RU2559750C1 - Calculator of doppler phase of passive interference - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: calculator of Doppler phase of passive interference includes a phase estimation unit, a complex multiplication unit, a delay unit, a synchronising pulse generator, the first multiplier, the first functional converter, the second multiplier, the second functional converter, the first memory unit, a complex adder, an additional phase calculator, the second memory unit, an additional phase estimation unit, the third and fourth functional converters, an additional complex multiplication unit and an additional delay unit.

EFFECT: improving measurement accuracy of the current value of Doppler phase of multifrequency passive interference.

9 dwg

Description

The invention relates to computer technology and is intended for calculation based on the correlation principle of Doppler phase shifts of passive interference; can be used in adaptive passive interference rejection devices to calculate trigonometric functions (cosine and sine) of the current values of the Doppler phase of multi-frequency passive interference.

Known computer Doppler phase passive interference, containing a delay unit, a complex conjugation unit, a complex multiplication unit and the first and second division blocks [1]. However, this device has a low accuracy in measuring the Doppler phase of passive interference.

Also known is a computer comprising a delay unit, a complex multiplication unit, a first and second averaging units and a first and second division unit [2], while the inputs of the delay unit and a complex multiplication unit are interconnected, the first output of the complex multiplier through the first averaging unit is connected to the first input of the first division unit, the second output of the complex multiplier through the second averaging unit is connected to the first input of the second division unit. However, this device has a low measurement accuracy.

Closest to the invention is a passive interference Doppler phase meter [3], selected as a prototype, comprising a phase estimation unit, a first complex multiplication unit and a first delay unit, the phase evaluation unit contains a second delay unit, the outputs of which are connected to the inputs of the complex conjugation unit, the outputs of the complex conjugation unit are connected to the first inputs of the second complex multiplication unit, the second inputs of which are combined with the inputs of the second delay unit, which are the inputs of the meter, and that the averaging unit and the phase calculator, whose output is the output of phase estimation unit. However, this device has low accuracy in measuring the current value of the Doppler phase of passive interference.

The problem solved in the invention is to increase the accuracy of measuring the current value of the Doppler phase of multi-frequency passive interference through the use of joint processing of the frequency components of multi-frequency passive interference.

To solve the problem, the first and second multipliers, the first, second, third and fourth functional converters, the first and second memory blocks, and the complex adder are introduced into the Doppler passive jammer, which contains a phase estimator, a complex multiplier, a delay unit, and a clock generator. additional phase calculator, additional phase estimation unit, additional complex multiplication unit and additional delay unit.

Additional blocks introduced into the proposed device are known. So, the delay unit, the complex conjugation unit, the complex multiplication unit, the averaging unit, and the phase calculator connected together in the phase estimation block, allow us to isolate the Doppler phase advance for the interval between adjacent passive interference samples. However, the combined use of the complex multiplication block, the delay block, the first and second multipliers, the first, second, third and fourth functional converters, the first and second memory blocks, the complex adder, the additional phase calculator, the additional phase estimation block, the additional complex multiplication block, and the additional delay block. The connections of the first multiplier with the phase estimator, the first functional converter and the first memory block, the additional phase estimator with the third functional converter, the first and third functional converters with the complex adder, the complex adder with the additional phase calculator, the additional phase calculator with the second multiplier, and fourth functional converter, second and fourth functional converters, respectively, with the unit complex multiplication and an additional unit of complex multiplication, which improves the accuracy of measuring the current value of the Doppler phase of multi-frequency passive interference. The connections between the sync generator and all the blocks of the Doppler passive jam calculator provide consistent processing of the frequency components of the multi-frequency passive interference.

Comparison with the technical characteristics known from published sources of information shows that the claimed solution has novelty and has an inventive step.

The claimed solution is technical in nature, feasible, reproducible and, therefore, is industrially applicable.

In FIG. 1 is a structural electrical diagram of a Doppler passive jammer; in FIG. 2 - phase estimation unit; in FIG. 3 - delay unit; in FIG. 4 - block complex conjugation; in FIG. 5 - block complex multiplication; in FIG. 6 - averaging unit; in FIG. 7 - phase calculator; in FIG. 8 - character assignment unit; in FIG. 9 - complex adder.

