RU2308155C2 - Radio communication line with increased concealment of transferred information - Google Patents

Abstract

FIELD: radio communications, possible use in space and ground communication systems, using noise-like signals.

SUBSTANCE: at transmitting side device features: first and second transmitter decoders, transmitter counter, first and second transmitter keys, transmitter phase inverter, OR circuit of transmitter, at receiving side device features: first and second receiver decoders, receiver counter, first and second receiver keys, receiver phase-inverter, OR circuit of receiver, first and second gates.

EFFECT: increased concealment of information being transferred.

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Description

The proposed device relates to the field of radio communications and can be used in space and ground-based communication systems using noise-like signals (SHPS).

Known communication systems with SHPS, such as N.T. Petrovich, M.K. Razmakhnin "Communication systems with noise-like signals." M .: Sov. Radio, 1969, p. 96, Fig. 40, in which the delay τ is used as a modulated parameter. The noise generator gives a voltage τ (t), the spectrum of which is formed by a filter. The signals τ (t) and τ (t-τ) are added up in the adder and transmitted to the air.

At the receiver, a correlation function is calculated. However, in this device noise immunity is low, because To receive information, it is necessary to establish the presence of a partial maximum of the correlation function, the amplitude of which is two times less than the amplitude of the main maximum.

A digital phase shift keying system is also known. L.E. Varakin "Communication systems with noise-like signals", "P and C", 1985, p. 16, Fig. 1.7, designed to transmit discrete messages. In the transmitter, information is fed to the input of the phase modulator, to the second input of which a phase-shift (FM) signal from the FM signal generator (HFM) is supplied. The operation of the GFM is controlled by a synchronizer, which generates the necessary frequency control signals. The NPS sequence in the form of an FM signal, transmitting information symbols, enters the modulator, in which balanced oscillation modulation is carried out with the carrier frequency of the FM signals. A power amplifier amplifies these oscillations and radiates into the ether through the antenna.

At the receiver, the signal is transferred to an intermediate frequency, amplified, and processed by a matched filter. From the output of the matched filter, the signal is supplied to the synchronizer and the resolver. The synchronizer searches for the FM signal by frequency and time, controls the mode of operation of the solver.

To search for a signal by frequency, the synchronizer rebuilds the local oscillator, because If this device includes a matched filter, then in this device only incoherent reception of orthogonal signals is practically possible, which leads to insufficient noise immunity of receiving information, since higher noise immunity is provided when incoherent reception using opposite signals. In addition, the practical implementation of a matched filter at large signal bases is a difficult technical task.

The closest in technical essence to the claimed object is a device for A. with. No. 300946, taken as a prototype.

Figure 1 shows the functional diagram of the device of the prototype, where the notation is introduced:

1 - generator oscillations of the carrier and clock frequencies (GNST);

2 - shaper orthogonal pseudo-random sequence (FOPP);

3 - pseudo-random sequence generator (GLP);

4 - phasing device;

5, 6 - the first and second multipliers, respectively;

7 - phase shifter 90 °;

8 - phase manipulator;

9 is a diagram of addition;

10, 11 - the third and fourth multipliers, respectively;

12 - shaper orthogonal pseudo-random sequence (FOPP);

13 - generator reference pseudo-random sequence (GOPP);

14 - phasing device;

15 - synchronization device;

16, 17 - the first and second band-pass filters;

18 is a phase detector.

