RU2504903C2 - Regional information communication system - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: regional information communication system comprises a monitoring and control station and territorially distributed objects connected to each other by two-way radio communication, wherein the frequencies of heterodynes, narrowband filters and frequency selectors are related in a certain manner.

EFFECT: high selectivity, noise immunity and reliability of two-way radio communication between a monitoring and control station and each territorially distributed object by suppressing spurious signals received through additional channels.

3 cl, 3 dwg

Description

The proposed system relates to duplex radio communication and can be used to transmit control and signaling signals from a control point to a large group of geographically distributed objects, as well as to collect information from these objects for centralized control of technological processes of geographically distributed objects (stationary and mobile) .

Communication information systems are known (ed. Certificate of the USSR No. 830.304, 930.254, 1.075.426, 1.233.105, 1.276.594, 1.522.417, 1.626.439, 1.665.531, 1.780.080; RF patents No. 2.049. 372, 2.094.853, 2.107.991, 2.113.012, 2.115.251, 2.122.239, 2.128.886, 2.172.524, 2.264.034; US patent No. 5.574.648;

French patent No. 2,438.877; EP patent No. 0.669.740 and others).

Of the known systems, the closest is the "Regional Information Communication System" (RF patent No. 2.264.034, Н04 В 7/00, 2004), which is selected as a prototype.

The specified system provides duplex radio communication between the monitoring and control center and each geographically distributed object using complex signals with combined amplitude modulation and phase shift keying (AM-FMN) and two frequencies ω ₁ and ω ₂ .

The composition of the known system includes superheterodyne receivers in which the same value of the second intermediate frequency ω _pr2 can be obtained by receiving signals at the following frequencies:

_np2 ω = ω ₁ -ω _{r1, np2} ω = ω _z2 -ω _2,

_WP2 w = ω _{d1 P1} -ω, ω _WP2 = ω _P2 -ω _r2.

Therefore, if the tuning frequencies ω ₁ and ω ₂ are the main receiving channels, then along with them there are mirror receiving channels, the frequencies ω _z1 and ω _z2 are located symmetrically to the frequencies ω _g1 and ω _g2 local oscillators (figure 3). The conversion on the mirror channels of reception occurs with the same conversion coefficient Kpr as on the main channels. Therefore, mirror reception channels most significantly affect the selectivity and noise immunity of superheterodyne receivers.

In addition to mirrored, there are other additional (Raman and direct channel) receive channels.

In general terms, any combination receive channel takes place when the following conditions are met:

,

,

,

,

where ω _ki is the frequency of the i-th Raman channel;

m, n, i are positive integers.

The most harmful Raman reception channels are those generated by the interaction of the first harmonic of the signal frequency with the harmonics of the frequencies of small local oscillators (second, third), since the sensitivity of the receivers on these channels is close to the sensitivity of the main channels.

So four combinational channels with m = 1 and n = 2 correspond to frequencies

ω _k1 = 2ω _{g1 -ω pr2} , ω _k2 = 2ω _g1 + ω _pr2 ,

ω _k3 = 2ω _{np2 z2} -ω, ω _k4 = 2ω + ω _{z2 np2,}

If the frequency ω _{p of the} false signal (interference) is equal to the second intermediate frequency ω _pr2 (ω _p = ω _pr2 ); a direct passage channel is formed, for which the elements and blocks of the receivers are simple transmission links.

The presence of false signals (interference) received via mirror and Raman channels, as well as through direct channels, leads to a decrease in the selectivity, noise immunity and reliability of duplex radio communication between a monitoring and control point and each geographically distributed object.

An object of the invention is to increase the selectivity, noise immunity and reliability of duplex radio communication between a monitoring and control point and each geographically distributed object by suppressing false signals (interference) received via additional channels.