The calculator of the Doppler phase of passive interference (Fig. 1) contains a phase estimator 1, a complex multiplier 2, a delay unit 3, a first multiplier 4, a first functional converter 5, a second multiplier 6, a second functional converter 7, a first memory unit 8, a complex adder 9, an additional phase 10 calculator, a second memory unit 11, an additional phase estimation unit 12, a third 13 and a fourth 14 functional converters, an additional complex multiplication unit 15, an additional delay and sync generator unit 16 OP 17, while the outputs of the complex multiplication block 2 are connected to the inputs of the delay block 3, the outputs of which are connected to the first inputs of the complex multiplication block 2, the output of the phase estimation block 1 is connected to the first input of the first multiplier 4, the second input of which is connected to the output of the first block 8 memory, the output of the first multiplier 4 is connected to the input of the first functional converter 5, the outputs of which are connected to the first inputs of the complex adder 9, the outputs of the complex adder 9 are connected to the inputs of an additional calculator phase 10, the output of which is connected to the combined first input of the second multiplier 6 and the input of the fourth functional converter 14, the second input of the second multiplier 6 is connected to the output of the second memory unit 11, the output of the second multiplier 6 is connected to the input of the second functional converter 7, the outputs of which are connected to the second the inputs of block 2 of the complex multiplication, the output of the additional block 12 phase evaluation is connected to the input of the third functional Converter 13, the outputs of which are connected to the second inputs of the complex of the adder 9, the outputs of the fourth functional converter 14 are connected to the first inputs of the additional complex multiplication unit 15, the second inputs of which are connected to the outputs of the additional delay complex unit 16, the inputs of which are connected to the outputs of the sync generator 17 connected to the sync inputs of the evaluation unit 1 phase, block 2 complex multiplication, block 3 delay, the first multiplier 4, the first functional converter 5, the second multiplier 6, the second functional converter 7, first memory unit 8, complex adder 9, additional phase 10 calculator, second memory unit 11, additional phase estimation unit 12, third 13 and fourth 14 functional converters, additional complex multiplication unit 15 and additional delay unit 16, the first and the second inputs of the Doppler passive noise phase calculator are respectively the inputs of the phase estimator 1 and the additional phase estimator 12, and the first and second outputs are respectively the outputs block 2 of complex multiplication and an additional block 15 of complex multiplication.

The phase estimating unit 1 and the additional phase estimating unit 12 (Fig. 2) comprise a series-connected delay unit 18, complex conjugation unit 19, complex multiplication unit 20, averaging unit 21, and phase 22 calculator, the second inputs of complex multiplication unit 20 are combined with inputs of the unit 18 delays are the inputs of the phase estimation blocks, the outputs of which are the outputs of the phase 22 calculators.

Blocks 3 and 18 of the delay and an additional block of delay 16 (Fig. 3) contain two digital delay lines 23 for the interval T, the input of the delay blocks are the inputs of the digital delay lines 23, the outputs of which are the outputs of the delay blocks.

The complex conjugation block 19 (Fig. 4) contains an inverter 24, the first input of the complex conjugation block is its first output, the second input is the inverter input, the output of which is the second output of the complex conjugation block.

Blocks 2 and 20 of complex multiplication and an additional block 15 of complex multiplication (Fig. 5) contain two channels (I, II), each of which includes a first multiplier 25, serially connected a second multiplier 26 and an adder 27, the output of the first multiplier 25 of one channel is connected with the second input of the adder 27 of the other channel, and the first and second inputs of the complex multiplication block, respectively, are the combined first inputs of the first and second multipliers 25, 26 of each channel, the combined second inputs of the second trans multiplier 26 and the combined first inputs of the second multipliers 25 and the output unit are complex multiplication outputs of adders 27 of each of the channels.

