential features of the claimed device.

In this device (prototype) [2] only the average frequency of broadband signals is evaluated. In accordance with the terminology adopted in [3], the frequency discriminator belongs to the class of specialized correlation-filtering devices.

The disadvantages of the prototype include limited functionality, as well as large errors when measuring the average frequency in the conditions of a small input signal to noise ratio and in the presence of a priori uncertainty about the parameters of broadband signals.

The problem to which the claimed invention is directed is expanding the functionality of the device due to the possibility of simultaneous detection, classification, measurement of the amplitude, average and clock frequencies of phase-shifted signals with increased noise immunity and reduced measurement errors of signal parameters at a level less than the interference level.

The technical result is achieved by the fact that in the well-known adaptive multifunctional correlation-filter device introduced:

a) a channel for searching in frequency and detecting signals, including an input path (1), a mixer (2), a frequency-tunable generator (32), a bandpass filter with bandwidth adjustment (3), an envelope detector (6), a lower filter frequencies (7), a decisive device (8), a controller (36);

b) an adaptation channel for the average and clock frequencies of the signal, including a voltage divider (16), a phase shifter (21), a mixer (22), a band-pass filter with adjustable medium frequency (23), an envelope detector (28), a low-pass filter ( 29), threshold device (30), frequency counter (24), solving device (8), controllers (26, 27);

c) a channel for classification and accurate measurement of signal parameters, including a resolving device (8), a frequency meter (24), a threshold device (30), controllers (25, 31, 34), an adder (33), a frequency meter (35).

To achieve a technical result, an adaptive multifunctional correlation-filter device containing two mixers (4, 9), two band-pass filters (5, 18), a delay line (10), a phase shifter (13), two phase detectors (14, 17), low-pass filter (15), error signal extraction unit (19), harmonic oscillation generator (12), control element (20), stimulating signal generator (11), the first output of which is connected to the input of the frequency discriminator (37), and the second output connected to the input of the second phase detector (17); the input of the frequency detector (37) is connected to the first input of the mixer (4) and to the first input of the mixer (9), the second input of the mixer (4) is connected to the output of the delay line (10), the output of the mixer (4) is connected to the input of the bandpass filter (5 ), and the output of the bandpass filter (5) is connected to the first input of the phase detector (14), the output of the mixer (9) is connected to the input of the delay line (10), the second output of the harmonic oscillation generator (12) is connected to the input of the phase shifter (13), the output which is connected to the second input of the phase detector (14), the output of which is connected to the phi inputs tra lowpass (15) and band filter (18); the output of the low-pass filter (15) is the output of the frequency discriminator (37), the output of the bandpass filter (18) is connected to the second input of the phase detector (17), the output of which is connected to the input of the error signal isolation unit (19), the output of which is connected to the control input element (20), the output of which is connected to the control input of the harmonic oscillation generator (12) additionally introduced: input path (1), mixer (2), frequency-tunable generator (32), band-pass filter with bandwidth adjustment (3), detector envelope (6), f ltr lowpass (7), the decision unit (8), the ruler (36); voltage divider (16), phase shifter (21), mixer (22), band-pass filter with adjustable medium frequency (23), envelope detector (28), low-pass filter (29), threshold device (30), frequency counter (24), solving device (8), controllers (26, 27), solving device (8), frequency counter (24), threshold device (30), controllers (25, 31, 34), adder (33), frequency counter (35), moreover the input path (1) is the input of the inventive device, and the output of the input path (1) is connected to the first input of the mixer (2), the second input of which is connected to the first output controlled by frequency of the generator (32), the output of the mixer (2) is connected to the input of the bandpass filter with an adjustable passband (3), the control input of which is connected to the output of the controller (25), the output of the envelope detector (6) is connected to the input of the low-pass filter (7) the output of which is connected to the first input of the resolver (8) and the second input of the voltage divider (16), the second input of the resolver (8) is connected to the output of the first frequency meter (24), the third input of the resolver (8) is connected to the output of the threshold device ( 30), the fourth entrance of the decisive mouth The device (8) is connected to the output of the frequency meter (35), the control output of the deciding device (8) is connected to the inputs of the controllers (25, 26, 27, 31, 34, 36), the output of the low-pass filter (15) is connected to the first input of the voltage divider (16), the output of which is connected to the input of the controller (34), the input of the phase shifter (21) is connected to the second output of the harmonic oscillation generator (12), and the output of the phase shifter (21) is connected to the second input of the mixer (22), the output of which is connected to the input a band-pass filter with an adjustable average frequency (23), the output of which is connected to the inputs of stotomera (24) and the input of the envelope detector (28), whose output is connected to the input of a low pass filter (29) whose output is connected to the input of the threshold device (30); the output of the controller (25) is connected to the control input of the filter (3), the output of the controller (26) is connected to the control input of the delay line (10), the output of the controller (31) is connected to the control inputs of the input path (1) and the generator of stimulating signals (11) , the second output of the frequency-controlled generator (32) is connected to the input of the frequency meter (35), the output of the voltage divider (16) is connected to the input of the controller (34), the output of the controller (34) is connected to the first input of the adder (33), the output of the controller (36 ) is connected to the second input of the adder (33), the output of the adder (33) is connected to the control vlyayuschim generator input (32).

