RU2450363C2 - Method of identifying objects and apparatus for realising said method - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: apparatus for identifying objects, which realises the disclosed method, has a transponder 1 with an antenna 2 mounted on the object 3, a receive-transmit channel 4 with an antenna 5, a threshold device 6 and an information processing unit 7.

EFFECT: high selectivity and noise immunity of the receiving channel by suppressing spurious signals received over image and combinational channels.

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Description

The proposed method and device relate to the identification of objects, mainly large ones, for example food containers, and can be used in various industries, in particular, for monitoring and tracking the movement of cargo, container and traffic flows in accordance with data on the quality condition and the coordinates of burial sites, depending on the degree of radiation infection, as well as for the implementation of guard systems, passportization devices in a large range of distances ings from the object under normal and adverse environmental conditions.

Known methods and devices for identifying objects (author's certificate. USSR No. 1.627.832, RF patents No. 2.057.334, 2.098.297, 2.126.980, 2.267.158, 2.292.587, 2.371.734; US patents No. 4.096.477 , 4.625.208, 6.639.509, 7.119.732; French patent No. 2.630.236; Gauche J. SAW device - the basis of a vehicle identification system. Electronics, 1990, issue 9, etc.).

Of the known methods and devices closest to the proposed are the "Method of identification of objects and installation for its implementation" (RF patent No. 2.057.334, G01N 33/02, 1991), which are selected as prototypes.

The known method and device is based on the radiosounding of an object on which a piezoelectric passive transponder is mounted with an antenna and a receiving-transmitting path by irradiating a passive transponder with a radio signal, generating a codeword containing an information part with data about the object, for example, production and implementation time, quality indicators and etc. Then the generated electrical signal is re-emitted with its subsequent reception by the antenna of the transmitting and receiving tract. The sounding of the object is carried out by a harmonic signal, and along with the information part, a pilot signal is introduced into the codeword, which is separated from the information part by a fixed time interval, while the information part is encoded by biphasic modulation of elementary symbols, and the codeword is decrypted by phase synchronization.

The receiving path of the installation, which implements the known method, is built according to a superheterodyne circuit in which the same value of the intermediate frequency w _up can be obtained by receiving signals at two frequencies w _c and w _з , i.e.

w _up = w _c -w _g , w _up = w _g -w _s .

Consequently, if w _c tuning frequency taken as the main receiving channel, along with it will be a mirror receiving channel frequency w _of which differs from the frequency w _c at 2w _up and positioned symmetric (mirrored) with respect to the local oscillator frequency w _r (FIG. 2). Conversion on the mirror channel of the reception occurs with the same conversion coefficient K _ol as on the main channel. Therefore, it most significantly affects the ingenuity and noise immunity of the receiving path.

In addition to the mirror, there are other additional (combinational) reception channels. In general terms, any combination receive channel takes place when the following conditions are met:

w _up = (± mw _ki ± nw _g ),

where w _кi is the frequency of the i-th Raman reception channel;

m, n, i are positive integers.

The most harmful combinational reception channels are those generated by the interaction of the first harmonic of the signal frequency with the harmonics of the frequency of the local oscillator of the small order (second, third, etc.), the sensitivity of the receive path through these channels is close to the sensitivity of the main channel. So, two combination channels with m = 1 and n = 2 correspond to frequencies:

w _k1 = 2w _g -w _up and w _k2 = 2w _g + W _up ,

where 2w _g is the second harmonic of the local oscillator frequency.

The presence of false signals (interference) received through the mirror and Raman channels, leads to a decrease in selectivity and noise immunity of the receiving path.

An object of the invention is to increase the selectivity and noise immunity of the receiving path by suppressing false signals (interference) received via mirror and Raman channels.

The problem is solved in that the method of identifying objects, mainly large-sized cargo containers for food, providing, in accordance with the closest analogue, securing to the object a piezoelectric passive transponder with an antenna, radio sounding the object with a receiving and transmitting path by irradiating the passive transponder with a radio signal, generating a code word containing the information part with data on the object, for example, the time of manufacture and sale, quality indicators, re radiation of the generated electrical signal and its subsequent reception by the antenna of the transmitting and receiving tract and decoding information to obtain data about the object, while the sounding of the object is carried out by a harmonic signal, and along with the information part, a pilot signal is introduced into the code word, which is separated from the information part by a fixed the time interval, the coding of the information part is carried out by biphasic modulation of elementary symbols, and the codeword is decrypted by means of phases howl timing differs from the closest analog by the fact that the reception signal reradiated performed in two channels, in which the reradiated signal is converted in frequency, using two oscillators whose frequencies w and w _{r1 r2} which spread to twice the value of the intermediate frequency

w -w _{r2 r1} = 2w _up

and choose symmetric with respect to the frequency w _{c of the} main receiving channel

w _c -w _g1 = w _g2 -w _c = w _up ,

isolate the intermediate frequency voltage, subject them to correlation processing, isolate the voltage proportional to the correlation function R (τ), compare it with the threshold voltage and, if it is exceeded, allow further processing of the reradiated intermediate frequency signal.