The averaging block 21 (Fig. 6) contains two channels (I, II), each of which consists of n sequentially connected digital delay elements 28 for the time sampling interval and n-1 adders in series 29, the inputs of the averaging block are the combined inputs of the first element delays 28 and the first adder 29 of each channel (I, II), and the output of the k-th (k = 1 ... n) delay element 28, except for the (n / 2) th, is connected to the second input of the k-th (k = 1 ... n-1) of the adder 29 of each channel (I, II), the outputs of the averaging block are the outputs of the (n-1) -x adders.

The phase 22 calculator and the additional phase 10 calculator (Fig. 7) consist of a series divider 30, a functional converter 31, a modular block 32, an adder 33, a character assignment unit 34 and a first key 35, the output of the functional converter 31 is connected to the input of the second key 36 , the second input of the adder 33 is connected to the output of the memory unit 38, the control inputs of the first and second keys 35, 36 are connected to the input of the divider 30 corresponding to the input of the real part of the complex number, the second input of the connection sign assignment unit 34 n to the input of the divider 30, the corresponding entry of the imaginary part of a complex number, the outputs of the first and second keys 35, 36 are connected to inputs of an adder 37 whose output is the phase output of the calculator, the calculator inputs are phase divider 30 inputs.

The character assignment unit 34 (FIG. 8) comprises multiplication units 39, 42, a memory unit 40 and a limiter 41, the second input of the character assignment unit being the first input of the multiplication unit 39, the second input of which is connected to the output of the memory unit 40, the output of the multiplying unit 39 connected to the input of the limiter 41, the output of which is connected to the first input of the multiplication unit 42, the second input of which is the first input of the character assignment unit, the output of the character assignment unit is the output of the multiplication unit 42.

The complex adder 10 (Fig. 9) contains two adders 43, the first inputs of which are the first inputs of the complex adder, and the second inputs are the second inputs of the complex adder, the outputs of the adders are the outputs of the complex adder.

The calculator Doppler phase of passive interference works as follows.

Two frequency components of multi-frequency passive interference, significantly exceeding the signal from the target, are separately fed to the inputs of the receivers of each frequency channel, in which they are amplified, are transferred to the video frequency in quadrature phase detectors, and then undergo analog-to-digital conversion (the corresponding blocks in Fig. 1 are not shown ) The first and second inputs of the calculator in each resolution element in the range of each repetition period receive digital samples of the complex envelopes of the corresponding frequency components of the interference

,

,

- цифровые коды действительной и мнимой частей отсчетов

; j и k - текущие номера соответственно периода повторения и элемента разрешения по дальности, причем

; l - номер частотного компонента, причем l=1, 2; φ_0l - начальная фаза l-го частотного компонента; φ_l - доплеровский сдвиг фазы l-го частотного компонента помехи, равныйWhere

- digital codes of the real and imaginary parts of the samples

; j and k are the current numbers of the repetition period and the range resolution element, respectively, and

; l is the number of the frequency component, with l = 1, 2; φ _0l is the initial phase of the l-th frequency component; φ _l - Doppler phase shift of the l-th frequency component of the interference, equal to

φ _l = 2πf _dl T = 4πv _r f _нl T / c, l = 1, 2,

where f _dl = 2v _r f _nl / c is the Doppler interference frequency; Τ is the repetition period of the probe pulses; v _r is the radial velocity of the source of interfering reflections (passive interference); f _nl is the carrier frequency of the l-th frequency component, and f _n2 = rf _nl , r <1; C is the propagation velocity of radio waves.