The drawing shows a structural diagram of an adaptive multifunctional correlation and filter device (AMCFU), where 1 is the input path; 3, 5, 18, 23 - band-pass filters (PF ₁ , PF ₂ , PF ₃ , PF ₄ ); 13, 21 - phase shifters (FVR ₁ , FVR ₂ ); 2, 4, 9, 22 - mixers (cm ₁ , cm ₂ , cm ₃ , cm ₄ ); 7, 15, 29 - low-pass filters (low-pass filter ₁ , low-pass filter ₂ , low-pass filter ₃ ); 6, 28 - envelope detectors (DO ₁ , DO ₂ ); 10 - delay line (LZ); 11 - generator stimulating signal (G _STS ); 12, 32 - generators (G ₁ , G ₂ ); 14, 17 - phase detectors (PD ₁ , PD ₂ ); 19 - block signal error (BVSO); 20 - control element (UE); 16 - voltage divider (Affairs); 30 - threshold device (PU); 24, 35 - counter frequency meters (Чр ₁ , Чр ₂ ); 25, 26, 27, 31, 34, 36 - managers (Ex ₁ , Ex ₂ , Ex ₃ , Ex ₄ , Ex ₅ , Ex ₆ ); 33 - adder (Sum); 8 - a decisive device (RU); 37 - frequency discriminator (BH).

The ability to achieve the objectives of the invention is confirmed by the following analysis of the operation of the device. The input path (VT) provides, using spatial and frequency selection, a discharge of the signal and interference flow to a two-component mixture at ₂ (t) = S (t) + n (t), where S (t) is the signal at the output of the VT; n (f) is the Gaussian stationary noise at the VT output.

When receiving weak broadband phase-shifted signals (PMS) with an unknown shape after they are converted in frequency in a mixer (CM ₁ ) at the output of a bandpass filter with an adjustable passband (PF ₁ ), we have:

h _f1 (t) = 2Δf _n sinc (πΔf _n t) cos (2πf _f1 t);

U _r2 (t) = U _mg2 cos (2πf _r2 t),

where h _f1 (f) - impulse response PF ₁ ; U _z2 (f) - a voltage controlled oscillator frequency (F _{2) mg2} amplitude U and the frequency f _r2; f _f1 , Δf _n is the average frequency and the maximum possible passband PF ₁ .

