RU2633029C1 - Transmitting adaptive antenna array - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: transmitting adaptive antenna array comprising N antenna elements, N blocks of complex weighting signals, an adaptive processor configured of a plurality of K units of weight factor, a system of amplifiers, N digital-to-analog converters, a power distribution system, power supply, an exciter, and a modulator are further introduced, in the adaptive processor a block of the weight vector approximation is additionally introduced, and in each of the K blocks of the weight vector formation a block of the control vector formation and a block of the interference vector formation are additionally introduced.

EFFECT: ability to provide transmission of broadband signals in the necessary directions in conditions of providing radio coverage, electromagnetic compatibility of radioelectronic facilities and electromagnetic ecology.

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Description

The invention relates to antenna technology and can be used in radio communication systems for the transmission of broadband signals in the conditions of radio intelligence, as well as to ensure electromagnetic compatibility of electronic equipment and electromagnetic ecology.

Known adaptive antenna array [1, p. 56, 2] containing N antenna elements. A device with quadrature channels is introduced into the channel of each antenna element, with the help of which the signal is divided into in-phase and quadrature components, and each of the components is subjected to the operation of multiplication by the weight coefficient. The signals obtained after such processing are added to the adder. The management of the values of weights is carried out using a signal processor.

However, this adaptive antenna array is capable of processing only narrowband signals and operates only on reception.

Known adaptive antenna array [3], containing antenna elements, hybrid devices that provide separation of signals into in-phase and quadrature components, weight multipliers, a common adder, adaptive circuits, band-pass and barrage filters, power measurement units, a comparison unit and a control unit. Using filters, power measurement units, a comparison unit, and a control unit, the output power of the total adder is minimized and maximized in the modes of suppressing interference and extracting a useful signal.

The disadvantage of this adaptive antenna array is the complexity of the adaptive antenna array and the need for separate execution of the modes to minimize interference and maximize the power of the useful signal. Also, this grill is a receiving.

Known adaptive antenna array [4], containing 7Y antenna elements connected via complex weight multipliers with inputs of a common adder, N adaptive circuits, the first inputs of which are connected to the outputs of the corresponding antenna elements, and the second inputs - with the outputs of the common adder. The first outputs of adaptive circuits are connected to the corresponding inputs of complex weight multipliers. The first and second inputs of the output power maximization unit are connected respectively to the first and second outputs of the adaptive circuits, and the outputs are connected to the corresponding inputs of the adaptive circuits. The adaptive antenna array has greater noise immunity with respect to interfering signals, regardless of their frequency band.

However, it is advisable to use such an adaptive antenna array when receiving signals that have a pause during transmission, for example, signals with pseudo-random frequency tuning. In addition, the introduction of a unit for maximizing the output power and changing the connections due to this introduction significantly complicates the adaptive antenna array. This adaptive antenna array operates only on reception and cannot solve the problem of signal transmission.

To eliminate the disadvantages of devices that implement the classical method of spatial filtering of narrow-band signals, a transverse filter or a multi-tap delay line is introduced, which suppresses interference in the frequency band [1, p. 57-60].

However, the use of frequency-dependent weighting using a multi-tap delay line is associated with the selection and implementation of the necessary amplitude and phase characteristics of complex weighting factors. In the proposed analogues, devices that provide the selection and implementation of the necessary amplitude-phase characteristics of complex weighting factors are not considered. Also, the capabilities of the adaptive antenna array to function in transmission are not considered.

The closest analogue (prototype) is an adaptive antenna array [5], which includes 7Y antenna elements, integrated signal weighting units, an adaptive processor, a common adder, N bandpass filters, M signal adders and (Ml) xN integrated signal weighting units, and the adaptive processor is made in the form of M weighting units. In this case, bandpass filters are installed at the outputs of the antenna elements. The M outputs of each band-pass filter are connected directly to the corresponding inputs of the M weighting units, and to the corresponding inputs of the M signal adders via integrated signal weighting units, the outputs of the M weighting units are connected, for the corresponding frequency component of the useful signal, to the control inputs of the complex signal weighting units , the outputs of the M signal adders are connected to the inputs of the common adder.

However, when it is necessary to transmit a broadband signal and at the same time ensure radio concealment, electromagnetic compatibility of electronic equipment and electromagnetic ecology, the considered adaptive antenna array is not capable of fulfilling the task, since it is intended only for receiving broadband signals in the presence of interference.

