RU2779925C1 - Method for the distributed reception of a signal transmitted over a multipath channel, and a system for its implementation - Google Patents

Abstract

FIELD: communication technology.

SUBSTANCE: invention relates to automatic packet radio communication in the decameter range (3-30) MHz. Technical means have been introduced into the device that provide procedures for frequency channel separation, use in the transmission of orthogonal signals together with majority decoding.

EFFECT: increasing the noise immunity of receiving discrete information in the radio lines of the DCM range.

2 cl, 2 dwg

Description

The invention relates to automatic packet radio communication in the decameter (DKM) range (3-30) MHz.

Known analogue - HF (DKM) packet data exchange system [1], which provides the implementation of processes, containing HF on-board stations connected via HF radio channels "Air-to-Earth" with HF ground stations, which in turn are connected to the control center of the mentioned system and with control towers for air traffic control and airlines through the ground communication subsystem. Each HF ground station contains an HF ground station controller, which is connected by control to N HF transmitters connected to N HF transmitting antennas, as well as to N HF air-to-ground receivers connected to a common HF receiving antenna, with information inputs of N modulators a single-tone multi-position phase-shift keyed signal connected to N HF transmitters with information outputs of N air-to-ground demodulators of a single-tone multi-position phase-shift keyed signal. N air-to-ground demodulators are connected to N RF receivers. The RF ground station controller is also connected to a common time signal receiver connected to the common time signal receiving antenna and to an interface device with the terrestrial communication subsystem. Each RF ground station contains at least one additional RF ground-to-ground communication receiver and at least one additional ground-to-ground demodulator of a single-tone multiposition phase-shift keyed signal, the output of which is connected to an additional information input of the RF ground station controller , and the input - to the output of the additional RF receiver "Earth-to-Earth". The information input of the additional RF receiver "Ground-to-Ground" is connected to a common RF receiving antenna, and its control input is connected to the additional control output of the ground station RF controller.

The disadvantages of the analog should include the fact that it does not use majority decoding and diversity reception to improve communication reliability.

A known method of diversity reception using the negative correlation of signal fading in parallel channels [2].

This method is based on a model of radio wave propagation, in which a negative fading correlation may occur at spatially separated receiving points, and assumes the presence of a radiation source, for example, a radio transmitter with a single vertical vibrator, a propagation medium in which one path of wave arrival at the receiving point is direct (" ground wave"), and the other with reflection from a vertical plane, for example, from the ionospheric layer, and at least two radiation receivers, for example, in the form of vertical dipole antennas spaced apart in space at a distance of the order of several wavelengths. The occurrence of negatively correlated signal fading in the receiving elements depends on a number of parameters: the distance of the path, the height of the reflecting layer, and the magnitude of the spatial separation between the receiving antennas.

When organizing radio communications in the DKM range on routes with a length of 500 km or more, the "ground wave" is practically absent. At the same time, experimental data are known that indicate that several signal beams (at least two), reflected from different layers of the ionosphere, arrive at the receiving point [3]. With multipath, in particular with two-beam, propagation of radio waves on paths with a length of 500 km or more, it is possible to create conditions for the occurrence of a negative correlation of signal fading.

This spatial diversity method does not exploit the negative-correlation gate diversity capability, since the addition of all the signals from the diversity receiver elements at once in a coherent or non-coherent manner is applied.

A known method of diversity reception of a signal from a radiation source [4], which consists in placing three receiving elements on a straight line oriented to the radiation source, at a distance greater than the wavelength and a multiple of it from each other and the subsequent optimal summation of the diversity signals, each of the diversity signals is formed as a result of coherent addition of signals from the middle receiving antenna element with each of the extreme receiving antenna elements.

The disadvantage of this method is the lack of frequency diversity and majority decoding to improve communication reliability.

A device for multichannel coherent addition of diversity signals is known [4]. The device contains spatially separated antenna elements, an addition device (cogerator), a decision circuit, as well as a main selection filter in each receiving channel, a normalizing amplifier, an adjustable amplifier and a control device containing a decision circuit, a VIP module meter: an averager and a functional converter connected to rationing scheme for weight coefficients.

The disadvantage of this device is that all reception channels participate in coherent addition, including those in which practically only noise is present, and the signals are significantly attenuated due to fading in these communication channels.