и

поступают соответственно на входы блока 1 оценивания фазы и дополнительного блока 12 оценивания фазы (фиг. 2), где в блоках 18 задержки (фиг. 3) задерживаются на период повторения Т. После этого в блоках 19 комплексного сопряжения (фиг. 4) путем инвертирования с помощью инвертора 24 знаков проекций у осуществляется комплексное сопряжение задержанных отсчетов

. Далее в блоках 20 комплексного умножения (фиг. 5) в каждом элементе разрешения по дальности реализуется попарное умножение отсчетов в соответствии с алгоритмом вычисления корреляцийIn the computer (Fig. 1) readings

and

arrive respectively at the inputs of the phase estimator 1 and the additional phase estimator 12 (Fig. 2), where in the blocks 18 the delays (Fig. 3) are delayed by the repetition period T. After that, in the complex coupling blocks 19 (Fig. 4) by inverting with the help of an inverter of 24 signs of projections y, complex conjugation of delayed samples is carried out

. Further, in blocks 20 of complex multiplication (Fig. 5), in each element of the range resolution, pairwise multiplication of samples is implemented in accordance with the algorithm for calculating correlations

поступают в блоки 21 усреднения (фиг. 6), осуществляющие с помощью элементов 28 задержки и сумматоров 29 скользящее вдоль дальности в каждом периоде повторения суммирование корреляций

с n+1 смежных элементов разрешения по дальности временного строба, кроме элемента с номером n/2+1, для чего выходные величины элемента 28 задержки с номером n/2 поступают только на последующий элемент 28 задержки (фиг. 6). При этом на выходах блоков 21 усреднения образуются пропорциональные корреляционным моментам отсчетов, соответствующих каждому частотному компоненту, величиныFrom the outputs of the complex multiplication blocks 20, the resulting pairwise products (correlations)

enter the averaging units 21 (Fig. 6), which, using delay elements 28 and adders 29, summarize the correlations moving along the range in each repetition period

from n + 1 adjacent resolution elements along the range of the time strobe, except for the element with the number n / 2 + 1, for which the output values of the delay element 28 with the number n / 2 go only to the subsequent delay element 28 (Fig. 6). In this case, at the outputs of the averaging blocks 21, values proportional to the correlation moments of the samples corresponding to each frequency component are formed,

, l=12, аргументами которых являются межпериодные доплеровские сдвиги фазы помехи

в j-м периоде повторения l-го частотного компонента (l=1, 2).

, l = 12, the arguments of which are inter-period Doppler shifts of the interference phase

in the j-th repetition period of the l-th frequency component (l = 1, 2).

и

в блоках 1 и 12 поступают на соответствующие входы вычислителей фазы 22 (фиг. 7), где на основе блоков 30 деления и арктангенсных функциональных преобразователей 31 вычисляются оценкиQuantities

and

in blocks 1 and 12 are supplied to the corresponding inputs of the phase 22 calculators (Fig. 7), where, based on the division blocks 30 and the arctangent functional converters 31, the estimates are calculated

, l=1, 2.

, l = 1, 2.

зависят от знака величины

. При

открыт второй ключ 36, и оценка

через сумматор 37 непосредственно поступает на выход вычислителя фазы 22. При

открыт первый ключ 35, а второй ключ 36 закрыт. При этом в модульном блоке 32 образуется

, вычитаемый в сумматоре 33 из величины π, поступающей от блока 38 памяти. Полученной разности в блоке 34 присваивается знак величины

.Subsequent grade conversions

depend on the sign of the quantity

. At

the second key is open 36 and the score

through the adder 37 directly goes to the output of the phase 22 computer.

the first key 35 is open, and the second key 36 is closed. Thus in the modular block 32 is formed

subtracted in the adder 33 from the value of π coming from the block 38 of the memory. The resulting difference in block 34 is assigned a sign of magnitude

.

, где в блоке 39 умножения производится ее умножение на постоянный множитель из блока 40 памяти с целью масштабирования и дальнейшего ограничения в ограничителе 41 по уровню ±1. Таким образом, после ограничения величина на выходе ограничителя 41 имеет смысл знака величины

, который, поступая на первый вход блока 42 умножения, присваивается разности

, поступающей с выхода сумматора 33 на первый вход блока 34 присвоения знака, т.е. на второй вход блока 42 умножения.Block 34 character assignment (Fig. 8) works as follows. The second input of the block 34 character assignment receives the value

, where in the block 39 multiplication it is multiplied by a constant factor from the block 40 of the memory in order to scale and further limit the limiter 41 to the level of ± 1. Thus, after the restriction, the value at the output of the limiter 41 has the meaning of the sign of the quantity

which, entering the first input of the multiplication block 42, is assigned the difference

coming from the output of the adder 33 to the first input of the character assignment unit 34, i.e. to the second input of the multiplication block 42.