The problem is solved in that the regional communication information system containing radio stations installed at the monitoring and control point and each geographically distributed object, wherein each radio station is made in the form of a series-connected source of analog messages, an amplitude modulator, the second input of which is connected to the output of the generator carrier frequency, phase manipulator, the second input of which is connected to the output of the source of discrete messages, the first mixer, the second input of which dinene with the output of the first local oscillator, the first intermediate frequency amplifier, the first power amplifier, the duplexer, the input-output of which is connected to the transceiver antenna, the second power amplifier, the second mixer, the second input of which is connected to the output of the second local oscillator, and the second intermediate frequency amplifier, connected in series an amplitude limiter, a synchronous detector and a recording and analysis unit, connected in series to the output of the amplitude limiter of the multiplier, the second input of which is connected n with the output of the first local oscillator, a bandpass filter and a phase detector, the second input of which is connected to the output of the second local oscillator, and the output is connected to the second input of the recording and analysis unit, differs from the nearest analogue in that each radio station is equipped with two narrow-band filters, a phase inverter, an adder, a frequency selector, an amplitude detector, a threshold block and a key, and the first narrow-band filter, phase inverter, adder, the second input of which are connected to the output of the second power amplifier connected to the output of the second power amplifier, a frequency selector, the second input of which is connected to the output of the first local oscillator, a second narrow-band filter, an amplitude detector, a threshold block and a key, the second input of which is connected to the output of the amplifier of the second intermediate frequency, and the output is connected to the input of the amplitude limiter and the second input of the synchronous detector.

The regional communication information system contains a control and management point and geographically distributed objects interconnected by duplex radio communication. To do this, radio control stations are installed at the control and management point and in geographically distributed objects, using complex signals with combined amplitude modulation and phase shift keying (AM-FMN) and two frequencies ω ₁ and ω ₂ .

Each radio station contains a series-connected source 1.1 (1.2) of analog messages, an amplitude modulator 4.1 (4.2), the second input of which is connected to the carrier frequency generator 3.1 (3.2), a phase manipulator 5.1 (5.2), the second input of which is connected to the output of the source 6.1 (6.1) ) discrete messages, the first mixer 9.1 (9.2), the second input of which is connected to the output of the first local oscillator 8.1 (8.2), the amplifier 10.1 (10.2) of the first intermediate frequency, the first power amplifier 11.1 (11.2), duplexer 12.1 (12.2), input-output which is connected to the transceiver antenna 13.1 (13 .2), the second power amplifier 15.1 (15.2), the second mixer 17.1 (17.2), the second input of which is connected to the output of the second local oscillator 16.1 (16.2), and the amplifier 18.1 (18.2) of the second intermediate frequency. The output of the second power amplifier 15.1 (15.2) is connected in series to the first narrow-band filter 25.1 (25.2), the phase inverter 26.1 (26.2), the adder 27.1 (27.2), the second input of which is connected to the output of the second power amplifier 15.1 (15.2), the selector 28.1 (28.2) frequency, the second input of which is connected to the output of the first local oscillator 8.1 (8.2), the second narrow-band filter 29.1 (29.2), the amplitude detector 30.1 (30.2), the threshold block 31.1 (31.2), the key 32.1 (32.2), the second input of which is connected to the output of the first local oscillator 8.1 (8.2), amplitude limiter 19.1 (19.2), synchronous detector 20.1 (20.2), second input coupled to an output key 32.1 (32.2), and the block 24.1 (24.2) reception and analysis. To the output of the amplitude limiter 19.1 (19.2), a multiplier 21.1 (21.2) is connected in series, the second input of which is connected to the output of the first local oscillator 8.1 (8.2), a bandpass filter 22.1 (22.2), and a phase detector 23.1 (23.2), the second input of which is connected to the output of the second the local oscillator 16.1 (16.2), and the output is connected to the second output of the block 24.1 (24.2) registration and analysis.

The oscillator 3.1 (3.2) of the carrier frequency, the amplitude modulator 4.1 (4.2) and the phase manipulator 5.1 (5.2) form a modulator 2.1 (2.2) with a double type of modulation.

The first local oscillator 8.1 (8.2), the first mixer 9.1 (9.2), the amplifier 10.1 (10.2) of the first intermediate frequency and the first power amplifier 11.1 (11.2) form the transmitter 7.1 (7.2). The second amplifier 15.1 (15.2), the second local oscillator 16.1 (16.2), the second mixer 17.1 (17.2), the amplifier 18.1 (18.2) of the second intermediate frequency, the amplitude limiter 19.1 (19.2), the synchronous detector 20.1 (20.2), the multiplier 21.1 (21.2), band-pass filter 22.1 (22.2), phase detector 23.1 (23.2), first narrow-band filter 25.1 (25.2), phase inverter 26.1 (26.2), adder 27.1 (27.2), frequency selector 28.1 (28.2), second narrow-band filter 29.1 (29.2), amplitude detector 30.1 (30.2), threshold block 31.1 (31.2) and key 32.1 (32.2) form a receiver 14.1 (14.2).