The proposed adaptive transmitting antenna array is aimed at achieving a technical result — expanding the functionality of the function of transmitting broadband signals in the context of radio intelligence and ensuring electromagnetic compatibility of electronic equipment and electromagnetic ecology.

To achieve this technical result, an adaptive antenna array, which is the closest analogue (prototype), containing N antenna elements, N blocks of complex signal weighting, an adaptive processor made of a set of K weighting factors, an additional amplifier system, N digital-analogue ones converters, power distribution system, power source, pathogen, modulator, an approximation unit of weight vector to coefficients, and in each of the K blocks of the formation of the vector of weight coefficients, a control vector formation block and an interference vector generation block are additionally introduced, the modulator input connected to the information source, the modulator control output connected to the exciter input, the information output of the modulator connected to the information input of each N blocks of complex signal weighting, the output of the pathogen through the power distribution system is connected to the input of each of N blocks of complex weighted signals signals, the output of each of the N blocks of complex signal weighing through a digital-to-analog converter and amplifier system is connected to the input of the corresponding antenna element, the first output of the power source is connected to the input of the adaptive processor, the second output is connected to the input of the amplifier system, the third output is connected to the pathogen input to the information inputs of the adaptive processor, namely, to the information inputs of the control vector generation unit and the interference vector generation unit, included av of each of the K blocks of the formation of the vector of weighting coefficients, signals are received from an external source, the output of the control vector generation unit is connected to the input of the multiplier, N outputs of the interference vector generation unit are connected to N inputs of the covariance matrix generation unit of the interference signals, N outputs of which are connected to N inputs block reversal of the covariance matrix of interfering signals, N outputs of the reversal block of the covariance matrix of interfering signals are connected to the inputs of the multiplier, the output is multiplied An amplifier, which is the output of each of the K blocks for generating the vector of weight coefficients, is connected to the input of the approximation block of the vector of weight coefficients, the output of which is the control output of the adaptive processor and connected to the control input of each of the N blocks of complex signal weighting.

A comparative analysis of the claimed device and the prototype device shows that the claimed device is different in that:

- Introduced modulator, exciter, power source, power distribution system, digital-to-analog converters and amplifier system;

- Changed the relationship between the elements;

- the block of approximation of the vector of weight coefficients is introduced into the adaptive processor;

- a control vector forming unit and a jamming vector generating unit are introduced into the weighting vector forming unit.

The combination of distinguishing features of the proposed transmitting adaptive antenna array from the available literature is unknown, therefore, it meets the criteria of the invention of "novelty."

An analysis of the known technical solutions (analogues) in the studied area and adjacent areas allows us to conclude that the elements introduced in the indicated population are unknown, and their introduction into the transmitting adaptive antenna array in the indicated manner and with the indicated connections allows us to provide it with a new property: transmission of useful broadband signal in conditions of ensuring radio concealment, electromagnetic compatibility and electromagnetic ecology. In general, this ensures the claimed solution meets the criterion of "inventive step".

In FIG. 1 is a structural diagram of a transmitting adaptive antenna array.

In FIG. 2 shows a block diagram of an adaptive processor.

In FIG. 3 is a structural diagram of a weighting unit.

In FIG. 4 shows the directivity pattern of the transmitting antenna array at a frequency ϕ ₁ .

In FIG. 5 shows the radiation pattern of the transmitting antenna array at a frequency ϕ ₂ .

Figure 6 presents a variant of the approximation of the real part of the frequency-dependent vector of weighting coefficients for the 17 channel control antenna array piecewise linear function at K = 16. Moreover, curve 1 represents the real part of the optimal frequency-dependent vector of weights for 17 antenna control channel channels, and curve 2 - the real part of the quasi-optimal (approximated) frequency-dependent vector of weights.

In FIG. 7 shows a variant of the approximation of the imaginary part of the frequency-dependent vector of weighting coefficients for the 17 channel control antenna array piecewise linear function at K = 16. Moreover, curve 1 represents the imaginary part of the optimal frequency-dependent vector of weights for 17 antenna control channel, and curve 2 - the imaginary part of the quasi-optimal (approximated) frequency-dependent vector of weights.