The voltage at ₂₀ (f) is an additive mixture:

y ₂₀ (t) = S ₀ (t) + n ₀ (t) for t ₀ ≤t≤t ₀ + T _s ;

S ₀ (t) = U _ms0 P (t) cos [ω _s0 t + φ _s0 ]; ω _s0 = 2πf _s0 ; ω _s0 = ω _s -ω _g2 ;

ω _g2 = 2πf _g2 ; f _s ∈ [f _SH, f _sre]; Δf _s ∈ [Δf _SH, Δf _sre]; φ _s0 ∈ [0,2π]; ΔF = f -f _{sre SH;}

at τ≤T _e ;

r _n (τ) = sinc (πΔf _n τ);

, N_n0 - дисперсия и спектральная плотность помехи n₀(t), t₀, Т_c - момент начала и длительность сеанса функционирования АМКФУ.where S ₀ (t), n ₀ (t) - FMS and interference n ₀ (t) at the output of PF ₁ ; U _ms0 , ω _s0 , φ _s0 — amplitude, average frequency, and initial phase of the FMS at the output of PF ₁ ; P (t) is a pseudo-random manipulating sequence; ω _s is the average frequency of the FMS at the output of the VT; f _{SH, SB} f - f _s frequency lower and upper limits; Δf _SH, Δf _sre - lower and upper limits of the spectral width Δf _s taken MBF; T _e - the duration of the element (parcel) FMS; F is the clock frequency of the FMS; R _s0 (τ), R _n0 (τ) is the FMS autocorrelation function S ₀ (t) and interference n ₀ (t); r _s (τ), r _n (τ) is the envelope of the FMS autocorrelation coefficient S ₀ (t) and interference n ₀ (t);

, N _n0 is the dispersion and spectral density of the interference n ₀ (t), t ₀ , T _c is the moment of beginning and the duration of the session of operation of the AMCFU.

The processing of FMS in AMKFU consists of five stages of adaptation. At the first stage, a frequency search and FMS detection are performed.

Process adjustment frequency F ₂ lasts as long as the condition is not executed f _s0 = f _s -f _r2 (t) ∈ [(f _Q-1 -Δf _n / 2); (f _f1 + Δf _n / 2)]. After that, the frequency search stops and the FMS is detected.

To carry out correlation-filtering processing, it is necessary to form a reference voltage of ₂₂ (t-τ _lz ), which is obtained as a result of the displacement of the process of ₂₀ (t) by a fixed frequency f _g1 and a time shift of τ _lz :

h _f (t) = 2Δf _n sinc (πΔf _n t) cos [2π (f _s0 + f _g1 ) t]; U _g1 (t) = U _mg1 cos (2πf _g1 t),

where h _f (f) is the impulse response of the band-pass filter included in the load of the mixer (Cm ₃ ) and having an average frequency f _s0 + f _g1 and a passband Δf _n ; U _g1 (t) is the voltage of the local oscillator of harmonic oscillation (G ₁ ), having an amplitude of U _mg1 and a frequency of f _g1 .

As a result of the correlation-filter processing at the output of the band-pass filter (PF ₂ ) we have the voltage:

h _p2 (t) = 2Δf _Q2 sinc (πΔf _p2 t) cos (2πf _r1 t),

where h _f2 (t) is the impulse response of a band-pass filter (PF ₂ ) having a passband Δf _f2 and an average frequency f _g1 , U ₅₁ (t) is the component due to the signal-to-signal interaction; U ₅₂ (t) is the component due to the signal-to-noise interaction; U ₅₃ (t) - a component due to the interaction of the type of "interference-interference";.

When taking FMS with an unknown form, we have

₅₁ U (t) = U _m51 P (t) P (t-τ _LZ) cos {2π [f _{r1 t + (f s0 + f r1} ) τ _LZ]} if Δf _Q2 -Δf _sre.

The FMS detection algorithm has the following form:

at t ₀ ≤t≤t ₀ + Δt ₁ ;

Δt ₁ = ΔFT ₁ / 2Δf _n ;

where H ₀ - the hypothesis of the detection of FMS; U ₇ (T ₁ ) - voltage at the output of the low-pass filter (low-pass filter ₁ ), having a constant accumulation time T ₁ ; U _por1 - normalized threshold upon detection; To _p - coefficient of proportionality with a dimension of 1 / V; Δt ₁ - the duration of the first stage of processing FMS.