The tuning frequency ω _{n3 of the} first narrow-band filter 25.1 (25.2) is chosen equal to the second intermediate frequency ω _n3 = ω _pr2 .

The tuning frequency ω _{n1 of the} frequency selector 28.1 and the second narrow-band filter 29.1 of the radio station installed at the monitoring and control station is chosen to be equal to the frequency ω _{g1 of the} first local oscillator 8.1 and the frequency ω _{2 of the} received signal ω _n1 = ω _g1 = ω ₂ , which corresponds to the resonance phenomenon.

Tuning frequency ω _2n frequency selector 28.2 and second 29.2 narrowband filter station installed on each geographically-distributed object selected equal to the frequency ω _z2 first LO frequency and the received signal ω ₁ = ω ω _{2n r2} = ω _1, which corresponds to a resonance phenomenon.

Between the monitoring and control point and each geographically distributed object, duplex radio communication is established using complex signals with combined amplitude modulation and phase shift keying (AM-FMN) on one carrier frequency.

At the same time, at the monitoring and control station, these signals are emitted at a frequency

ω = ω ₁ = ω _{pr1 r2.}

where ω _CR1 is the first intermediate frequency;

ω _g2 - the frequency of the local oscillator 16.1 (8.2),

but taken at a frequency

ω ₂ = ω _pr3 = ω _g1 ,

where ω _CR1 is the third intermediate frequency;

ω _g2 is the local oscillator frequency 8.1 (16.2).

At a geographically distributed facility, on the contrary, complex AM-PSK signals are emitted at a frequency of ω ₂ and received at a frequency of ω ₁ .

The frequencies ω _g1 and ω _{g2 of the} local oscillators 8.1 (16.2) and 16.1 (8.2) are spaced by the value of the second intermediate frequency (figure 3)

-ω ω _{r2 r1} = 2ω _WP2

Regional communication information system operates as follows.

When transmitting messages and commands from the control and management point, the carrier frequency generator 3.1 is turned on, which generates a high-frequency oscillation

u _c1 (t) = υ _c1 cos (ω _c t + φ _c1 ), 0≤t≤T _c1

where υ _c1 , ω _с , φ _c1 , T _c1 - amplitude, carrier frequency, initial phase and duration of high-frequency oscillations,

which is supplied to the first input of the amplitude modulator 4.1, the second input of which from the output of the source 1.1 of analog messages is supplied with a modulating function m ₁ (t) containing analog information. At the output of the amplitude modulator 4.1, an amplitude-modulated (AM) signal is generated

u ₁ (t) = υ _c1 [1 + m ₁ (t)] · cos (ω _c t + φ _c1 ), 0≤t≤T _c1 ,

which is fed to the first input of the phase manipulator 5.1, to the second input of which a modulating code M ₁ (t) is supplied from the output of the source 6.1 discrete messages. At the output of the 5.1 phase manipulator, a complex signal is formed with combined amplitude modulation and phase manipulation (AM-FMn)

u ₂ (t) = υ _c1 [1 + m ₁ (t)] · cos (ω _c t + φ _k1 (t) + φ _c1 ), 0≤t≤T _c1 ,

where φ _k1 (t) = {0, π} is the manipulated phase component that displays the phase manipulation law in accordance with the modulating code M ₁ (t), and φ _k1 (t) = const for kτ _e <t <(k + 1 ) τ _e and can be measured abruptly at, i.e., at the boundaries between elementary premises (k = 0, 1, 2, ..., N ₁ -1);

τ _e , N ₁ - the duration and number of chips that make up a signal of duration T _c1 (T _c1 = N ₁ · τ _e ),

which is fed to the first input of the first mixer 9.1, the second of which is supplied with the voltage of the first local oscillator 8.1.

u _g1 (t) = υ _g1 · cos (ω _g1 t + φ _g1 ),

At the output of the mixer 9.1, voltages of combination frequencies are generated. Amplifier 10.1 distinguishes the voltage of the first intermediate (total) frequency

u _pr1 (t) = υ _pr1 [1 + m ₁ (t)] · cos [(ω _pr1 t + φ _k1 (t) + φ _pr1 ] 0≤t≤T _c1

When υ _pr1 = 1 / 2υ _s1 · υ _g1 ;

ω _pr1 = ω _s + ω _g1 = ω ₁ - the first intermediate (total) frequency;

φ _pr1 = φ _c1 + φ _g1 .