The prototype device contains on the transmitting side: sequentially connected FOPP2, the first multiplier 5, the addition circuit 9, the output of which is the output of the transmitter, connected in series GPP3, the second multiplier 6, the output of which is connected to the second input of the addition circuit 9, as well as GNST1, the first output which is connected to the first inputs of FOPP2 and GPP3, respectively, the second GNTC1 output is connected to the input of the phase shifter by 90 ° 7 and to the first input of the phase modulator 8, the second input of which is information, the output of the phase manipulator a 8 is connected to the second input of the second multiplier 6, and the phase shifter output of 90 ° 7 is connected to the second input of the first multiplier 5, while the second inputs of FOPP2 and GPP3 are connected to the corresponding outputs of the phasing device 4, on the receiving side: phasing device 14 connected in series FOPP12, the third multiplier 10, the first bandpass filter 16, the phase detector 18, the output of which is information, connected in series GOPP13, the fourth multiplier 11, the second bandpass filter 17 whose output is connected to the second input detector 18, while the first input of the GOPP13 is connected to the second output of the phasing device 14, as well as a synchronization device 15, the input of which is connected to the second inputs of the third 10 and fourth 14 multipliers, respectively, while the output of the synchronization device 15 is connected to the second inputs of FOPP12 and GOPP13 respectively.

The prototype device works as follows.

Two frequencies are formed in the GNTC1 transmitter: the clock frequency for FOPP2 and GPP3 and the carrier frequency of the signal. Clock frequencies from the output of GNTC1 are fed to the input of GPP2 and GPP3, which generate binary pseudorandom sequences. These sequences are collections of bipolar DC pulses of the same magnitude and duration, which are determined by the magnitude of the clock frequency. The law of formation of a pseudo-random sequence is chosen so as to provide a small cross-correlation between the pseudo-random sequences of FOPP2 and GLP3 for any phase shift between them (quasi-orthogonal binary pseudorandom sequences). This condition is necessary for the effective separation and suppression of the echo signal in the receiver.

The phasing device 4 sets the shift registers FOPP2 and GLP3 to the same initial state, which provides phase communication of their pseudo-random sequences. Phasing device 4 consists of initial phase decoders FOPP2 and GPP3 and a pulsed phasing scheme, which ensures the combination of their initial states in phase. The binary pseudo-random sequence from the output of FOPP2 is supplied to the multiplier 5. The oscillation of the carrier frequency, which in the multiplier 5 is multiplied by a binary pseudo-random sequence, is supplied to the second input of the multiplier 5 through a 90 ° 7 phase shifter from the output of the GNST1. As a result, a signal is generated at the output of the multiplier 5, which is a carrier frequency oscillation with a constant amplitude, phase-shifted 180 ° according to the law of a binary pseudorandom sequence. The binary pseudorandom sequence from the output of GPP3 is supplied to the multiplier 6, the carrier frequency oscillation is supplied to the second input through the phase manipulator 8 from the output of GNTC1. At the output of the multiplier 6, a signal is formed, which is a oscillation of the carrier frequency with a constant amplitude, phase-manipulated by 180 ° according to the law of a binary pseudorandom sequence.

Depending on the sign of the transmitted information, the phase manipulator 8 rotates the phase of the carrier frequency of the signal at the output of the multiplier 6 relative to the carrier frequency of the signal at the output of the multiplier 5 by 0 or 180 °. Thus, depending on the sign of the transmitted information, the carrier frequencies of these signals are shifted in phase with each other. From the outputs of the multipliers 5 and 6, the signals are fed to the addition circuit 9, which forms the output signal of the transmitter, which is a carrier frequency oscillation with a constant amplitude, phase-shifted by 0 °, 90 °, 180 °, and 270 °, with the moments of manipulation and sequence of these phase values is determined by the ratio of the signs of the elements of binary pseudorandom sequences FOPP2 and GPP3 with the transmitted phase difference.

From addition circuit 9, the signal enters the high-frequency transmitter and is broadcast.

The received signal from the output of the high-frequency receiver is fed to the third 10 and fourth 11 multipliers, similar to the multipliers 5 and 6 of the transmitter. In the multiplier 10, the received signal is multiplied by a binary pseudo-random sequence generated by FOPP12, similar to FOPP2 of the transmitter. The signal from the output of the multiplier 10 is fed to a band-pass filter 16, which distinguishes the oscillation of the carrier frequency of the signal. In the multiplier 11, the received signal is multiplied by a binary pseudo-random sequence, which generates GOPP13, similar to GPP3 of the transmitter. The signal from the output of the multiplier 11 is fed to a band-pass filter 17, which emits a phase-manipulated oscillation of the carrier frequency of the signal.

