RU2000661C1 - Complex signal receiver - Google Patents

Abstract

Usage: radio engineering, in particular for receiving complex signals under conditions of lumped interference. Summary of the invention 1 device for receiving complex signals contains II-IL antennas, 2g2t beam-forming blocks, extreme regulators 3i-3m, frequency channels 4i 4m, adders 5i- 5m output adder 6, Olok 7 search, tracking and demodulation of a complex signal, shaper 8 borders of the adaptation sector, generator 9 pulses, element OR 10, pulse shaper 11 initial setup and synchronization unit 12, The invention ox is to increase the noise immunity during reception of the multi-directional pattern. 2 s.p. f-ly, 9 ill.

Description

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The invention relates to radio engineering and can be used to receive complex signals under conditions of exposure to concentrated interference,

Multichannel receivers of complex signals are known, containing parallel frequency channels with adjacent characteristics, in which the weighting of the input mixture of signal and interference is carried out. The output signals of the channels are summed, and then the sum signal is demodulated.

However, this device has a low noise immunity of reception in the case when most of the channels are affected by narrowband interference or in the presence of wideband interference.

The closest in technical essence to the proposed is a device for receiving complex signals containing N frequency channels, divided into m groups of N / m channels in each group, the inputs of which are combined and connected to the corresponding antennas. The outputs of the indicators of the interference level of the channels are connected to the inputs of the minimum selection unit, the output of which is connected to the combined inputs of the multipliers. The signal outputs of the channels are connected to the inputs of the adders to N / m inputs, the outputs of which are connected to the input of the adder to m inputs. The adder output to m inputs is connected to the input of the complex signal demodulator. The outputs of adders to N / m inputs through the corresponding multiplier are connected to the inputs of extreme controllers, the outputs of which are connected to the corresponding antenna systems.

However, with multi-lobe (2 lobes and more) antenna patterns, if the zeros of such radiation patterns are oriented towards interference and the direction of arrival of the useful signal is unknown, some of the radiation patterns will be oriented to the useful signal with petals having phase 0, while the other part of the antenna patterns will be focused on the signal with petals having a phase jr. This leads to a violation of the phase structure of the received complex signal and, as a result, to a decrease in the noise immunity of its reception.

The purpose of the invention is to increase the noise immunity of complex signal reception with a multi-lobe antenna pattern.

The goal is achieved in that a device for receiving complex signals containing antennas, m groups of channels, each of which includes a beamforming

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a block, the output of which is connected to the inputs of N / m frequency channels, the outputs of the signal of the interference level of which are connected to the inputs of the adder, and an extreme controller, the output of which is connected to the control input of the beam-forming block, as well as a series-connected output adder and a search, tracking, and complex signal demodulation, a pulse generator, an adaption sector boundary shaper, and an initial setting pulse shaper, an OR element, a synchronization block, and a block output are introduced synchronization is connected to the inputs of the trigger pulse of the extreme regulators of m channel groups, the clock inputs of the extreme regulators of m channel groups are interconnected, with the output of the pulse generator and with the other input of the synchronization unit, the additional output of the complex signal search, tracking and demodulation unit is connected to another the input of the OR element and with the control input of the driver of the borders of the adaptation sector, the input of the initial setting of which is connected to the output of the driver of the pulse of the initial installation, the outputs of the lower and The borders of the adaptation sector boundaries The driver of the adaptation sector boundaries is connected to the corresponding extreme inputs. controllers of all m groups of channels, and the signal outputs of N frequency channels are connected to the corresponding inputs of the output adder, and in each of m groups of channels the corresponding inputs of the beam-forming unit are interconnected and with the outputs of the corresponding antennas, and the output of the adder is connected to the control input of the extreme regulator Torah.

Figure 1 is a structural electrical diagram of a device for receiving complex signals; figure 2 is a structural electrical diagram of a beam-forming unit; Fig. 3 - radiation patterns of beam-forming blocks; figure 4 is a structural electrical diagram of the driver of the boundaries of the adaptation sector; 5 is a structural electric circuit of an extreme controller; figure 6 - structural electrical circuit of the synchronization unit; Fig. 7 is a structural electrical diagram of an initial setting pulse shaper; on Fig - frequency characteristics of the channels and interference spectra at different stages of adaptation; Fig. 9 is an example of a spatial arrangement of a signal and interference.