This voltage after amplification in the power amplifier 11.1 through the duplexer 12.1 enters the transceiver antenna 13.1, is radiated by it at a frequency ω _{1, is} captured by the transceiver antenna 13.2 of a geographically distributed object, and is fed through the duplexer 12.2 and the power amplifier 15.2 to the first input of the mixer 17.2, at the second input of which a voltage u _g1 (t) of the local oscillator 16.2 is supplied. At the output of the mixer 17.2, voltages of combination frequencies are generated. Amplifier 18.2 distinguishes the voltage of the second intermediate (differential) frequency

u _pr2 (t) = υ _pr2 [1 + m ₁ (t)] · cos [ω _pr2 t + φk ₁ (t) + φ _pr2 ], 0≤t≤T _c1

when υ _pr2 = 1 / 2υ _pr1 · υ _g1 ;

ω _p2 = ω _{pr1 -ω g1} - the second intermediate (difference) frequency;

φ _pp2 = φ _pr1 -φ _g1 .

At the same time, the voltage u _pr1 (t) from the output of the power amplifier 15.2 through the adder 27.2, which has only one arm, is supplied to the first input of the frequency selector 28.2, the second input of which supplies the local oscillator voltage 8.2.

u _g2 (t) = υ _g2 cos (ω _g2 t + φ _g2 ),

As the frequency selector 28.2 may be used vibrational system, wherein selected frequency ω equal to the frequency setting _2n ω _z2 LO 8.2 (ω _2n = ω _z2). When the voltage frequency u _pr1 (t) arrives at the first input of the selector 28.2, a resonance phenomenon occurs in the oscillatory system (circuit).

The output voltage of the frequency selector 28.2 is allocated by a narrow-band filter 29.2, detected by the amplitude detector 30.2 (υ) and fed to the input of the threshold unit 31.2, where it is compared with the threshold voltage υ _then .

At resonance, the output voltage of the frequency selector 28.2 reaches its maximum value, the voltage υ _{max of the} amplitude detector 30.2 exceeds the threshold level υ _then in the threshold block 31.2 (υ _max > υ _then ). And only above a threshold level in the threshold _then υ 31.2 block formed constant voltage is supplied to the control input of switch 32.2 and opens it. In the initial state, the key 32.2 is always closed. In this case, the voltage u _pr2 (t) from the output of the amplifier 18.2 of the second intermediate frequency through the public key 32.2 is fed to the input of the amplitude limiter 19.2 and to the first (information) input of the synchronous detector 20.2. At the output of the amplitude limiter 19.2, a voltage is generated

u ₃ (t) = υ ₀ · cos [ω _CR2 t + φ _k1 (t) + φ _CR2 ], 0≤t≤T _s1

where υ ₀ is the limit threshold,

which is used as the reference voltage and is fed to the second (reference) input of the synchronous detector 20.2. The output of the latter forms a low-frequency voltage

u _н1 (t) = υ _н1 [1 + m ₁ (t)], 0≤t≤T _c1 ,

where υ _н1 = 1 / 2υ _пр2 · υ ₀ ,

proportional to the modulating function m ₁ (t).

This voltage is supplied to the first input of the executive unit 24.2. The voltage u ₃ (t) from the output of the amplitude limiter 19.2 simultaneously arrives at the first input of the multiplier 21.2, the second input of which is the voltage of the local oscillator 8.2

u _g2 (t) = υ _g2 cos (ω _g2 t + φ _g2 ),

At the output of the multiplier 21.2 voltage is formed

u ₄ (t) = υ ₄ · cos [ω _g1 t + φ _k1 (t) + φ _g1 ], 0≤t≤T _c1

₄ where υ = 1 / 2υ ₀ · υ _r2

which is an FMN signal at a frequency of ω _g2 local oscillator 16.2. This voltage is allocated by a band-pass filter 22.2 and supplied to the first (information) input of the phase detector 23.2, the second (reference) input of which is supplied with the voltage u _g1 (t) of the local oscillator 16.2. The output of the phase detector 23.2 produces a low-frequency voltage

u _n2 (t) = υ _n2 · cosφ _k1 (t), 0≤t≤T _c1 ,

where u _n2 = 1 / 2υ ₄ · υ _g1 ,

proportional to the modulating code M ₁ (t). This voltage is supplied to the second input of the executive unit 24.2.