It is also known a device for spatial diversity reception [5]. This device contains three antenna receiving elements located on a straight line oriented to the radiation source, at a distance from each other greater than the wavelength and a multiple of it, two coherent addition units, the inputs of which are connected to the middle and corresponding extreme receiving antenna elements, and the outputs are connected to the block of optimal addition. In this device, the distance between pairs of receiving elements is fixed and only two pairs are used.

The possibility of using the negative correlation of signal fading in the diversity branches in the device is extremely limited.

A complex of means of protecting narrow-band radio communication systems in a complex radio-electronic environment is known [6]. It contains, on the transmitting side of the radio communication system, a message source connected in series, a discrete signal generator, an encoder, a phase generator, a phase modulator, a power amplifier and a transmitting antenna, an initial PM signal generator of the transmitting side, the outputs of which are connected to the corresponding inputs of the original PM signal adder, the adder outputs source FM signals are connected to the corresponding inputs of the encoder.

On the receiving side, the complex contains a receiving antenna connected in series, a microwave amplifier and a phase demodulator, as well as a decision threshold device, the first input of which is connected to the output of the threshold generator, and the output of the decision threshold device is connected to the input of the converter of discrete message signals, from the output of which information is supplied to consumers , a generator of the initial PM signals of the receiving side, a series-connected analog-to-digital signal converter, a signal scaler for compressing the PM video signal packet of the message in time, an impulse noise compensation device, an interpolation device, an amplitude normalizer and a decoder with correlation processing of the PM signal of the message, the outputs of which are connected to the corresponding inputs of the adder of discrete signals, the output of the adder of discrete signals is connected to the second input of the decision threshold device, the outputs of the shaper of the initial FM signals of the receiving side are are connected to the corresponding inputs of the decoder with correlation processing of the PM signal of the message, while the input of the analog-to-digital signal converter is connected to the output of the phase demodulator.

The analogue has the following disadvantages:

- the complex does not use the possibility of frequency division of channels;

- the value of the probability bit P _b =10 ^-4 for the transmission of some priority signals is not enough.

A known method of spatial diversity reception of a signal from a radiation source transmitted over a multipath channel, which by most significant features is taken as a prototype [7]. It consists in placing the receiving antenna elements (positions) on a straight line oriented to the radiation source. Antenna elements are at a distance from each other greater than the wavelength and a multiple of it. On the receiving side, the diversity signals are optimally combined. Moreover, each of the diversity signals is formed as a result of coherent addition of the signal from one receiving antenna element, which is the reference, with the signal of each of the other antenna receiving elements. The reference receiving antenna element is the first receiving antenna element.

The spatial diversity device for receiving a signal from a radiation source transmitted over a multipath channel contains N receiving antenna elements placed on a straight line oriented to the radiation source, at a distance from each other greater than the wavelength and a multiple of it, N-1 coherent addition blocks, one of inputs of the i-th block of coherent addition, where i=1, 2, N-1, is connected to the output of the j-th receiving antenna element, where j=2, 3, N, the block of optimal addition, the inputs of which are connected to the outputs of blocks of coherent addition . The device also contains an additional coherent addition block, the inputs of which are connected to the outputs of the receiving antenna elements, and the output to the additional input of the optimal addition block, made in the form of a majority weight summation block, and the other inputs of the coherent addition blocks are connected to the output of the first receiving antenna element.

The disadvantages of the prototype include:

- diversity is carried out only by the spatial method;

- the method is effective only at one frequency, since the distance between the receiving positions is rigidly tied to the wavelength value;

- the source of radiation in space must be placed on the same line with the receiving antenna elements, which in practice is difficult to accurately combine these objects in the same direction, since the DKM communication is beyond the horizon;

- the amount of transmitted information is limited by one communication channel.

The technical objective of the invention is to increase the noise immunity of receiving discrete information in the radio lines of the DCM range, which is achieved by the fact that additional procedures are introduced into the method of spatial diversity reception in the channels of the DCM range: frequency diversity and the use of orthogonal signals in conjunction with majority decoding.

The specified technical result is achieved by the fact that in the method of diversity reception of a signal transmitted over a multipath channel at a frequency f1, which consists in the optimal addition of diversity signals by receiving antenna elements, each of the diversity signals is formed as a result of coherent addition of the signal from the first receiving antenna element, which is the reference , with the signal of each of the other antenna receiving elements, the reception is carried out by N receiving antenna elements installed at a distance of more than ten wavelengths from each other, while in the radiation source messages are sent in two streams, each of the messages is encoded with its orthogonal code, encoded parcels are combined in each stream, after which the carrier is modulated in the first stream with a frequency f1, in the second - with a newly formed frequency f2, transmitted in parallel to the receiving antenna elements, then the received signals are separated by frequencies, demodulated, the function of mutual correlation of the received signals with known orthogonal codes, restore the transmitted messages, carry out the majority addition of the messages of the same name from different receiving positions, determine their reliability, on the basis of which the threshold is set at the output of the demodulation procedure.