The phasing device 14, similar to the phasing device 4 of the transmitter, provides phase coupling of the output sequences FOPP12 and GOPP13 corresponding to phase coupling of the sequences FOPP2 and GLP3 of the transmitter.

The binary pseudo-random sequences generated by the generators in the receiver are synchronized with the binary pseudo-random sequences of the received signal using the synchronization device 15. As the synchronization device 15, known synchronization devices can be used to synchronize the local signals of the receiver with one of the main beams of the received multipath signal based on analysis cross-correlation functions of received and local signals.

As is known, when using broadband signals, effective suppression of interfering rays or the addition of several selected strongest rays, as well as suppression of concentrated noise, can be ensured.

Oscillations of the carrier frequency from the outputs of the bandpass filters 16 and 17 are fed to a phase detector 18, which measures the information phase difference between them, and then to the output of the device.

The main disadvantage of the prototype device is not high enough secrecy of the transmitted information.

To eliminate this drawback, a device containing on the transmitting side: a series-coupled DFBP, a first multiplier, an addition circuit, the output of which is the output of the transmitter, a series-connected GLP, a second multiplier, the output of which is connected to the second input of the addition circuit, and a GNSS, the first output which is connected to the first inputs of the FOPP and GPP, respectively, the second output of the GNSS is connected to the first inputs of the phase shifter by 90 ° and the phase modulator, respectively, the output of which is connected to the second input the second multiplier, and the phase shifter output 90 ° is connected to the second input of the first multiplier, and the second inputs of the FOPP and GLP are connected to the corresponding outputs of the phasing device, on the receiving side: phasing device, FOPP, the third multiplier, the first bandpass filter, phase detector, connected in series GOPP, a fourth multiplier, a second bandpass filter, the output of which is connected to the second input of the phase detector, while the first input of the GOPP is connected to the second output of the phase device synchronization device, the input of which is connected to the second inputs of the third and fourth multipliers, respectively, and the output of the synchronization device is connected to the second inputs of the FOPP and GOPP, respectively, according to the invention, are introduced on the transmitting side: the first transmitter decoder, the transmitter counter, the second decoder, connected in series transmitter, first transmitter key, OR transmitter circuit, second transmitter key connected in series, transmitter phase inverter, the output of which is connected is connected to the second input of the OR circuit of the transmitter, and the second output of the second decoder is connected to the first input of the second transmitter key, the second inputs of the first and second transmitter keys are interconnected and are informational, and the second output of the GLP is connected to the input of the first transmitter decoder, and the output of the transmitter counter is connected to the input of the second transmitter decoder using buses, and the output of the OR circuit of the transmitter is connected to the second input of the phase manipulator, while the first output of the GNTC is connected to the second input of the account transmitter, on the receiving side: the first receiver decoder, the receiver counter, the second receiver decoder, the second receiver key, the phase inverter, the receiver OR circuit, the output of which is information, the second valve in series, the first receiver key whose output is connected to the second input of the OR circuit of the receiver, while the second output of the second decoder of the receiver is connected to the second input of the first key of the receiver, and the second input of the second key of the receiver is connected to the output of the first a gate, the input of which is connected to the output of the phase detector, the second output of the GOPP connected to the input of the first decoder, and the output of the receiver counter connected to the input of the second decoder of the receiver via buses, and the output of the synchronization device connected to the second input of the receiver counter.

Figure 2 shows the functional diagram of the proposed device, where indicated:

1 - generator oscillations of the carrier clock frequency (GNST);

2 - shaper orthogonal pseudo-random sequence (FOPP);

3 - pseudo-random sequence generator (GLP);

4 - phasing device;

5, 6 - the first and second multipliers;

7 - phase shifter 90 °;

8 - phase manipulator;

9 is a diagram of addition;

10, 11 - the third and fourth multipliers;

12 - shaper orthogonal pseudo-random sequence (FOPP),

13 - generator reference pseudo-random sequence (GOPP);

14 - phasing device;

15 - synchronization device;

16, 17 - the first and second band-pass filters;

18 - phase detector;

19 - the first transmitter decoder;

20 is an OR transmitter diagram;

21 - transmitter phase inverter;

22, 23 - the first and second keys of the transmitter;

24 - transmitter counter;

25 - second transmitter decoder;

26 - the first receiver decoder;

27 - receiver counter;

28 - second receiver decoder;

29 - the second key of the receiver;

30 - the first key of the receiver;

31 - phase inverter;

32 is a receiver OR diagram;

33, 34 - the first and second valves.