When transmitting messages from a geographically distributed object using a carrier frequency generator 3.2, a high-frequency oscillation is generated

u _c2 (t) = υ _c2 · cos (ω _c t + φ _c2 ), 0≤t≤T _c2 ,

which is fed to the first input of the amplitude modulator 4.2, to the second input of which from the output of the source 1.2 of analog messages is fed a modulating function m ₂ (t) containing analog information. The output of the amplitude modulator 4.2 produces a signal with amplitude modulation (AM)

u ₅ (t) = υ _c2 [1 + m ₂ (t)] · cos [ω _c t + φ _c2 ], 0≤t≤T _c2 ,

which is fed to the first input of the phase manipulator 5.2, to the second input of which a modulating code M ₂ (t) is supplied from the output of the source 6.2 of discrete messages. At the output of the phase manipulator 5.2, a complex signal is formed with combined amplitude modulation and phase manipulation (AM-FMn)

u ₆ (t) = υ _c2 [1 + m ₂ (t)] · cos [(ω _c t + φ _k2 (t) + φ _c2 ], 0≤t≤T _c2 ,

which goes to the first input of the mixer 9.2, to the second input of which the voltage of the first local oscillator 8.2

u _g2 (t) = υ _g2 cos (ω _g2 t + φ _g2 ),

At the output of the mixer 9.2, a voltage of combination frequencies is generated. Amplifier 10.2 distinguishes the voltage of the third intermediate frequency

u ₇ (t) = υ ₇ [1 + m ₂ (t)] · cos [ω _CR3 t-φ _k2 (t) + φ _CR3 ], 0≤t≤T _c2 ,

₇ where υ = 1 / 2υ _c2 · υ _r2;

_PR3 ω = ω _z2 -ω _c = ω ₂ - third intermediate (difference) frequency;

_PR3 cp = φ -φ _{r2 s2.}

This voltage, after amplification in the power amplifier 11.2 through the duplexer 12.2, enters the transceiver antenna 13.2, is radiated by it at the frequency ω ₂ , is captured by the transceiver antenna 13.1 of the monitoring and control point, and through the duplexer 12.1 and the power amplifier 15.1 is supplied to the first input of the mixer 17.1, the second input of which a voltage u _g2 (t) of the local oscillator 16.1 is supplied. At the output of the mixer 17.1, voltages of combination frequencies are generated. Amplifier 18.1 distinguishes the voltage of the second intermediate frequency

u _pr3 (t) = υ _pr3 [1 + m ₂ (t)] · cos [ω _pr2 t-φ _k2 (t) + φ _pr2 ], 0≤1≤T _s2 ,

_PR3 where υ = 1 / 2υ ₇ -υ _r2;

_np2 ω = ω _z2 -ω ₂ - second intermediate (difference) frequency;

φ _pr2 = φ _r2 -φ _pr3 .

At the same time, the voltage u ₇ (t) from the output of the power amplifier 15.1 through the adder 27.1, which only has one arm, is supplied to the first input of the frequency selector 28.1, the second input of which supplies the local oscillator voltage 8.1

u _g1 (t) = υ _g2 · cos (ω _g1 t + φ _g1 ).

As a frequency selector 28.1, an oscillatory system can be used, the tuning frequency ω _n , which is chosen equal to the frequency ω _{n of the} local oscillator 8.1 (ω _n = ω _g1 ). The output voltage of the frequency selector 28.1 is extracted by a narrow-band filter 29.1, detected by the amplitude detector 30.1 (υ) and fed to the input of the threshold unit 31.1, where it is compared with the threshold voltage υ _then .

With the resonance that occurs when ω ₂ = ω _g1 , the output voltage of the frequency selector 28.1 reaches its maximum value, the voltage of the amplitude detector 30.1 υ _max exceeds the threshold level υ _pores in the threshold block 31.1 (υ _max > υ _pores ). And only when the threshold level υ _{then is} exceeded (this happens only when the resonance occurs), a constant voltage is generated in the threshold block 31.1, which is supplied to the control input of the key 32.1 and opens it. In the initial state, the key 32.1 is always closed. In this case, the voltage u _pr3 (t) from the output of the amplifier 18.1 of the second intermediate frequency through the public key 32.1 is fed to the input of the amplitude limiter 19.1 and to the first (information) input of the synchronous detector 20.1. At the output of the amplitude limiter 19.1, a voltage is generated