Δf_n≥f_sв; Δf_ф2≈Δf_sв и Δf_ф2T₁>>1 за счет нормализации напряжения U₇(T₁) можно использовать следующие соотношения:Analysis of the characteristics of the detection of PMS, taking into account the methodology described in [1], shows that for

Δf _n ≥f _{sre; Q2} ≈Δf _sre Δf and Δf _p2 >> 1 T ₁ due to the normalization ₇ U (T _1), the voltage can use the following relations:

α ₁ = 1-F (g _p ),

- отношение сигнал/помеха по мощности на выходе ПФ₁; g₀ - отношение сигнал/помеха по напряжению на выходе ФНЧ₁; g_п - нормированный порог в РУ; g_ф - отношение сигнал/помеха по напряжению на выходе ПФ₂.where D ₁ , α ₁ - probabilities of correct detection and false alarms; Ф (x), arc Ф (х) - Laplace function and inverse Laplace function;

- the signal-to-noise ratio in power at the output of PF ₁ ; g ₀ - signal-to-noise ratio by voltage at the output of the low-pass filter ₁ ; g _p - normalized threshold in RU; g _f - the signal-to-noise ratio for the voltage at the output of the PF ₂ .

After a signal is detected by commands from the switchgear, the frequency search stops due to disconnection of the controller (Ex ₆ ) and preliminary tuning of the frequency G ₂ begins by connecting the controller (Ex ₅ ), which corresponds to the second stage of adaptation, during which preliminary elimination of the a priori uncertainty about frequency f _s FMS until the condition is reached

f _s -Δf _r2 (t) = f _s0 → f _Q-1 at t ₀ + Δt ₀ ≤t≤t ₁ + Δt ₁ + Δt ₂

where Δt ₂ - the duration of the stage of preliminary adjustment of the frequency of the local oscillator G ₂ .

At this stage of operation of the AMCFU, the voltage at the output of the low-pass filter _{2 is} used as the error signal

Given that

U ₁₃ (t) = U _mг1 cos [2πf _г1 t + φ _фвр1 ], we obtain for

φ _fvr1 = π / 2;

where T ₂ is the accumulation time constant in the low-pass filter ₂ ; U ₅₁ (t) - output voltage

PF ₂ ; U ₁₃ (t) is the voltage at the output of the phase shifter (FVR ₁ ); δφ is the phase shift due to the imperfect hardware implementation of AMCFU; φ _fvr1 is the phase shift introduced by fvr ₁ .

To ensure the invariance of the error signal to a change in the amplitude of the signal S (f) in the voltage divider (Del), normalization is carried out and at the same time, at the output of Del at 2πf _g1 τ _lz + δφ = 2πk, where k is an integer, we have a discriminatory characteristic in the form

U ₁₆ (t) = sin {2π [f _s −f _r2 (t)] τ _ls } → 0.

Since the discriminatory characteristic of the correlation-filter frequency discriminator in the general case is a periodic function, this raises the "ambiguity problem" when adjusting the frequency G ₂ .

To eliminate ambiguity, it is necessary that the delay value is selected from the condition

τ _ls = τ ₀ = 1 / 2Δf _n .

As shown in [1], the root-mean-square fluctuation error of tuning the frequency of the local oscillator G ₂ σf ₁ can be calculated from the following relationships:

σf ₁ = 1 / S ₁ g _f1 ; S ₁ = πΔf _n ;

where S ₁ - the steepness of the discriminatory characteristics at τ ₀ = 1 / Δf _n ; g _f1 is the signal-to-noise ratio by voltage at the output of the low-pass filter ₂ .

After the stage of preliminary adjustment of the frequency of the local oscillator G _{2 is completed} , the third adaptation stage begins, which provides a classification of the received signal and estimation of the clock frequency F and the spectrum width of the FMS while optimizing the noise immunity of the AMFU. To this end, commands are sent from the switchgear to disable the controllers (Ex. ₅ and Ex. ₆ ) and connect the controllers (Ex. ₂ and Ex. ₃ ).