The spatial diversity system for receiving a signal transmitted over a multipath channel, which implements the proposed method, includes a receiving and transmitting part, while the transmitting part contains two parallel chains of blocks designed to work with radio signals of the carrier frequency f1 and f2, respectively, each of which contains a generator of the original orthogonal transmitting side codes, a carrier frequency generator, a series-connected input stage, a message source encoder, a discrete signal adder and a modulator, while the carrier frequency generator is connected to the modulating input of the modulator, and n outputs of the original orthogonal code generator of the transmitting side are connected to n inputs of the message source encoder , the output of each modulator is connected to the corresponding input of the adder, the output of the adder is connected through the transmitter to the transmitting antenna, the output of which is the high-frequency output of the system, and the inputs of the input stages are information inputs of the system, the receiving part contains N spatially separated receiving antenna elements installed at a distance of more than ten wavelengths from each other, 2N blocks of coherent addition, 2N threshold devices, 2N decoders of orthogonal codes, 2N shaper of the initial orthogonal codes of the receiving side, two blocks of the majority weight summation, two additional blocks of coherent addition and two output stages, each receiving antenna element is connected to two parallel chains of blocks designed to work with radio signals of the carrier frequency f1 and f2, respectively, each of which contains a series-connected block of coherent addition, a threshold device, a decoder orthogonal codes, n outputs of which are connected to n inputs of the majority weight summation block, the output of the majority weight summation block is connected to the input of the output stage, and the output of the output stage is the output of the system, while the corresponding inputs of the decoder orthogonal codes are connected to the outputs of the source orthogonal code generator of the receiving side, the control input of the threshold device is connected to the corresponding output of the majority weight summation block, the coherent addition blocks, designed to work with radio signals of one carrier frequency, are sequentially interconnected from the first to the last (Nth ), and the last (Nth) coherent addition block is connected to the corresponding input of the corresponding additional coherent addition block, each of the N receiving antenna elements is connected to the corresponding inputs of the first and second additional coherent addition blocks, the outputs of the first and second additional coherent addition blocks are connected to corresponding to the inputs of the first and second blocks of the majority weight summation, respectively.

In FIG. 1 shows a block diagram of the transmitting part of the radio wave propagation system. In FIG. 2 shows a block diagram of the receiving part of the system that implements the claimed method. The following notations are introduced on the figures:

1 _j - receiving antenna elements (j=1, 2, ... N);

2 _1j , 2 _2j - the first and second blocks of coherent addition;

3 ₁ , 3 ₂ - the first and second blocks of majority weight summation;

4 ₁ , 4 ₂ - the first and second additional blocks of coherent addition;

5 ₁ , 5 ₂ - information inputs of the system for transmitting information on two carrier frequencies f ₁ and f ₂ respectively;

6 ₁ , 6 ₂ - first and second input stages;

7 ₁ , 7 ₂ - the first and second encoders of the message source;

8 ₁ , 8 ₂ - generators of the original orthogonal codes of the transmitting side;

9_one, 9₂ - adders of discrete signals of the carrier frequency f_one and f₂ respectively;

10 ₁ , 10 ₂ - the first and second modulators of the carrier frequency f ₁ and f ₂ respectively;

11 ₁ , 11 ₂ - the first and second generators of the carrier frequency f ₁ and f ₂ respectively;

12 - summing device;

13 - transmitter;

14 - transmitting antenna;

15 _1j , 15 _2j - first and second threshold devices;

16 _1j , 16 _2j - first and second n-channel decoders of orthogonal codes;

17 _1j , 17 _2j - the first and second generators of the original orthogonal codes of the receiving side;

18 ₁ , 18 ₂ - the first and second output stages;

19 ₁ , 19 ₂ - the first and second outputs of the system.

2 ₁₁ -2 _aN and 2 ₁₂ -2 _6N - the first and second blocks of coherent addition for channels of frequency f ₁ and frequency f ₂ respectively.

The first blocks 2 _1j , 4 ₁ , 15 _1j , 16 _1j , 17 _1j are designed to process signals of the carrier frequency f ₁ .