u ₈ (t) = υ ₀ · cos [ω _CR2 t + φ _k2 (t) + φ _CR2 ], 0≤t≤T _c2

which is used as a reference voltage and is supplied to the second (reference) input of the synchronous detector 20.1. A low-frequency voltage is generated at the output of the synchronous detector 20.1

u _n3 (t) = υ _n3 · [1 + m ₂ (t)], 0≤t≤T _c2 ,

where υ _n2 = 1 / 2υ ₄ · υ _g1 ,

proportional to the modulating function m ₁ (t). This voltage is supplied to the first input of the block 24.1 registration and analysis.

The voltage u ₈ (t) from the output of the amplitude limiter 19.1 is simultaneously supplied to the first input of the multiplier 21.1, the second input of which is supplied with the voltage U _g1 (t) of the local oscillator 8.1. At the output of the multiplier 21.1, a voltage is generated

₉ u (t) = υ ₉ · cos [ω _{r2 t + φ k2 (t) +} φ _r2], 0≤t≤T _c2,

where υ ₉ = 1 / 2υ ₀ · υ _g1 ,

which is an FMN signal at a frequency of ω _g2 local oscillator 16.1. This voltage is allocated by a band-pass filter 22.1 and fed to the first (information) input of the phase detector 23.1, the second (reference) input of which is supplied with the voltage u _g2 (t) of the local oscillator 16.1. The output of the phase detector 23.1 produces a low-frequency voltage

u _woofer (t) = υ _woofer cosφ _k2 (t), 0≤t≤T _c2 ,

υ where _nch = 1 / 2υ ₉ · υ _r2

proportional to the modulating code M ₁ (t). This voltage is supplied to the second input 24.1 registration and analysis.

The operation of the receivers 14.1 (14.2) described above corresponds to the case of receiving useful PSK signals through the main channels at frequencies ω ₁ and ω ₂ (Fig. 3).

If a false signal (interference) is received on the first mirror channel at frequencies ω _s1

_Z1 u (t) = υ _P1 · cos [ω t + φ _{P1 P1]} 0≤t≤T _P1,

the output power of the amplifier 15.2 by adder 27.2, which is only one shoulder, he arrives at the first input of the frequency selector 28.2, _H2 tuning frequency ω is chosen equal to the frequency ω LO _r2 8.2 (ω _2n = ω _{z2). R2} frequencies ω _P1 and ω are spaced by twice the value of the second intermediate frequency ω _z2 -ω _P1 = 2ω _np2. Therefore, the resonance phenomenon does not occur in the frequency selector 28.2, the output voltage d of the amplitude detector 30.2 does not exceed the threshold level in the threshold block 31.2 (υ <υ _pore ). The key 32.2 does not open and a false signal (interference) received on the first mirror channel at a frequency ω _s1 is suppressed. For this purpose, the resonance frequency properties 28.2 selector, made in the form of an oscillatory circuit with the tuning frequency ω = ω _{2n r2.}

If a false signal (interference) is received on the second mirror channel at a frequency ω _z2

u _s2 (t) = υ _s2 · cos [ω t + φ _{s2 s2],} 0≤t≤T _P1,

then from the output of the power amplifier 15.1 through the adder 27.1, which has only one arm, it goes to the first input of the frequency selector 28.1, the tuning frequency ω _{n1 of} which is chosen equal to the frequency ω _{g1 of the} local oscillator 8.1 (ω _n1 = ω _g1 ). The frequencies ω _d1 and ω _s2 are spaced by twice the value of the second intermediate frequency ω _s2 = 2ω -ω _{r1 np2.}

Therefore, in the selector 28.1 the frequency of the resonance phenomenon does not occur, the output voltage υ of the amplitude detector 30.1 does not exceed the threshold level υ _then in the threshold block 31.1 (υ <υ _then ). The key 32.1 does not open and a false signal (interference) received on the second mirror channel at a frequency ω _s2 is suppressed. For this, the resonance properties of the frequency selector 28.1 are used, made in the form of an oscillatory circuit with a tuning frequency of ω _s1 = ω _g1 .

For a similar reason, false signals (interference) received through other additional (first ω _k1 , second ω _k2 , third ω _k3 , fourth ω _k4 Raman) channels are also suppressed.