During this adaptation stage, synchronous adjustment of the time shift introduced by the delay line (LZ) τ _lz (t) and the average frequency of the bandpass filter (PF ₄ ) f _f4 (t) is carried out.

The voltage at the output of the mixer (see ₄ ) in the presence of the input signal AMKFU only signal has the form:

where h (t) is the impulse response of the linear circuits at the output of Cm ₄ .

Given that

U ₂₁ (t) = U _mg2 cos (2πf _g1 t + φ _fvr2 ) for 2πf _g1 τ _ls + δφ-φ _fvr2 = 2πk we have

where I (τ _lz ) is an integral whose value depends on τ _lz ; φ _fvr2 - phase shift introduced by the phase shifter (fvr ₂ ).

The energy spectrum of the integral I (τ _ls ) consists of three normalized components [4]:

G (f, τ _ls ) = G ₁ (f, τ _ls ) + G ₂ (f, τ _ls ) + G ₃ (f, τ _ls );

where G ₁ (f, τ _lz ) is the spectrum of the 1st component, which is a constant component of the output effect; G ₂ (f, τ _лз ) - spectrum of the 2nd component with a discrete character; С ₃ (f, τ _лз ) is the spectrum of the 3rd component, which has a continuous character, corresponding to the “intrinsic noise” of the FMS.

To extract information about the clock frequency F of manipulation of the FMS is expedient to use at the output of the mixer (see ₄₎ bandpass filter with adjustable mean frequency (PF ₄₎ with the impulse response

h _F4 (t) = 2Δf _F4 sinc (πΔf _F4 t) cos (2πf _F4 t),

where Δf _f4 , f _f4 is the passband and the average frequency of the bandpass filter PF ₄ .

In the general case, with an a priori unknown frequency of manipulation, the F component

G ₂ (f, τ _лз ) at the output of PF _{4 is} not allocated, since f _f4 ≠ F. This leads to the need for the aforementioned restructuring τ _lz (t) and f _f4 (t).

When implementing the discrete-step law of adjustment for

t ₀ + Δt ₁ + Δt ₂ ≤t≤t ₀ + Δt ₁ + Δt ₂ + T _τ we have:

τ _ls (t) = τ ₀ + (i-1) Δτ; τ ₀ = 1 / 2Δf _n ; Δτ = Δf _F4 / 2F (F _in -Δf _F4);

f _f4 (t) = F _in - (i-1) Δf _f4 ; F ₀ = Δf _n ; i∈ [1, n _w ]; Δf = Δf _f4 ;

n _w = (τ _lsv −τ ₀ ) / Δτ; T _τ = n _w T ₃ ; τ _lsv = 1/2 F _n ,

where T _τ is the maximum time interval necessary for the implementation of search procedures [τ _lz (t), f _f4 (t)]; τ ₀ , F ₀ - the initial value of τ _lz and f _f4 ; Δτ, Δf is the magnitude of the tuning step τ _lz and f _f4 ; n _w - the maximum possible number of steps of the adjustment during the search; τ _lzv is the upper limit of the tuning range τ _lz (t); T ₃ - the time constant of the accumulation of the low-pass filter (low-pass filter ₃ ).

In the process of perestroika, the maximum value of the component G ₂ (f, τ _lz ) is achieved when the conditions τ _lz (t) → T _e / 2 → 1 / 2F and f _f4 (f) ∈ [(F-Δf _Ф4 / 2); (F + Δf _f4 / 2)] required to terminate the search.

To classify the received signal S (t), the component G ₂ (f, τ _лз ), which is characteristic only of the FMS, is used as an informative feature.