The second blocks 2 _2j , 4 ₂ , 10 ₂ , 11 ₂ , 15 _2j , 16 _2j , 17 _2j are designed to process signals of the carrier frequency f ₂ .

The system according to the claimed method works as follows.

Discrete information in the message source is fed to inputs 5 ₁ and 5 ₂ of the system. Distribution of messages to the inputs 5 ₁ and 5 ₂ carried out to transmit information on two carrier frequencies f ₁ and f ₂ . Depending on the specified mode of operation in the output stages 6 ₁ and 6 ₂ , for example: all system resources are used to transmit only one message to ensure high reliability of information reception, system resources are used to transmit 2n messages - to ensure the transmission of a large amount of information. There may be other modes that are combinations of the two modes mentioned above.

Then the discrete information is fed to the first inputs of the encoders 7 ₁ and 7 ₂ message sources, the second input of which receives the code signal from the generators 8 ₁ and 8 _{2 of} the original orthogonal codes of the transmitting side.

Combining the signals from the outputs of the nodes 7 ₁ and 7 ₂ is carried out using adders 9 ₁ and 9 ₂ . The initial signals are formed in the form of orthogonal elements of the signal system, the autocorrelation function of which has smaller side lobes, for example, among Walsh codes with orthogonality properties [6].

In the adders 9 ₁ and 9 ₂ is the combination in time of the signals and their summation. As a result, packets of parallel assembly are formed from discrete signals, from which packets of the code signal are formed.

In the encoders 7 ₁ and 7 ₂ of the message source, each discrete binary signal is converted by a code signal packet into a signal packet, for example, consisting of discrete signals with the same amplitudes.

The thus formed signal packet in the encoders 7 ₁ and 7 ₂ of the message source can be transmitted in the allocated bandwidth of the system.

From the output of the encoders 7 ₁ and 7 ₂ of the message sources, the signal packets through the adders 9 ₁ and 9 ₂ are fed to the modulators 10 ₁ and 10 ₂ , respectively, the modulating inputs of which are energized from the generators 11 ₁ and 11 _{2 of} the carrier frequency f ₁ and f ₂ , respectively . Then the radio signals with carrier frequency f ₁ and f ₂ are combined in the adder 12, filtered and amplified by power in the transmitter 13 and are emitted into the communication channel using the transmitting antenna 14.

On the receiving side, the radio signals arrive at N antenna elements 1 _j , after which the radio signals of the carrier frequency f ₁ pass through the first blocks of coherent addition 2 _1j connected in series, the threshold device 15 _1j and the decoder 16 _1j of orthogonal codes, n outputs of which are connected to n inputs of the first block 3 ₁ majority weight summation. Carrier frequency radio signals f ₂ pass through serially connected second blocks of coherent addition 2 _2j , threshold device 15 _2j and decoder 16 _2j of orthogonal codes, n outputs of which are connected to n inputs of the second block 3 _{2 of} majority weight summation.

To the corresponding inputs of all the first threshold devices 15 _1j connected to the corresponding outputs of the first block 3 ₁ majority weight summation.

To the corresponding inputs of all the second threshold devices 15 _2j connected to the corresponding outputs of the second block 3 ₂ majority weight summation.

All the first 16 _1j decoders are connected by n inputs to n outputs of the corresponding first 17 _{1j generators} of the initial orthogonal codes of the receiving side.

All second 16 _2j decoders are connected by n inputs to n outputs of the corresponding second 17 _{2j generators} of the initial orthogonal codes of the receiving side.

The first outputs of blocks 3 ₁ and 3 ₂ majority weight summation connected to the inputs of the first 18 ₁ and second 18 ₂ output stages, respectively. The outputs of the first 18 ₁ and second 18 ₂ output stages are the first 19 ₁ and second 19 ₂ output of the system, respectively.

In antenna elements 1 _j separated from each other at a distance of more than 10 wavelengths due to the electromagnetic field, uncorrelated voltages with different phases are induced. The correlation coefficient between the voltages induced in the antenna elements 1 _j depends on the ratio of the amplitudes of the rays and the phase difference between the voltages induced by the rays in the antenna element, the path length, the height of the ionospheric layers, the operating frequency of the channel. Formulas for determining the correlation coefficient are given in the RF patent for the invention No. 2075832 [7].