If a false signal (interference) is received through direct channels at a frequency ω _p = ω _CR2

u _p (t) = υ _p · cos [ω _p t + φ _p ], 0≤t≤T _p ,

then from the output of the power amplifier 15.1 (15.2) it goes to the first input of the adder 27.1 (27.2) and to the input of the narrow-band filter 25.1 (25.2), the tuning frequency ω _{n3 of} which is chosen equal to the second intermediate frequency (ω _n3 = ω _pr2 ). The specified false signal (interference) is allocated by a narrow-band filter 25.1 (25.2) and fed to the input of the phase inverter 26.1 (26.2), at the output of which a voltage is generated

u _p1 (t) = - υ _p · cos [ω _p t + φ _p ], 0≤t≤T _p .

This voltage is supplied to the second input of the adder 27.1 (27.2).

The voltage u _p (t) and u _p1 (t) supplied to the two inputs of the adder 27.1 (27.2) are compensated at its output.

Consequently, a false signal (interference) u _p (t) received through the direct channel at a frequency ω _p = ω _pr2 is suppressed using a filter plug, consisting of a narrow-band filter 25.1 (25.2), a phase inverter 26.1 (26.2), an adder 27.1 (27.2) and implementing the phase compensation method.

Thus, the proposed device, in comparison with the prototype and other technical solutions of a similar purpose, provides increased selectivity, noise immunity and reliability of duplex radio communication between the monitoring and control point and each geographically distributed object. This is achieved by suppressing spurious signals (interference) received on the first ω _З1 and second ω _З2 mirror channels, on the first ω _К1 , second ω _К2 , third ω _К3 , fourth ω _К4 Raman channels and direct channel at a frequency ω _п = ω _pr2 .

Moreover, to suppress false signals (interference) received via mirror and combined channels, frequency selectors are used, made in the form of oscillatory circuits and realizing the resonance phenomenon.

It should be noted that the resonance phenomenon is a fundamental principle of operation of many systems and devices of radio electronics.

To suppress false signals (interference) received via the direct channel, a filter plug is used that implements a phase compensation method.

Claims (2)

1. A regional communication information system containing radio stations installed at a monitoring and control point and each geographically distributed object, each radio station being made in the form of a series-connected source of analog messages, an amplitude modulator, the second input of which is connected to the output of the carrier frequency generator, phase a manipulator, the second input of which is connected to the output of the source of discrete messages, the first mixer, the second input of which is connected to the output of the first local oscillator, an amplifier of the first intermediate frequency, a first power amplifier, a duplexer, the input-output of which is connected to the transceiver antenna, a second power amplifier, a second mixer, the second input of which is connected to the output of the second local oscillator, and an amplifier of the second intermediate frequency, serially connected amplitude limiter, synchronous detector and a recording and analysis unit connected in series to the output of the amplitude limiter of the multiplier, the second input of which is connected to the output of the first local oscillator, filter and phase detector, the second input of which is connected to the output of the second local oscillator, and the output is connected to the second input of the recording and analysis unit, characterized in that each radio station is equipped with two narrow-band filters, a phase inverter, an adder, a frequency selector, an amplitude detector, a threshold block and key, and to the output of the second power amplifier is connected in series with the first narrow-band filter, phase inverter, adder, the second input of which is connected to the output of the second power amplifier, selectively frequency, a second input coupled to an output of the first oscillator, a second narrow-band filter, an amplitude detector, a threshold unit, and a key, a second input coupled to the amplifier output a second intermediate frequency, and an output connected to the input of the amplitude limiter and the second input of the synchronous detector, the frequency ω settings _{n3 of the} first narrow-band filter is chosen equal to the second intermediate frequency ω _pr2 ω _n3 = ω _pr2 , the tuning frequency is ω _{n1 of the} frequency selector and the second narrow-band filter of the radio station installed at control and control, it is chosen equal to the frequency ω _{g1 of the} first local oscillator and the frequency ω _{2 of the} received signal ω _n1 = ω _g1 = ω ₂ , which corresponds to the resonance phenomenon. 2. The regional communication information system according to claim 1, characterized in that the tuning frequency ω _{n2 of the} frequency selector and the second narrow-band filter of the radio station installed at each geographically distributed object is chosen equal to the frequency ω _{g2 of the} first local oscillator and the frequency ω _{1 of the} received signal ω _n2 = ω _g2 = ω ₁ , which corresponds to the resonance phenomenon.

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