The FMS classification algorithm has the form:

при t_i≤t≤t_i+T₃,

when t _i ≤t≤t _i + T ₃ ,

where N _FM - the hypothesis of taking FMS; U ₃₀ (T ₃ ) - voltage at the output of the low-pass filter (low-pass filter ₃ ); U ₂₃ (t) is the voltage at the output of the PF ₄ ; U _por3 - threshold voltage in the threshold device (PU); t _i is the moment of time corresponding to the beginning of the i-th step of adjustment of the LZ and PF ₄ .

When triggered PU in RU receives information corresponding to the hypothesis

по которой устанавливается оценка временного сдвига

и оценка средней частоты ПФ₄

_ф4i. После этого с РУ на Упр₂ и Упр₃ подается команда на прекращение перестройки ЛЗ и ПФ₄.N _FM and estimation of the adjustment step number

which is used to estimate the time shift

and estimation of the average frequency of PF ₄

_ф4i . After that, from RU to Upr ₂ and Upr ₃ a command is issued to stop the restructuring of LZ and PF ₄ .

в течение интервала времени Т_F, информация о которой подается в РУ.From the output of the control panel, a command is also sent to connect a frequency meter (Ch ₁ ) to evaluate the manipulating frequency

during the time interval T _F , information about which is supplied to the RU.

The third stage of information processing in the AMCFU is implemented for the time interval Δt ₃ = T _τ + T _F.

The probability of erroneous decisions in the classification of FMS R _cl can be calculated from the relations [1]:

α₂=1-Ф(g_п2)P _cells = 0.5 (β ₂ + α ₂ ); β ₂ = 1-D ₂ ;

α ₂ = 1-F (g _p2 )

where β ₂ , α ₂ are the probabilities of missing the signal and false alarm; g _τ , g _F - signal-to-noise ratio by voltage at the output of the low-pass filter ₃ and PF ₄ ; g _p2 - normalized threshold in PU.

When using the counter method of frequency estimation, the relative mean square fluctuation error of frequency estimation is [5]:

σF / F = 1 / 2πmg _F , m = FT _F ,

where m is the number of periods of the manipulating frequency F per evaluation session T _F.

а затем производится уточнение оценок амплитуды

средней

и манипулирующей

частот ФМС.During the fourth stage of the information processing is performed in early AMKFU tuning bandwidth Δf PD _{1 Q-1} to bring it into line with the estimate of the signal spectrum width

and then the amplitude estimates are refined

middle

and manipulating

FMS frequencies.

To adjust the IF passband output RC ₂ in the ruler ₍₁ Cont) supplied target designation, corresponding

а крутизна дискриминационной характеристики S_т возрастает и становится равной

As a result of adaptation, when processing information at AMKFU, the errors in the estimation of parameters are reduced, since the passband of PF _{1 is} reduced to

and the steepness of the discriminatory characteristic S _t increases and becomes equal

из следующих соотношений:In view of the foregoing, the adjusted mean square fluctuation errors in estimating the FMS parameters can be calculated for

of the following ratios:

σf _t = 1 / S _t g _ft ;

σF _t / F = 1 / 2πmg _Ft ;

where g _from , g _fr , g _Ft are the signal-to-noise ratios for the voltage at the output of the low-pass filter ₁ , low-pass filter ₂ , low-pass filter ₃ after adaptation and elimination of the influence of a priori uncertainty about the frequency f _s and the spectrum width Δf _{s of the} FMS.

- оценка частоты гетеродина Г₂, которая фиксируется частотомером Чр₂ в ходе четвертого этапа адаптации и передается в РУ. Четвертый этап обработки информации в АМКФУ реализуется за интервал времени Δt₄=Г_Δfф+T_f, где Т_Δfф - время, необходимое для подстройки полосы пропускания ПФ₁; T_f - время, необходимое для оценки частоты генератора Г₂.The FMS frequency estimate is

- an estimate of the frequency of the local oscillator G ₂ , which is recorded by the frequency meter Ch ₂ during the fourth stage of adaptation and transmitted to the RU. The fourth stage of information processing in the AMCFU is implemented for the time interval Δt ₄ = Г _Δff + T _f , where T _Δff is the time required to adjust the passband PF ₁ ; T _f - the time required to estimate the frequency of the generator G ₂ .