In one of the options for constructing the system in blocks 2 ₁₁ (2 ₂₁ ) of coherent addition, radio signals with a carrier frequency f ₁ (f ₂ ) are converted to an intermediate frequency, then fed to other 2 _{1 (N-1)} , (2 _{2 (N-1 )} ) blocks of coherent addition. In another version of the system construction in the first blocks 2 ₁₁ (2 ₂₁ ) of coherent addition after demodulation, the video signal packet, for example, is fed to the input of an analog-to-digital converter for conversion and digital processing while maintaining the phase of the radio signals. In this case, an output stage is installed at the output of the analog-to-digital converter, which ensures the transfer of digital data to other 2 _1(N-1) , (2 _2(n-1) ) coherent addition blocks.

From the output of the blocks, a packet of video signals after demodulation for the first version of the system or in digital form for the second version of the system are sent to the threshold device 15 _1j , (15 _2j ) to the control input of which from the first (second) block 3 ₁ (3 ₂ ) of the majority weight summation a constant voltage is applied in the first case or a digital code in the second case. The threshold level changes in blocks 3 (3 ₂ ) of the majority weight summation depending on the results of assessing the reliability of the received information.

From the output of the threshold device 15 _1j , (15 _2j ) data packets are transmitted to the input of the corresponding decoder 16 _1j , (16 _2j ) of orthogonal codes, the other n inputs of which receive n original signals from the n output of the corresponding shaper 17 _1j , (17 _2j ) known source orthogonal codes of the receiving side.

Due to the correlation processing in n channel decoders 16 _1j , (16 _2j ) the spectral densities of interference and noise when multiplied by copies of the original orthogonal signals are expanded. As a result, correlations in the frequency band of each channel, the power of interference and noise are weakened in accordance with the value of the signal base, and the signal-to-noise ratio increases [6, 8, 9].

From the outputs of n channel decoders 16 _1j , discrete signals with a carrier frequency f ₁ are fed to the inputs of the first block 3 _{1 of} the majority weight summation, and from the outputs of n channel decoders 16 _2j discrete signals with a carrier frequency f ₂ are fed to the inputs of the second block 3 _{2 of} the majority weight summation. Blocks of additional coherent addition 4 ₁ (4 ₂ ) and coherent addition 2 _1j (2 _2j ) are designed to operate in the first embodiment of the system at an intermediate frequency and contain controlled phase shifters and a control circuit. For the first version of the system, they can be implemented similarly to the coherent signal combining unit used in the commercially available OTRADA R-692 multichannel radio receiver [7]. For the second embodiment of the system, intermediate frequency radio signals can be converted into discrete ones using high-speed ADCs and their processing is carried out by computing devices.

The majority weight summation blocks 3 ₁ and 3 ₂ operate according to the principle described in [10] and [11]. The scheme of the majority weight summation block contains, for example, a calculator, a synchronization device, a threshold generator, a majority decoder according to the “m out of 2n” criterion, and a signal comparison device that evaluates short blocks of information in the received message, for example, (8-10) characters long at a processing speed of 500 bps. This block length corresponds to the quasi-stationary period of the DCM channel. Based on the results of the reliability assessment, for example, according to the maximum number of accurately received characters of discrete information, a decision is made to assign information to the receiving channel of weight ₀ or ₁ . majority decoding according to the “m out of 2n” criterion, then the noise immunity (reception reliability) can be increased by several orders of magnitude [9].

In this case, channels with the number of errors exceeding a certain value specified using blocks 3 ₁ and 3 ₂ receive weight 0 in nodes 18 ₁ and 18 ₂ and the signals received from them do not participate in further processes. Signals in channels with the number of errors not exceeding the specified value in the threshold device 15 _1j , (15 _2j ), are subject to discrete majority addition in block 3 ₁ or 3 ₂ . Therefore, only reliable information is supplied to the outputs 19 ₁ and 19 ₂ of the system.

Simultaneously there is a coherent addition of the signals of all antenna receiving elements 1 _j in additional blocks 4 ₁ and 4 ₂ coherent addition. The need for this type of summation is due to the fact that in a real situation, when communicating in the DKM range, there is a multipath propagation model, and with it, coherent multichannel summation is more efficient, taking into account the summation in a coherent situation in blocks 3 ₁ and 3 _{2 of} the majority weight summation.

The proposed method and the system that implements it make it possible to determine channels with a minimum probability of erroneous reception at each of the two carrier frequencies and provide increased reception reliability, and, consequently, system noise immunity.