The operations considered allow the phase 22 calculator to first find an estimate of the Doppler phase shift of the interference located in the interval [-π / 2, π / 2], and then, using subsequent logical transformations in blocks 32, 33 and 34, expand the limits of its unambiguous measurement to the interval [-π, π] according to the algorithm

на коэффициент r, хранящийся в первом блоке 8 памяти, что приводит к получению пересчитанной по отношению ко 2-му частотному каналу оценкиThe first multiplier 4 (Fig. 1) multiplies the phase found in block 1 of the evaluation of the 1st frequency channel evaluation

by the coefficient r stored in the first memory block 8, which leads to the recalculation of the estimate relative to the 2nd frequency channel

.

.

и найденная в дополнительном блоке 12 оценивания фазы 2-го частотного канала оценка

подвергаются межканальному усреднению. Так как непосредственное усреднение оценок

и

вследствие цикличности фазовых сдвигов приводит к существенным ошибкам, то усреднению подлежат тригонометрические функции этих оценок. Для этого в первом 5 и третьем 13 косинусно-синусных функциональных преобразователях определяются соответственно величиныThis recalculated estimate

and the estimate found in the additional phase estimator 12 of the 2nd frequency channel

are subjected to inter-channel averaging. Since direct averaging of estimates

and

due to the cyclical nature of the phase shifts leads to significant errors, then the trigonometric functions of these estimates are subject to averaging. For this, in the first 5 and third 13 cosine-sine function converters, the quantities

,

.

,

.

Interchannel averaging is carried out in the complex adder 9 (Fig. 9) by separately summing the real and imaginary projections of the input quantities, leading to the calculation of the output quantity

.

.

In the additional phase 10 calculator (Fig. 7), the average estimate for the 2nd frequency channel is determined:

.

.

In the second multiplier 6, this estimate is multiplied by the coefficient 1 / r stored in the second memory block 11, which leads to an average estimate for the 1st frequency channel:

.

.

In the second 7 and fourth 14 cosine-sine functional converters are determined respectively

,

.

,

.

The complex multiplication block 2 together with the delay block 3 and the additional complex multiplication block 15 together with the additional delay block 16 in each range resolution element carry out recurrent accumulation of estimates of the inter-period Doppler phase shift of the interference for the 1st and 2nd frequency channels, respectively:

,

,

.

.

и

Due to the homogeneity of the interference with respect to Doppler velocity within each resolution element in the range and uniformity of estimates

and

,

,

,

,

и

на соответствующую величину, но в противоположном направлении скомпенсировать доплеровские сдвиги фазы помехи.which corresponds, up to the initial phase, to the current phase of the interference, which allows by two-dimensional rotation of the samples arriving in each frequency channel

and

by an appropriate amount, but in the opposite direction, compensate for Doppler phase shifts of the interference.

и

исключить возможность ослабления или подавления сигнала от цели при последующем режектировании помехи за счет его влияния на используемые оценки.The elimination of samples from the middle element with the number n / 2 + 1 during the rolling summation in the averaging block 21 allows for temporary combination of processing with this element by a corresponding delay in the initial samples

and

exclude the possibility of attenuation or suppression of the signal from the target during the subsequent rejection of interference due to its influence on the estimates used.

The synchronization of the calculator of the Doppler phase of passive interference is carried out by applying to all blocks of the claimed device a sequence of synchronizing pulses generated by the synchronizer 17 (Fig. 1) with a repetition period equal to the time sampling interval t _d selected from the condition for the required range resolution.