A device for receiving complex signals contains antennas 1-1 ... 1-L, diagram-forming blocks (DB) 2-1 ... 2-t, extreme regulators 3-1.,. 3-t, frequency channels 4 -1 ... 4-N, adders for N / m inputs 5-1 ... 5-GP, output adder 6, block 7 search, tracking and demodulation of a complex signal (BPSD), shaper 8 borders of the adaptation sector, generator pulses 9, the element OR 10, the driver 11 of the pulse of the initial installation, synchronization unit 12.

The device operates as follows.

Reception is carried out on antennas 1-1 ... 1-N. From the output of each antenna, the signal is fed to the combined corresponding signal inputs of DB 2-1 ... 2-t. As a result of the weighted summation of the input signals at the outputs of the DB 2-1 ... 2-t, independently oriented radiation patterns are formed. From the output of each DB 2-1 ... 2-t signal is fed to the combined inputs of the corresponding group of channels 4-1 ... 4-N. The amplitude-frequency characteristics of the channels are adjacent to one another, overlapping the spectrum of the received complex signal. In the channels of the device, the total signal and interference levels are determined, and the mixture of signal and interference is weighed inversely with these levels. At the outputs of the adders 5-1 ... 5-gp, signals proportional to the sum of the levels in the corresponding channel groups appear.

Extreme 3-1 ... 3-t regulators orient the maxima of the radiation patterns of the corresponding DBs 2-1 ... 2-t within the adaptation sector 1Ке so that the signal levels at the outputs of the corresponding adders 5-1 ... 5-t were minimal. In this case, using DB 2-1 ... 2-t, the best suppression of interference falling into the bandwidth of the corresponding group of channels is provided. The size of the adaptation sector Ф0 does not exceed the aperture of the largest lobe of radiation patterns at the outputs of DB 2-1 ... 2-t. The output signals of all channels are summed on the adder 6 and fed to the combined inputs of the BPSD 7.

If no signal is detected, then BPSD 7 generates a pulse that rotates the adaptation sector by an amount by shifting the boundaries of the adaptation sector at the output of device 8. The value does not exceed the difference between the aperture of the largest lobe of the radiation pattern at the outputs of DB 2-1, .. 2- t and the size of the adaptation sector H 0.

At the same time, the pulse from the output of the BPS / 7 through the OR element 10 and the synphonization block 12 triggers the extreme 3-1 ... 3-ts, which orient the 5 maxima of the radiation pattern corresponding to the DB 2-1 ... 2-t within the limits of the sector H; 0, turned back by lPi so that the best suppression of interference falling into the passband is ensured

0 of the corresponding channel group The adaptation sector is rotated until a signal is detected

If a signal is detected, then the pulse on

5, the output of the BPSD 7 is not formed. In this case, the BPSD monitors the complex signal and demodulates it.

The initial setting pulse generator 11 is intended to be set to the initial position of the device 8 for turning on the power and to start through the OR element 10 and the synchronization unit 12 of the extreme regulators 3-1, .. 3-t, which are oriented optimal t DB

5 2-1 .2-m D within the first adaptation sector The structure of the DB 2-1 ... 2-t depends on the number and type of antennas used. In particular, if two vertical orthogonal frames (L0 2) having eight-type radiation patterns are used as antennas.

The DB contains (see Fig. 2) controlled attenuators 13 and 14, an inverter 15, an adder 16, a switched nat phase shifter 17.

5 The control input of the DB is digital. Moreover, the lower bits of the DB control code are connected by the combined inputs of the inverter 15 and the control inputs of the attenuator 13, and the high-order bit of the control code

0 dB is connected to the control input of the phase shifter 17. The output of the inverter 15 is connected to the control input of the attenuator 14. The attenuators 13 and 14 are of the same type, therefore, due to the inverter 15 changing the control code, the attenuation of one attenuator increases and the attenuation of the other attenuator increases. When the control code changes from 0 to the maximum number Q, a rotation occurs

0 of the resulting radiation pattern at 180 ° with a step Du 180 ° / Q.

By choosing the control code value in a certain way, you can arbitrarily orient the resulting diagram

5 directivity at the output of the DB. For illustration, in Fig. 3, the solid line and the dotted line show diagrams of the first and second antennas L-1, L-2, the outputs of which are connected respectively to the first and second inputs of the DB (see Fig. 2). Force numbers show the phase values of the various lobes of the radiation patterns.