In cases where when estimating the signal frequency f _{s it} is necessary to eliminate the hardware error due to the instability of the laser, it is advisable to periodically use the fifth stage of information processing in the AMCFU, which provides the calibration mode of the laser.

что и обеспечивает устранение смещенности нуля дискриминационной характеристики за счет аппаратурного фазового сдвига δφ. Длительность пятого этапа Δt₅ определяется постоянной времени УЭ Т_уэ. После завершения пятого этапа по командам с РУ Г_стс отключается, а ВТ включается.At the same time, by commands from the switch-off, the VT is turned off and the generator of the stimulating signal (G _sts ) is _{turned on} . As a result of processing the stimulating signal, an error signal is generated at the output of the error signal isolation device (UVCO), which, through the control element (UE), adjusts the frequency of the generator G ₁ so that the condition

which ensures the elimination of the zero bias of the discriminatory characteristic due to the hardware phase shift δφ. The duration of the fifth stage Δt ₅ is determined by the time constant of UE T _ue . After the completion of the fifth stage, according to commands from the RU G, the _{HSS is} turned off, and the VT is turned on.

The total duration of the FMS processing session in the AMCFU is

where Δt _j is the duration of the j-th stage of the functioning of AMCFU.

Δf_n=2,5·10⁷ Гц; Δf_ф1=2·10⁷ Гц; T₁=10^-2 c; τ₀=1/2Δf_n=2·10^-8 с; Т₂=10^-2 с; Т_F=10^-2 с; Т₃=10⁴ с; Δf_ф4=10⁵ Гц.To illustrate the obtained relations, we consider an example with the following initial data: ΔF = 6 · 10 ⁷ Hz; F _n = 10 ⁶ Hz; F _in = 10 ⁷ Hz;

Δf _n = 2.5 · 10 ⁷ Hz; Δf _f1 = 2 · 10 ⁷ Hz; T ₁ = 10 ^-2 s; τ ₀ = 1 / 2Δf _n = 2 · 10 ^-8 s; T ₂ = 10 ^-2 s; T _F = 10 ^-2 s; T ₃ = 10 ⁴ s; Δf _f4 = 10 ⁵ Hz.

When using AMCFU without adaptation as a result of the express analysis of FMS, we have:

D ₁ = 0.85; α ₁ = 10 ^-5 ; σU _ms / U _ms = 0.2; σf ₁ = 10 ⁵ Hz; P _cells = 10 ^-3 ; σF ₁ = 20 Hz; T _c = 5 · 10 ^-2 s.

When using AMCFU adaptation when receiving FMS with a spectrum width Δf _s = 2 · 10 ⁶ Hz we have:

D _1a → 1; α ₁ = 10 ^-5 ; σU _mst / U _ms = 5 · 10 ^-3 ; σf _t = 1.9 · 10 ³ Hz; P _cells → 0; σF ₂ = 1.5 Hz; Tc = 10 ^-1 s.

Thus, the proposed device provides operational radio monitoring of weak broadband FMS with enhanced functionality and reduced estimation errors of the main parameters (U _ms , F, f _s ) and increased noise immunity in the detection and classification of FMS.

The implementation of the device is not difficult. All its functional units are typical and can be made on the basis of a modern elemental base.

Information sources

1. Dyatlov A.P. Correlation devices in radio navigation. Part I, II. - Taganrog: TRTI, 1988.

2. Auth. St. USSR No. 936374, op. BI No. 22, 1982.

3. Whistlers V.M. Radar signals and their processing. - M .: Owls. Radio, 1977.

4. Spilker J. Digital satellite communications. - M.: Communication, 1979.

5. Equipment for frequency and time measurements. Ed. A.P. Gorshkova. - M .: Owls. Radio, 1971.

Claims (1)