в предложенном устройстве характеризуется дисперсиейThe achievement of the technical result is explained as follows. The error of the average estimate

in the proposed device is characterized by dispersion

, l=1, 2,

, l = 1, 2,

- коэффициент межпериодной корреляции помехи в l-м частотном канале (l=1, 2);

- нормированная ширина спектра помехи в l-м частотном канале (l=1, 2).where r ₁ = 1, r ₂ = r;

- inter-period correlation coefficient of interference in the l-th frequency channel (l = 1, 2);

is the normalized width of the interference spectrum in the l-th frequency channel (l = 1, 2).

для известного устройства (прототипа)Estimation variance

for a known device (prototype)

.

.

в предложенном устройстве меньше дисперсии в известном устройстве, что соответствует повышению точности оценивания, зависящей от номера частотного канала. Расчеты показывают, что при r=0,95 и β_п=Δf_пT=0,1 для 1-го частотного канала (l=1) точность оценивания повышается в 2 раза, а для 2-го частотного канала (l=2) - в 2,2 раза.As you can see, the variance of the average estimate

in the proposed device there is less dispersion in the known device, which corresponds to an increase in the accuracy of estimation, depending on the number of the frequency channel. Calculations show that for r = 0.95 and β _p = Δf _p T = 0.1 for the 1st frequency channel (l = 1), the estimation accuracy increases by 2 times, and for the 2nd frequency channel (l = 2 ) - 2.2 times.

Thus, the calculator of the Doppler phase of passive interference allows you to improve the accuracy of estimating the current value of the Doppler phase shift of multi-frequency passive interference.

Bibliography

1. A.S. 934816 (USSR), IPC G01S 7/36, G01S 13/52. Notch filter / D.I. Popov. - Publ. 11/27/1998. - Inventions. - 1998. - No. 33. - S. 407-408.

2. A.S. 1098399 (USSR), IPC G01S 7/36. Device adaptive rejection of passive interference / D.I. Popov. - Publ. 12/20/1998. - Inventions. - No. 35. - S. 377-378.

3. A.S. 1136620 (USSR), IPC G01S 7/292. Passive jammer / D.I. Popov, V.V. Smooth. - Publ. 11/27/1998. - Inventions. - 1998. - No. 33. - S. 405.

Claims (1)

A passive interference Doppler phase calculator comprising a phase estimation unit, a complex multiplication unit, a delay unit and a clock generator, wherein the outputs of the complex multiplication unit are connected to the inputs of the delay unit, the outputs of which are connected to the first inputs of the complex multiplication unit, the output of the clock generator is connected to the sync inputs of the phase estimation unit , a complex multiplication block and a delay block, characterized in that the first multiplier, the first functional converter, the second multiplier, the second function are introduced an al converter, a first memory unit, a complex adder, an additional phase calculator, a second memory unit, an additional phase estimator, a third and fourth functional converters, an additional complex multiplier and an additional delay unit, while the output of the phase estimator is connected to the first input of the first multiplier the second input of which is connected to the output of the first memory block, the output of the first multiplier is connected to the input of the first functional converter, the outputs of which are connected to the first inputs of the complex adder, the outputs of the complex adder are connected to the inputs of an additional phase calculator, the output of which is connected to the combined first input of the second multiplier and the input of the fourth functional converter, the second input of the second multiplier is connected to the output of the second memory block, the output of the second multiplier is connected to the input of the second functional converter the outputs of which are connected to the second inputs of the complex multiplication block, the output of the additional phase estimation block is connected with the input of the third functional converter, the outputs of which are connected to the second inputs of the complex adder, the outputs of the fourth functional converter are connected to the first inputs of the additional block of complex multiplication, the second inputs of which are connected to the outputs of the additional block of delay, the inputs of which are connected to the outputs of the additional block of complex multiplication, the output of the clock connected to the sync inputs of the first multiplier, the first functional converter, the second multiplier, a functional converter, a first memory unit, an integrated adder, an additional phase calculator, a second memory unit, an additional phase estimation unit, a third and fourth functional converters, an additional complex multiplication unit and an additional delay unit, the first and second inputs of the Doppler phase passive jammer being respectively, the inputs of the phase estimator and the additional phase estimator, and the first and second outputs, respectively, in outputs of the complex multiplication block and the additional complex multiplication block.

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