If the transfer coefficient of the attenuator 13 is 1, the phase shift of the phase shifter 17 is 0 °, and the transfer coefficient of the attenuator 14 is 0, then the radiation pattern at the output of the DB will be in the form of a solid line in FIG. If the transfer coefficients of the attenuators 13 and 14 are equal to 0 and 1, respectively, then the radiation pattern at the output of the DB will look like a dashed line in FIG. If the coefficients of the attenuators 13 and 14 are 0.7, and the phase shift of the phase shifter 17 is 0 °. then the resulting radiation pattern at the output of the DB is shown by dots in FIG. If we now make the phase shift of the phase shifter 17 equal, then this will lead to a rotation of the resulting radiation pattern by 90 °,

Shaper 8 boundaries of the adaptation sector (see figure 4) contains: digital adders 18 and 19, register 20, digital comparator 21, pulse counter 22, OR circuit 23.

P, Z, K are digital codes that respectively specify the sizes of the adaptation sector% the value of step H by which the adaptation sector is rotated, as well as the number of rotation steps of the adaptation sector.

The combined input of the register entry 20 and the counting input of the counter 22 are the control input of the adaption sector boundary generator 8. The benefit of the counter 22 through the comparator 21 and the OR circuit 23 is connected to the inputs of the initial installation of the register 20 and the counter 22. A code K is set to the other input of the comparator 21, which sets the maximum number of rotation steps of the adaptation sector. The output of the register 20 is connected to the first inputs of the adders 18 and 19, and also is the output of the device 8, which sets the code of the lower boundary of the adaptation sector. To the other inputs of the adders 18 and 19, codes P and Z are entered, respectively. The output of the adder 18 is the output of the device 8, specifying the code of the upper boundary of the adaptation sector. The output of the adder 19 is connected to the input of the register 20,

Shaper 8 boundaries of the adaptation sector works as follows. When you turn on the power supply to the inputs of the initial installation of the register 20 and the pulse counter 22 through the circuit OR 23, a pulse is received from the external circuit, which sets the outputs of the register 20 and the counter to zero. The value of the code of the lower boundary of the adaptation sector at the output of the device 8 will be is 0, and the upper bound code value will be R.

Upon receipt of the first clock pulse at the input of the register register 20, the number Z will be written into it. This number will be the value of the code of the lower boundary of the adaptation sector at the output of device 8. The value of the code of the upper boundary will be equal to Zf P. Upon receipt of the first clock pulse the input of the register register 20 of the codes of the lower and upper boundaries of the adaptation sector at the output of the device 8 will be equal to IZ and IZ + P, respectively.

When the Kth clock pulse arrives at the input of the device 8, a digital code will appear at the output of the counter 22, the value of which is K. In this case, a pulse will appear at the output of the comparator 21, which, through the OR 23 circuit, will go to the inputs of the initial setup of the register 20 and the counter 22, setting their outputs to the zero state. Subsequently, when clock pulses arrive at the input of the device 8, the code values at its outputs will be periodically repeated.

The extreme controller (see Fig. 5) contains the first 24, second 25 and third 35 registers; the first 26 and second 37 comparators; the first 27 and second 36 switches; the first 28, second 29 and third 34 schemes OR; counter 30 pulses with parallel recording; inverter 31, single vibrators 32 and 33; analog-to-digital converter 38 (ADC); clock input A; input B code of the lower boundary of the adaptation sector; input into the code of the upper boundary of the adaptation sector; input G start pulses; control input D; exit E.

When the supply voltage is turned on, input G receives a pulse that writes to the counter 30 and register 35 of the code of the lower boundary of the adaptation sector, and also writes to the registers 24 and 25 of the output code of the ADC 38. At the same time, the output of the comparator 37 will have a signal that allows serial pulse count by the counter 30, as well as connecting the output of the switch 36 to the output of the pulse counter 30. The comparator 26 generates a logical O voltage at its output if the signal at the output of the second register 25 is greater than or equal to the signal at the output of the first register 24. the input of the switch 27 is connected to its first output and the first pulse at input A records the signal from the output of the ADC 38 in the first register 24. If this signal is larger than the signal recorded previously in the register 25, then the state of the switch 27 will not change a clock pulse will record the output of the ADC 38 in the first

register 24. If the signal recorded in register 24 turns out to be less than the signal recorded in register 25, then the output of comparator 26 will generate a logical 1 voltage. In this case, the input of switch 27 will be connected to its second output, and the next clock pulse will record ADC output signal 38 is already in the second register 25.