An adaptive multifunctional correlation filter device containing two mixers (4, 9), two band-pass filters (5, 18), a delay line (10), a phase shifter (13), two phase detectors (14, 17), a low-pass filter (15 ), an error signal isolation unit (19), a harmonic oscillation generator (12), a control element (20), a stimulating signal generator (11), the first output of which is connected to the input of the frequency discriminator (37), which corresponds to the output of the bandpass filter (3) and the second output of the generator of stimulating signals (11) is connected to the input m second phase detector (17); the input of the frequency detector (37), that is, the output of the bandpass filter (3), is connected to the first input of the mixer (4) and to the first input of the mixer (9), the second input of the mixer (4) is connected to the output of the delay line (10), the output of the mixer (4) is connected to the input of the band-pass filter (5), and the output of the band-pass filter (5) is connected to the input of the envelope detector (6), with the first input of the phase detector (14) and with the first input of the mixer (22), the second input of the mixer (9) ) is connected to the first output of the generator (12), and the output of the mixer (9) is connected to the input of the delay line (10), the second output of the generator harmonic oscillations (12) is connected to the input of the phase shifter (13), the output of which is connected to the second input of the phase detector (14), the output of which is connected to the inputs of the low-pass filter (15) and the band-pass filter (18); the output of the low-pass filter (15) is the output of the frequency discriminator (37), the output of the bandpass filter (18) is connected to the second input of the phase detector (17), the output of which is connected to the input of the error signal isolation unit (19), the output of which is connected to the control input element (20), the output of which is connected to the control input of the harmonic oscillation generator (12), characterized in that it has an input path (1), a mixer (2), a frequency tunable generator (32), a bandpass filter with bandwidth adjustment (3), detector about bending (6), low-pass filter (7), solving device (8), ruler (36); voltage divider (16), phase shifter (21), mixer (22), band-pass filter with adjustable medium frequency (23), envelope detector (28), low-pass filter (29), threshold device (30), frequency counter (24), rulers (26, 27); controllers (25, 31, 34), an adder (33), a frequency meter (35), the input of the input path (1) being the input of the inventive device, and the output of the input path (1) connected to the first input of the mixer (2), the second input of which connected to the first output of a frequency-controlled generator (32), the output of the mixer (2) connected to the input of a bandpass filter with an adjustable passband (3), the input of the envelope detector (6) is connected to the output of the bandpass filter (5), and the output of the envelope detector ( 6) connected to the input of the low-pass filter (7), the output of which is connected to the first input the house of the solving device (8) and the second input of the voltage divider (16), the second input of the solving device (8) is connected to the output of the first frequency meter (24), the third input of the solving device (8) is connected to the output of the threshold device (30), the fourth input of the solving device (8) is connected to the output of the frequency meter (35), the control output of the deciding device (8) is connected to the inputs of the controllers (25, 26, 27, 31, 34, 36), the output of the low-pass filter (15) is connected to the first input of the voltage divider (16), the output of which is connected to the input of the controller (34), the input of the phase shifter (21) with is single with the second output of the harmonic oscillation generator (12), and the output of the phase shifter (21) is connected to the second input of the mixer (22), the output of which is connected to the input of the bandpass filter with an adjustable average frequency (23), the output of which is connected to the inputs of the frequency meter (24) and the input of the envelope detector (28), the output of which is connected to the input of the low-pass filter (29), the output of which is connected to the input of the threshold device (30), the output of the threshold device (30) is connected to the control input of the frequency meter (24) and the second input of the deciding device (8), exit the controller (25) is connected to the control input of the filter (3), the output of the controller (26) is connected to the control input of the delay line (10), the output of the controller (31) is connected to the control inputs of the input path (1) and the stimulating signal generator (11), the second output of the frequency-controlled generator (32) is connected to the input of the frequency meter (35), the output of the voltage divider (16) is connected to the input of the controller (34), the output of the controller (34) is connected to the first input of the adder (33), the output of the controller (36) connected to the second input of the adder (33), the output of the adder (33) is connected to the control generator input (32).