Literature

1. RF patent for invention No. 2286030, publication date 10/20/2006 Bull. No. 29.

2. Andronov I.S. et al., Transmission of discrete messages over parallel channels, Moscow: Soviet radio, 1971, p. 81-88.

3. Malygin V.B. Evaluation of multipath KB signal based on the results of pulsed oblique sounding, Radiotekhnika, v. 37, 1982, N 2, p. 75-77.

4. Author's certificate of the USSR N 196113, published in 1967.

5. Sosnovsky N.S. et al., Coherent addition of diversity signals with preliminary weighting of partial channels. TSS, ser. TR, 1981, no. 10 (29), p. 51.

6. RF patent for invention No. 2720215, publication date 04/28/2020 Bull. No. 13.

7. RF patent for invention No. 2075832, publication date 03/20/1997 (prototype).

8. Varakin L.E. Communication systems with noise-like signals. - M.: Radio and communication, 1985. 384 p.

9. Sklyar, Bernard. Digital communication. Theoretical foundations and practical application. Ed. 2nd, corrected: Per. from English. - M.: Publishing house "William", 2003. 1104 p.

10. Fink L.M. Theory of transmission of discrete messages, Moscow: Soviet radio, 1970, p. 437.

11. Zhukov G.A. Methods for weighted majority processing of DI when receiving via parallel channels. TSS, ser. TPS, 1983, no. 8, p. 74.

Claims (2)

1. The method of diversity reception of a signal transmitted over a multipath channel at a frequency f ₁ , which consists in the optimal addition of signals received by diversity receiving antenna elements, while generating diversity signals by coherently adding the signal from the first receiving antenna element, which is the reference, with the signal of each of the rest of the antenna receiving elements, characterized in that the receiving antenna elements are installed at a distance from each other greater than ten wavelengths, while the information transmitted over the multipath channel is encoded with an orthogonal code, the coded packets are combined and sent along two streams, transmitting them at two carrier frequencies f ₁ and f ₂ , by modulating the carrier frequencies with combined coded packets, the received diversity signals are separated by frequency by demodulation, decode the information by calculating the cross-correlation function of the received signals with orthogonal codes, restore the transmitted messages and the wire yat majority summation of the corresponding messages from different spaced receiving antenna elements, determine their reliability, on the basis of which the value of the demodulation threshold is set. 2. A spatial diversity system for receiving a signal transmitted over a multipath channel, comprising a receiving and transmitting part, while the transmitting part contains the first chain of series-connected input stage, message source encoder, discrete signal adder and modulator, as well as a carrier frequency generator f ₁ , the output of which is connected to the input of the modulator, the receiving part contains N spatially separated receiving antenna elements, characterized in that the second chain of the serially connected input stage, the message source encoder, the adder of discrete signals and the modulator, as well as the carrier frequency generator f ₂ , the output of which is connected to the input of the modulator, as well as the generator of the initial orthogonal codes of the transmitting side, the n outputs of which are connected to the n inputs of the encoder of the message source of each chain, the output of the modulator of each chain is connected to the corresponding input of the adder, the output d which is connected through the transmitter to the transmitting antenna, and in the receiving part, the spaced receiving antenna elements are installed at a distance from each other greater than ten wavelengths, 2N coherent addition units, 2N threshold devices, 2N orthogonal code decoders, 2N generators of the initial orthogonal codes of the receiving side, two blocks of the majority weight summation, two additional blocks of coherent addition and two output stages, while each receiving antenna element is connected to two parallel chains of blocks, designed to work with radio signals of the carrier frequency f ₁ and f ₂ , respectively, each of which contains in series connected coherent addition block, threshold device, orthogonal code decoder, n outputs of which are connected to n inputs of the majority weight summation block, the output of the majority weight summation block is connected to the input of the output stage, and the output of the output stage is the output of the system, while with the corresponding inputs of the orthogonal code decoder are connected to the outputs of the generator of the initial orthogonal codes of the receiving side, the control input of the threshold device is connected to the corresponding output of the majority weight summation block, the coherent addition blocks, designed to work with radio signals of one carrier frequency, are connected in series from the first to the last ( N-th), and the last (Nth) block of coherent addition is connected to the corresponding input of the corresponding additional block of coherent addition, each of the N receiving antenna elements is connected to the corresponding inputs of the first and second additional blocks of coherent addition, the outputs of the first and second additional blocks of coherent addition additions are connected to the corresponding inputs of the first and second blocks of the majority weight summation, respectively.

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