A change in the output signal of the comparator 26 will occur each time a smaller number is recorded in one of the registers 24 or 25 than is recorded in the other register. Moreover, each time a smaller number appears, a control code DB 2-1, .. 2t is recorded in the register 35, at which this number appears. The code is written to the register 35 using pulses generated by single vibrators 32 or 33 along the leading or trailing edges of the signal at the output of the comparator 26, respectively.

After the code of the signal at the output of the counter 30 becomes equal to the code of the upper boundary of the adaptation sector at output B, a signal appears at the output of the comparator 37 that prohibits the sequential counting of pulses by the counter 30 and connects the output of the switch 36 to the output of the comparator 35, into which the DOS control code is written at which the output of the ADC 38 was the minimum signal. Moreover, this state will be maintained until another pulse arrives at input G.

The synchronization unit 12 (see Fig.6) contains: a single vibrator 39; Scheme AND 40.

On the leading edge of the incoming pulse, a single-shot 39 generates a pulse at its output, the duration of which is not less than the period of the pulses from the output of the generator 9. In this case, one or several (which is not important) pulses that coincide in time with the pulses occur at the output of the I 40 circuit at the output of the generator 9. It is desirable that the duration of the pulses at the output of the single-vibrator 39 is approximately equal to the period of the pulses from the output of the generator 9. In this case, at the output of the synchronization block no more than two pulses, which allows to reduce the adaptation time of the extreme regulators 3- 1..3-GP.

The pulse generator 11 of the initial installation (see Fig. 7) contains a power source (Ep), a resistor 41, a capacitor 42, a one-shot 43.

When the power supply En is turned on, the capacitor 42 is charged through the resistor 41. When the voltage on the capacitor 42 reaches the threshold of operation of the single-shot 43, a rectangular pulse is generated at the output of the last one.

Assume that there are four parallel frequency channels with adjacent frequency characteristics on the receiving side 5 (see Fig. 8). Four tonal noises are present in the reception band (vertical lines in FIG. 8). The level of narrowband interference at the receiving side is much higher than the level of the useful signal and noise. The direction of the desired signal and interference is unknown. The signal spectrum and atmospheric noise are uniform. Charts

The 5 directions of the antennas are two-lobed and have the shape of a figure eight.

Sources of interference P1 ..... P4, the useful signal C and the receiver Pr are placed in space as shown in Fig.9.

0 The number of DBs and frequency channels is four. The eight-type radiation pattern has two lobes of the same magnitude, the aperture of each of which is 180 °. Suppose that the adaptation sector 1Р0 is 90 ° and the rotation of the adaptation sector is 90 °. In this case, the zeros of the radiation patterns of DB 2-1 ... 2-t are located alternately in I (resp. III), then in II (resp. V) quadrants

0 (see Fig. 9).

Assume first that the maxima of the radiation patterns of DB 2-1 ... 2-t are located in and III quadrants. In this case, not affected by narrowband interference

5 will only be the second frequency channel 4-2. The remaining frequency channels 4-1, 4-3. 4-4 will be hit by narrowband interference, as DB 2-1 and 2-4 do not have the ability to form zeros of radiation patterns in

0 and ill quadrants in which narrow-band interference is located, affecting frequency channels 4-1, 4-3 and 4-4.

Thus, the total spectrum of the signal at the output of the frequency channels will be

5 is limited by the bandwidth of the second channel (see FIG.

At a high level of the input signal, it will be detected, rotation of the radiation patterns of DB 2-1 ... 2-t will not occur. The broadband signal and its demodulation will be monitored.