The proposed device contains on the transmitting side: sequentially connected FOPP2, a first multiplier 5, addition circuit 9, the output of which is the output of the transmitter, series-connected GLP3, a second multiplier 6, the output of which is connected to the second input of the addition circuit 9, sequentially connected to the first decoder of the transmitter 19, transmitter counter 24, second transmitter decoder 25, first transmitter key 22, OR circuit of transmitter 20, the output of which is connected to the second input of the phase manipulator 8, is connected in series the second key of the transmitter 23, the phase inverter of the transmitter 21, the output of which is connected to the second input of the OR circuit of the transmitter 20, as well as the GNTC1, the first output of which is connected to the first inputs of the FOPP2, GPP3, with the second input of the transmitter counter 24, the second output of the GNTC1 is connected to the first inputs of the phase manipulator 8 and phase shifter 90 ° 7, the output of which is connected to the second input of the first multiplier 5, while the second output of the GPP3 is connected to the input of the first decoder of the transmitter 19 and the output of the transmitter counter 24 is connected to the input of the second decoder the transmitter 25 using buses, and the second output of the second transmitter decoder 25 is connected to the first input of the second transmitter key 23, the second inputs of the first 22 and second 23 transmitter keys are interconnected and are informational, and the second inputs of FOPP2 and GPP3 are connected to the corresponding outputs phasing device 4, also the output of the phase manipulator 8 is connected to the second input of the second multiplier 6.

On the receiving side: a phasing device 14, FOPP12, a third multiplier 10, a first bandpass filter 16, a phase detector 18, a second gate 34, a first receiver key 30, the output of which is connected to the second input of the OR circuit of the receiver 32, connected in series to GOPP13, in series , the fourth multiplier 11, the second bandpass filter 17, the output of which is connected to the second input of the phase detector 18, the first decoder of the receiver 26, the counter of the receiver 27, the second decoder of the receiver 28, the second key of the receiver 29, in series zoinverter 31, the OR circuit of the receiver 32, the output of which is the information output of the receiver, as well as a synchronization device 15, the input of which is connected to the second inputs of the third 10 and fourth 11 multipliers, the output of the synchronization device 15 is connected to the second inputs of FOPP12, GOPP13, the receiver counter 27, while the second output of the GOPP13 is connected to the input of the first decoder of the receiver 26 and the output of the counter of the receiver 27 is connected to the input of the second decoder of the receiver 28 using buses, and the second output of the phasing device 14 is connected to GOPP13 th input and the second output of the second decoder receiver 28 is connected to a second input of the first receiver switch 30 and the output of the phase detector 18 is connected to the inlet of the first valve 33.

The proposed device operates as follows.

Two frequencies are formed in the GNTC1 transmitter: the clock frequency for FOPP2 and GPP3 and the carrier frequency of the signal. The clock frequency from the output of GNTC1 is fed to the input of FOPP2 and GPP3, which generate binary pseudorandom sequences. These sequences are collections of bipolar DC pulses of the same magnitude and duration, which are determined by the magnitude of the clock frequency. The law of formation of pseudo-random sequences is chosen so as to provide a small cross-correlation between the pseudo-random sequences of FOPP2 and GLP3 for any phase shift between them (quasi-orthogonal binary pseudo-random sequences). This condition is necessary for their effective separation and suppression of the echo signal in the receiver.