The transmitting adaptive antenna array (Fig. 1) includes antenna elements 1 forming an N-element antenna array and connected to the outputs of the amplifier system 2, N digital-to-analog converters 3 connected to the inputs of the amplifier system 2 and the outputs of N blocks 5 of the complex signal weighing, an adaptive processor 4, the output of which is connected to the inputs of each of the N blocks 5 of complex signal weighting, a power distribution system 6, N outputs of which are connected to the inputs of N blocks 5 of the complex signal weighting. The outputs of the power source 7 are connected to the inputs of the adaptive processor 4, the system of amplifiers 2 and the pathogen 8. The control output of the modulator 9 is connected to the input of the pathogen 8, the information output of the modulator 9 is connected to the information input of each of the N blocks 5 of the complex signal weighting. The input of the modulator 9 is connected to a source of information.

The adaptive processor 4 (Fig. 2) consists of a set of K blocks 10 forming the vector of weights, the information inputs of which are connected to an external source, and block 11 approximating the vector of weights, the inputs of which are connected to each of the K blocks 10 of forming the vector of weights, and the output of which is the control output of the adaptive processor.

Each of K blocks 10 of the formation of the vector of weight coefficients (Fig. 3) consists of a block 12 of the formation of the control vector, the information input of which is connected to an external source, and the output with the input of the multiplier 16, block 13 of the formation of the interference vector, the information input of which is also connected to the external source, and N outputs, according to the number of elements of the antenna array, are connected to N inputs of block 14 of the formation of the covariance matrix of the interference signals. The N outputs of the covariance matrix of interference signals generating unit 14 are connected to the N inputs of the covariance matrix of interference signals processing unit 15, the outputs of which are connected to the inputs of the multiplier 16. The output of the multiplier 16 is the output of the weighting vector generation unit 10.

Before considering the functioning of the proposed transmitting adaptive antenna array, we carry out a theoretical justification of the transmission mode of the broadband useful signals implemented in the proposed device, while ensuring radio concealment, electromagnetic compatibility of electronic equipment and electromagnetic ecology.

Consider an N-element antenna array with known radiating aperture geometry, transmitting a useful broadband signal from the θ ₀ , ϕ ₀ direction and generating a “zero” radiation pattern (LH) of the antenna array in the directions θ _l , ϕ _l (l = 1, ..., L). It is required to determine and implement a set of frequency-dependent weighting coefficients in the channels of the transmitting adaptive antenna array, which ensure the formation of “zeros” of radiation paths in the required frequency ranges and directions.

Based on the formulation of the criterion for the optimal processing of a broadband signal to the maximum SINR [6], we formulate a similar criterion for a transmitting adaptive antenna array:

where R _ss (ω) ~ frequency-dependent covariance matrix of the useful signal;

R _nn (ω) is the frequency-dependent covariance matrix of interference signals;

W (ω) is the frequency-dependent vector of weighting coefficients;

ω ₁ , ω ₂ ~ determine the frequency band in which the useful signal is transmitted;

T, * - symbols of transpose and complex conjugation operations, respectively.

The integral (1) takes the maximum value when the integrand is the maximum for each frequency. This allows us to represent the optimal frequency dependence of the weight coefficients in the form [6]:

- управляющий вектор, обеспечивающий построение ДН в состоянии покоя.Where

- the control vector, which ensures the construction of DNs at rest.

ε ₀ , μ ₀ are the electric and magnetic constant of free space, respectively;

θ ₀ , ϕ ₀ - the direction of transmission of the useful broadband signal;

x _n , y _n ~ coordinates of the n-th element of the antenna array.

The frequency-dependent covariance matrix of interfering signals for an arbitrary number of interfering signals is determined by a ratio of the form:

where σ ² is the thermal noise power of the antenna array;

P is the power of the l-th interference signal, l = 1, ..., L;

- помеховый вектор-столбец, элементами которого являются комплексные сомножители, учитывающие фазовый набег на каждом элементе антенной решетки.

- an interference column vector whose elements are complex factors that take into account the phase incursion on each element of the antenna array.