If the input signal is low, signal detection will not occur. About 5 °, the adaptation adaptation of DB 2-1 ... 2-t by 90 ° will occur. In this case, the maxima of the directivity patterns of the spatial channels will be located in II and IV quadrants. In this case, the zeros of the directivity patterns

B 2-1 and 2-4 will be focused on interference li and P / respectively. The zero radiation pattern of DB 2-3 will be oriented towards the largest of the interference Pg or Pz. The maximum of the directivity pattern of DB 2-2 at the maximum level of the useful signal will be randomly oriented within the adaptation sector. With this orientation of the directional patterns of the DB in the reception band, one of the narrow-band interference P2 or Pz will remain. the total spectrum of the signal at the output of the frequency channels will be limited by the bandwidth of the first, second, and fourth channels (see Fig. 10). Since the useful signal is in the adaptation sector, in which we expected, the lobes of the radiation pattern of DB 2-1 ... 2-4 with the same phase value will be directed at it. The signal-to-noise ratio at the output of the BPSD in comparison with the previous case will increase in VTpas, i.e. 4.8 dB.

Thus, at a low level of the useful signal, all four interferences are suppressed, while only one section of the spectrum affected by the interference is rejected, and there are no phase-frequency distortions of the useful signal.

Claims (3)

SUMMARY OF THE INVENTION 1. A device for receiving complex signals, comprising m groups of channels, s each of which includes a series-connected antenna and a beam-forming unit, the output of which is connected to the inputs of the N / m frequency channels, the outputs of the signal of the interference level of which are connected to the corresponding adder inputs, and an extreme controller, the output of which is connected to the control input of the beam-forming unit, as well as the output adder and the search, tracking, and demodulating complex signal unit la, characterized in that, in order to increase the noise immunity of the reception with a multi-lobe radiation pattern, a pulse generator, an adaption sector edge shaper and a serial setup pulse shaper, an OR element, a synchronization unit are introduced, while the output of the synchronization block is connected to the inputs of the extreme trigger pulse controllers of m channel groups, clock inputs of extreme controllers of m channel groups are interconnected, with the output of the pulse generator and with another input m sync block, an additional output block search, tracking and demodulating the complex the signal is connected to another input of the OR element and to the control input of the driver of the borders of the adaptation sector, the input of the initial installation of which is connected to 5 by the output of the driver of the pulse of the initial installation, the outputs of the lower and upper boundaries of the adaptation sector of the driver of the boundaries of the adaptation sector are connected to the corresponding inputs of extreme 10 controllers of all m channel groups, and the signal outputs of N frequency channels are connected to the corresponding inputs of the output adder, in each of the m groups of channels, the other inputs of the digitizing block are connected to the antennas of other (t-1) channel groups, and the adder output is connected with the control input of the extreme controller. 2. The device according to claim 1, with the exception of - 20 so that the shaper of the boundaries of the sector Adaptation is made in the form of a sequential NOSORDINES pulse counter, a comparator and an OR element, the output of which is connected to the inputs of the initial installation 25 pulse counter and register, the output of which is connected to the inputs of the first and second adders, and the output of the second adder is connected to the input of the register, and the counting input of the pulse counter and the clock input 30 registers are interconnected and are the control input, and the other input of the OR element is the input of the initial setup of the adaption sector boundary generator, the outputs of the lower and upper boundaries of the adaptation sector are the register output and the output of the first adder, respectively. 3. The device according to claim 1, with the exception that the extreme controller is more complete in the form of an analog-to-digital converter (ADC), the output of which is connected to input through the first and second registers. the first comparator, the output of which is connected to the outlets of the inverter, the first odovibrator and the control input of the first switch, the outputs of which are connected respectively to the first inputs of the first and second elements OR, the outputs of which are connected respectively to 50 clock inputs of the first and second registers, the output of the first one-shot is connected to the first input of the third OR element. the second input of which is connected to the inverter output through the second one-shot55, the output of the third OR element is connected to the clock input of the third register, the input of which is connected to the counter output with parallel recording, to the first input of the second comparator and to the first exit of the second switch, to the second input of which the output of the third register, where the ADC input is the control input, and the ADC clock input connected to the input of the first switch is the clock input of the extreme controller, the trigger input is and which are the second inputs of the first, second, and third OR connected to each other and the input of the initial setting of the pulse counter with parallel recording, and the inputs of the lower and upper F 0 the boundaries of the adaptation sector and the extreme controller are respectively the parallel recording input of the pulse counter with parallel recording and the second input of the second comparator, the output of which is connected to the enable input of the sequential counting of the pulse counter with parallel recording and the control input of the second switch, the output of which is the output of an extreme controller. F (rieZ ЈpЈS && pi / Ј.5