The phasing device 4 sets the shift registers FOPP2 and GLP3 to the same initial state, which provides phase communication of their pseudo-random sequences. Phasing device 4 consists of initial phase decoders FOPP2 and GPP3 and a pulsed phasing scheme, which ensures the combination of their initial states in phase. The binary pseudo-random sequence from the output of FOPP2 is supplied to the multiplier 5. The oscillation of the carrier frequency, which in the multiplier 5 is multiplied by a binary pseudo-random sequence, is supplied to the second input of the multiplier 5 through a 90 ° 7 phase shifter from the output of the GNST1. As a result, a signal is generated at the output of the multiplier 5, which is a carrier frequency oscillation with a constant amplitude, phase-shifted 180 ° according to the law of a binary pseudorandom sequence. The binary pseudo-random sequence from the output of GPP3 is supplied to the multiplier 6, to the second output of which, through the phase manipulator 8, the carrier frequency oscillates from the output of the GNTC1. At the output of the multiplier 6, a signal is formed, which is a oscillation of the carrier frequency with a constant amplitude, phase-manipulated by 180 ° according to the law of a binary pseudorandom sequence.

The transmitted information is fed to the signal inputs of the first 22 and second 23 keys of the transmitter, which are controlled by the signals coming from the outputs of the second decoder 25, which are formed as follows. The first decoder 19 decrypts the signal, for example, all units coming from GPP3 with the issuance of one pulse at its output. When this state appears in the register bits of the pseudorandom sequence generator (GLP), this signal sets the counter of transmitter 24 to zero. From the output of the counter of the transmitter 24, the signal enters the second decoder of the transmitter 25, which converts the binary state of the counter into key management signals. If the first key of the transmitter 22 is open, then the signal through it goes to the OR circuit of the transmitter 20, and then to the phase manipulator 8. If the second key of the transmitter 23 is open, the signal goes to the phase inverter of the transmitter 21, where it rotates the signal phase by 180 ° and then, through the transmitter circuit 20, it enters the phase manipulator 8. Depending on the sign of the transmitted information, the phase manipulator 8 rotates the phase of the carrier frequency of the signal at the output of the first transmitter multiplier 5.

Thus, depending on the sign of the transmitted information, the carrier frequency of these signals is shifted in phase with each other. From the outputs of the first 5 and second 6 multipliers, the signals are fed to the addition circuit 9, which forms the output signal of the transmitter, which is a carrier frequency oscillation with a constant amplitude, phase-shifted by 0 °, 90 °, 180 °, and 276 °, and the moments of manipulation and the sequence of these phase quantities is determined by the ratio of the signs of the elements of the binary pseudo-random sequences FOPP2 and GLP3 and the transmitted phase difference.

From addition circuit 9, the signal is fed to a high-frequency transmitter and radiated into the air.

The received signal from the output of the high-frequency receiver is fed to the inputs of the third 10 and fourth 11 multipliers. In the third 10 multiplier, the received signal is multiplied by a binary pseudo-random sequence that FOPP12 generates.

The signal from the output of the third multiplier 10 is fed to the first band-pass filter 16, which emits oscillations in the carrier frequency of the signal. In the fourth multiplier 11, the received signal is multiplied by a binary pseudo-random sequence that GOPP13 generates. The signal from the output of the fourth multiplier 11 is fed to a second band-pass filter 17, which emits a phase-controlled oscillation of the carrier frequency of the signal. The phasing device 14 provides phase coupling of the output sequences FOPP12 and GOPP13 corresponding to phase coupling of the sequences FOPP2 and GOPP13 of the transmitter. The binary pseudo-random sequences generated by the generator in the receiver are synchronized with the binary pseudo-random sequences of the received signal using the synchronization device 15. As the synchronization device 15, known synchronization devices can be used to synchronize the local signals of the receiver with one of the main beams of the received multipath signal based on analysis cross-correlation functions of the received and local signals.

Oscillations of the carrier frequency from the outputs of the first 16 and second 17 bandpass filters are fed to a phase detector 18, which measures the information phase difference between them and then to the inputs of the first 33 and second 34 gates.