The problem is solved in that the installation for identifying objects, including, in accordance with the closest analogue, a passive transponder mounted on the object with an antenna, made on the basis of a single-input transducer of surface acoustic waves, forming a code word and containing a piezoelectric sound duct and located on its surface in the main acoustic channel basic and information taps carrying data about the object, connected by electric buses, as well as a transmitting and receiving path with an antenna for radio sounding of the object, a threshold device and an information processing unit with an indication device, the one-input surface acoustic wave transducer included in the passive transponder additionally has a tap forming a pilot signal, additional, information and base taps are located on the surface of the piezoelectric sound duct relative to each other so that the intrinsic noise of the passive transponder, preferably signals of two and three passage, fall into free from information about the object, the codeword zone, the threshold device contains a pilot signal selector, a phase detector with a phase-locked loop, equipped with a key for installing a controlled voltage generator at the time of arrival of the pilot signal, and a memory element for holding the controlled voltage generator at the time of arrival of the information part code word, the receiving path contains a preselector, a radio frequency amplifier, a first mixer, the second input of which is connected in series to the output of the antenna switch connected to the output of the first local oscillator, the first main selection filter and the first intermediate frequency amplifier, differs from the closest analogue in that the receiving path is equipped with a second mixer, a second local oscillator, a second main selection filter, a second intermediate frequency amplifier, a correlator, a threshold block and a key, a second mixer is connected in series to the output of the radio frequency amplifier, the second input of which is connected to the output of the second local oscillator, the second filter of the main selection, the second amplifier is between current frequency, a correlator, the second input of which is connected to the output of the first intermediate frequency amplifier, a threshold block and a key, the second input of which is connected to the output of the first intermediate frequency amplifier, and the output is connected to the first input of the phase detector.

The structural diagram of the installation for the identification of objects is presented in figure 1. Frequency diagrams illustrating the formation of additional receiving channels are shown in FIGS. 2 and 3. The design of a passive transponder based on a single-input transducer of surface acoustic waves is shown in FIG. 4. The fine structure of the transducer taps is shown in FIG. 5.

The facility for identifying objects comprises a transponder 1 with an antenna 2, mounted on an object 3, a transmit-receive path 4 with an antenna 5, a threshold device 6 and a unit 7 for processing information. The structure of the defendant 1 includes an antenna 2, a multifunction converter, which is a single-input transducer 8 of surface acoustic waves and a device 9 matching the transducer 8 and antenna 2, based on a microwave transformer.

The composition of the transmitting and receiving tract includes an antenna 5, an antenna switch 10, a receiving 11 and transmitting 12 paths.

The receiving path 11 contains a preselector 13 connected in series to the output of the antenna switch 10, a radio frequency amplifier 14, a first mixer 16, a second input of which is connected to the output of the first local oscillator 17, a first main selection filter 18, a first intermediate frequency amplifier 19 and a key 58 connected in series to the output of the radio frequency amplifier 14, the second mixer 52, the second input of which is connected to the output of the second local oscillator 53, the second main selection filter 54, the second intermediate frequency amplifier 55, the correlator 56, the second input One of which is connected to the output of the first intermediate frequency amplifier 19, and a threshold unit 57, the output of which is connected to the second input of the key 58.

The transmitting path 12 contains serially connected master oscillator 20 with quartz stabilization, a digitally controlled key 21, a frequency multiplier 22 and a power amplifier 23, the output of which is connected to the input of the antenna switch 10.

The threshold device 6 contains a phase detector 24, an RC low-pass filter 28, a varicap 26, an analog key 29, an analog memory element 27 and a controlled oscillator 25, the output of which is connected to the second input of the phase detector 24, as well as a selector, connected in series to the output of the key 58 30 pilot signals.

The information processing unit 7 contains a voltage comparator 31 with a two-level potential output, an asynchronous register 32 with a serial input and a parallel output, a microcontroller 33, which includes an information input / output device 34, a computing device 35 with memory, an indication device 36, a keyboard 37 , a multiphase generator 38 pulses to control the operating modes of the device.

The design of the multifunction transponder 1, made on the basis of a single-input transducer of surface acoustic waves and located on the piezoelectric sound pipe 39, is shown in Fig.4. Schematically, the transducer consists of two acoustic channels: the main 40 and additional 41, in which the functional transformation of information occurs. The supply and removal of signals from the converter is carried out using electric buses 42 and 43, respectively, for the main channel and 43 and 44 for the additional channel. The main channel consists of a base tap 45, tap 46, designed to generate a pilot signal and information tap 47. The additional channel consists of topologically inverse taps 46 and 47, respectively, taps 48 and 49.