Then the inverse frequency-dependent covariance matrix has the form:

In relation (4), all terms are known except frequency-dependent coefficients α _lp (ω), which can be found from expressions (3) and (4) from the condition

Thus, the expression for the optimal frequency-dependent vector of weights can be written in the form

However, it is technically impossible to precisely implement this dependence. Therefore, it is proposed to ensure the exact implementation of the values of the vector of weighting coefficients in the frequency band of the useful signal for a limited number K of frequencies from a given frequency interval. Between these frequencies, the values of the weighting coefficients can be approximated by a rather simple dependence, for example, by a piecewise constant function or piecewise linear. The choice of the number of frequencies K is determined taking into account conflicting requirements, for example:

- an increase in the number of frequencies K, for which the exact implementation of the values of the weight coefficients is ensured, leads to a more accurate formation of the “zeros” of the ND of the transmitting adaptive antenna array in the required directions;

- an increase in the number of frequencies K causes a sharp complication of the antenna.

The proposed transmitting adaptive antenna array operates as follows.

The information input of the modulator 9 receives a signal from a source of information, which must be transmitted to the subscriber. The modulator 9 modulates the signal according to a certain law and transmits it to the information input of each of the / U units 5 of the complex signal weighting. Also, the modulator 9 provides a control action to the pathogen 8, which begins to transfer energy from the power source 7 to the input of the power distribution system 6. The power distribution system 6 distributes energy to all N control channels of the transmitting adaptive antenna array. The information input of the adaptive processor 4, namely, for each block 12 of the formation of the control vector included in each of the K blocks 10 of the formation of the vector of weight coefficients, receives operational information about the direction of transmission of the useful broadband signal θ ₀ , ϕ ₀ and the frequency of the component ω _k , on which the day will be formed. The information input of each block 13 of the formation of the interference vector, which is part of each of the K blocks 10 of the formation of the vector of weight coefficients, receives operational information about the forbidden frequencies and directions of radiation. Also, the adaptive processor 4 receives a signal from a power source 7 for its energy supply. The adaptive processor 4 generates a control signal in the form of a frequency-dependent vector of weighting coefficients for each of the N channels of the transmitting adaptive antenna array and transmits it to the corresponding unit 5 of the complex signal weighting. The signals from unit 5 of the integrated signal weighting, corresponding to the currently required shape of the ND of the transmitting adaptive antenna array, are fed to the corresponding digital-to-analog converters 3, where they are converted to analog form. Further, the signals through the amplifier system 2, which receives energy from the power source 7, are fed to the elements of the antenna array 1 and are radiated in the required directions.

Let us consider in more detail the functioning of the adaptive processor 4, as well as one of the K blocks 10 of the formation of the vector of weight coefficients included in it. The information input of the control vector generating unit 12, which is part of the weighting vector forming unit 10, receives operational information from an external source about the direction and frequency of the radiation component of the useful broadband signal. In block 12 of the formation of the control vector, the vector S ₀ (ω _k ) is generated, which ensures the construction of the ND of the transmitting adaptive antenna array at rest for a given frequency component, which is fed to the input of the multiplier 16. At the information input of block 13 of the formation of the interference vector included block 10 of the formation of the vector of weight coefficients, operational information is received about the forbidden frequencies and directions of radiation, that is, information about at what frequencies and in which directions the shadow grid should not emit. This is necessary to ensure radio concealment, electromagnetic compatibility of electronic equipment and electromagnetic ecology. In the block 13 of the formation of the interference vector, a “conditional” interference vector is generated that simulates the interference signal emitted from a certain direction with a certain power at a certain frequency, taking into account phase incursions for each element of the antenna array. The signals from the N outputs of the jamming vector generating unit 13 are fed to the inputs of the covariance matrix of the jamming signals generating unit 14, from where they are fed to the inputs of the covariance matrix of the jamming signals processing unit 15, and then to the multiplier 16, where the vector of weighting coefficients is generated for one of the K frequencies. Each of the blocks 15, providing inversion of the covariance matrix of interfering signals at the corresponding frequency, implements an iterative inversion algorithm based on the “bordering” method described for example in [7, 8]. Matrix multiplication operations are implemented using typical elements of signal multiplication and have no fundamental difficulties. The output of the multiplier 16 is the output of the block 10 of the formation of the vector of weights. Next, the signals from each of the K blocks of the formation of the vector of weights corresponding to the vector of weights for one of the K frequencies of the spectrum of the transmitted useful broadband signal are fed to the block 11 approximation of the vector of weights, where the approximation of the vector of weights for each control channel of the antenna array in frequency for K samples (Fig. 6, 7). Next, the signal corresponding to the frequency-dependent vector of weighting coefficients for the corresponding control channel of the antenna array is fed to the corresponding control input of the complex signal weighting unit 5.