The signal from the output of GOPP13, in addition, is fed by a bus to the input of the first decoder of the receiver 26, which decodes the signal, for example, all units, with the output of one pulse at its output. When this state appears in the register bits of the reference pseudorandom sequence generator (GOPP), this signal sets the counter of the receiver 27 to the zero state. From the output of the counter of the receiver 27, the signal is supplied to the second decoder of the receiver 28, which converts the binary state of the counter into control signals of the first 30 and second 29 keys of the receiver. The first key of the receiver 30 opens when the positive signal at the output of the phase detector 18 arrives through the second gate 34 and passes the positive signal. The second key of the receiver 29 opens when the output of the phase detector 18 is a negative signal that passes through the first gate 33, passing a negative signal. The signal at the output of the second key of the receiver 29 is fed to the input of the phase inverter 31, which rotates the phase of this signal by 180 °. Information signals from the output of the first key of the receiver 30 and from the output of the phase inverter 31 are fed to the circuit "OR" of the receiver 32 and to the output of the device.

Claims (1)

A radio communication line with increased secrecy of the transmitted information, containing on the transmitting side a series-connected shaper of an orthogonal pseudo-random sequence, a first multiplier, an addition circuit, the output of which is the output of the transmitter, a series-connected pseudo-random sequence generator, a second multiplier, the output of which is connected to the second input of the addition scheme, and also a carrier oscillation generator, the first output of which is connected to the first inputs of the the orthogonal pseudo-random sequence generator and the pseudo-random sequence generator, and the second output of the carrier clock oscillator is connected to the first inputs of the phase shifter by 90 ° and the phase manipulator, the output of which is connected to the second input of the second multiplier, the output of the phase shifter by 90 ° is connected to the second input of the first multiplier, moreover, the second inputs of the orthogonal pseudo-random sequence generator and the pseudo-random sequence generator are connected to the corresponding the outputs of the phasing device, on the receiving side, a phasing device, an orthogonal pseudo-random sequence generator, a third multiplier, a first bandpass filter, a phase detector, a series-connected reference pseudorandom sequence generator, a fourth multiplier, a second bandpass filter, the output of which is connected to the second input of the phase detector, wherein the first input of the reference pseudo-random sequence generator is connected to the second input of the devices and phasing, as well as a synchronization device that synchronizes the local signals of the receiver with the received signal, the input of which is connected to the second inputs of the third and fourth multipliers, and the output of the synchronization device is connected to the second inputs of the orthogonal pseudorandom sequence generator and the reference pseudorandom sequence generator, respectively, characterized in that the first transmitter decoder, transmitter counter, n subsequently connected to the second transmitter decoder, the first transmitter key, the OR circuit of the transmitter, the second transmitter key connected in series, the phase inverter of the transmitter, the output of which is connected to the second input of the OR transmitter, while the second output of the second transmitter decoder is connected to the first input of the second transmitter key, and the second inputs the first and second transmitter keys are interconnected and are informational, and the second output of the pseudo-random sequence generator with the input of the first the transmitter decoder and the output of the transmitter counter with the input of the second transmitter decoder are connected via buses, and the second input of the transmitter counter is connected to the first output of the carrier clock oscillator and the output of the OR circuit of the transmitter is connected to the second input of the phase manipulator, on the receiving side: the first decoder connected in series receiver, receiver counter, serially connected second receiver decoder, second receiver key, phase inverter, OR circuit of the receiver, the output of which is with the information output of the device, the second gate is connected in series, the first receiver key, the output of which is connected to the second input of the OR circuit of the receiver, and the second input of the first receiver key is connected to the second output of the second receiver decoder, and the second output of the reference pseudo-random sequence generator with the input of the first the receiver decoder and the output of the receiver counter with the input of the second receiver decoder are connected via buses, and the second input of the receiver counter is connected to the output of the sync device ronization, in addition, the first and second gates, the inputs of which are connected to each other and to the output of the phase detector, and the output of the first valve is connected to the second input of the second key of the receiver.

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