To study the emerging patterns, we consider a 10 × 10 antenna array (N = 100), the elements of which are arranged with a step of 0.5λ (λ is the wavelength corresponding to the average frequency of the useful signal range). The radiation direction of the useful signal is θ ₀ = 0 °, ϕ ₀ = 0 ° with the base B = 200, and in the direction θ ₁ = 30 ° ... 54 °, ϕ ₁ = 0 ° at the frequency ω _{2, the} antenna array should not emit (Fig. 5). This information from an external source is quickly fed to blocks 12 and 13 of block 10 of the formation of the vector of weight coefficients.

And in FIG. Figure 4 shows that at a frequency ω _x in the direction θ = 30 ° ... 54 °, ϕ ₁ = 0 °, the transmitting antenna array emits, since no radio reconnaissance is performed at this frequency.

The electromagnetic compatibility of electronic equipment and electromagnetic ecology are likewise ensured.

As the research results show, an increase in the number of K intervals leads, on the one hand, to an increase in the accuracy of reconstruction of broadband signals in the presence of interference, and, on the other hand, to a sharp complication of the antenna.

The transmitting adaptive antenna array can be implemented on a modern element base. The implementation of the entered blocks is straightforward.

The foregoing confirms compliance with the criterion of "industrial applicability" of the proposed technical solution.

Thus, the introduction of a modulator, pathogen, power source, power distribution system, digital-to-analog converters and amplifier system into the adaptive processor - the approximation unit of the vector of weighting coefficients, and into the generation unit of the vector of weighting coefficients - the formation of the control vector and the block of formation of the interference vector allows for the transmission of broadband signals in the necessary directions under conditions of ensuring radio concealment, electromagnetic compatibility of radio electronic x means and electromagnetic ecology.

Literature

1. Monzingo R.A., Miller T.U. Adaptive Antenna Arrays: Introduction to Theory: Per. from English - M .: Radio and communications, 1986. - 448 p.

2. Copyright certificate 1506569. Device for receiving broadband signals with an adaptive antenna array / V.I. Zhuravlev, G.O. Bock - Bulletin of inventions No. 33, 06/25/1987 - H04L 7/02.

3. Copyright certificate 1548820. Adaptive antenna array / L.A. Marchuk, V.V. Popovsky, V.I. Evdokimov S.M. Krymov, I.V. Sergeev. - Bulletin of inventions No. 9, 03/07/1990, -H01Q 21/00.

4. Patent 2099838 (RF). Adaptive antenna array / A.V. Kolinko, V.F. Komarovich, Marchuk L.A., Savelyev A.N. - Publ. 12/20/97 - H01Q 21/00.

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Claims (1)

A transmitting adaptive antenna array containing N antenna elements, N blocks of complex signal weighting, an adaptive processor made of a set of K weighting units, characterized in that an additional amplifier system, N digital-to-analog converters, a power distribution system, a power source, exciter, modulator, an adaptive processor additionally introduces a block of approximation of the vector of weight coefficients, and in each of K blocks of formation of the vector of weight coefficients of cents, a control vector generation unit and an interference vector generation unit are additionally introduced, the modulator input being connected to the information source, the modulator controlling output connected to the exciter input, the modulator information output connected to the information input of each of N complex signal weighting units, the exciter output through the distribution system power is connected to the input of each of the N blocks of complex signal weighing, the output of each of the N blocks of complex signal weighing in through a digital-to-analog converter and amplifier system connected to the input of the corresponding antenna element, the first output of the power source is connected to the input of the adaptive processor, the second output is connected to the input of the amplifier system, the third output is connected to the input of the pathogen, to the information inputs of the adaptive processor, namely information inputs of the control vector generation unit and the interference vector generation unit, which are part of each of the K weighting coefficient vector generation units, post the signals from an external source are falling, the output of the control vector generation unit is connected to the input of the multiplier, N outputs of the interference vector generation unit are connected to N inputs of the covariance matrix of interference signals, the N outputs of which are connected to N inputs of the covariance matrix of interference signals, N outputs of the block the inverse of the covariance matrix of the interference signals are connected to the inputs of the multiplier, the output of the multiplier, which is the output of each of the K blocks s coefficients, is connected to the input of weight vector approximation coefficients, whose output is the control output of the adaptive processor and is connected to a control input of each of N blocks of complex weighting signals.

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