The number M of information taps is determined by the number N of elementary symbols (premises) τ _e QPSK signal, which is identical to the number of bits of the required binary code. In turn, M determines the intervals between the taps and the maximum size of the structure along the propagation axis of the surfactant, which is associated with the need to neutralize the parasitic effect of signals of two and three passage on the pulse characteristic of the converter.

The total length of the information bends

l _s ML _c ,

where l _c is the distance between the information taps.

The value of l _c is determined by the duration τ _{e of the} elementary symbol.

The fine structure of the taps is shown in FIG. 5, which shows that all types of taps are equidistant interdigital structures with a repetition period of pins 50 equal to the length of the surfactant λ. Moreover, if S, m, n is the number of electrode pairs in the branches of type 45 (a), 46 (b), 47 (c), respectively, then the lengths of the branches are equal to:

l _a S · λ, l _b m · λ ,, l _c n · λ,

where l _a , l _b , l _c - the distance between the information taps of type 45 (a), 46 (b), 47 (c), respectively.

The transmit-receive path has the following operating modes:

- a simulation mode designed to check the electronic structures of the installation;

- search mode designed to probe the space with low-power radio signals;

- a polling mode intended for guaranteed reading of information about an object by radio signals of higher power.

The simulation mode is carried out generated on the key 21 using the control signals of the control PSK signal.

The search mode is used in the case of an unknown location of the object to obtain information of the form “There is an object” / “No object”. Such a decision is made in the selector 30 for analysis of the duration and amplitude of the pilot signal and allows to reduce the power of the harmonic sounding radio signal in K times.

The polling mode is basic. In contrast to the search mode, the harmonic sounding radio signal here has a greater power, and therefore the amplitude of the pilot signal increases, which allows the information processing unit 7 together with the threshold device 6 to set and remember the phase at the time of arrival of the PSK signal. As a result, the envelope is extracted from the PSK signal by the phase detector 24, and after the comparator 31, a serial binary code of the received message is obtained. Next, on the asynchronous register 32, the serial code is converted to parallel in real time.

The reading process is possible when overlapping radiation patterns of antennas 2 and 5, respectively. In this case, the harmonic sounding radio signal excites an electric signal on antenna 2, which, through the matching circuit 9, falls on a single-input converter 8. Acting on taps of the form 45-47, the electric signal excites surface acoustic waves in the X direction in the X direction, which, in turn, the radio signals are excited due to the inverse piezoelectric effect on the taps encountered during the propagation of the taps. Radio signals induced on electric buses can be useful and false, and the total signal represents their superposition.

So, in addition to the useful signals obtained as a result of the interaction of the taps 45, 46 and 45, 47 and representing the pilot signal and the PSK signal, respectively, parasitic signals of two and three times passing as a result of the interaction of the same taps, as well as the signal as a result of the interaction of taps 46 and 47.

In addition, in the main channel 40, false signals are generated resulting from the interaction between the electron pairs within these groups of taps. Compensation of the effects of signals of two and three times the passage occurs due to their allocation in free from the useful signal time zones, as a result of the selection of the corresponding spatial intervals between the taps (figure 4). Compensation of the influence of spurious signals is carried out by introducing an additional acoustic channel 41, in which as a result of the interaction of inverse taps 48 and 49, impulse responses are formed that are out of phase with respect to the main channel. In this case, compensation occurs due to the mutual destruction of spurious signals.

Therefore, after a superposition, a useful signal is generated on the converter electric buses 42 and 44.

u _c (t) = U _c · Cos [w _c t + φ _к (t) + φ _с ], 0≤t≤T _c ,

where U _c , w _c , φ _s , T _s - amplitude, carrier frequency, initial phase and signal duration;

φ _к (t) = {0, π} is the manipulated component of the phase that displays the law of phase manipulation in accordance with the modulating code M (t), and φ _к (t) = const for Кτ _э <t <(к + 1) τ _e and can change abruptly at t = Kτ _e , i.e. at the borders between elementary premises (symbols) (K = 1, 2, ..., N-1);

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

The modulating code M (t) is the identification code of the object 3 on which the transponder 1 is installed.

The generated QPSK signal is re-emitted by antenna 2 into space, captured by the transceiver antenna 5, and through the antenna switch 10, the preselector 13 and radio frequency amplifier 14 is fed to the first inputs of the mixers 16 and 52. The preselector 13 serves to coordinate the receiver with the antenna and suppress signals outside the operating range frequencies. The radio frequency amplifier 14 has a low level of intrinsic noise and a large dynamic range due to a sharp change in the signal level when changing the distance to the object. The second inputs of the mixers 16 and 52 are supplied with the voltage of the local oscillators 17 and 53, respectively:

u _g1 (t) = U _g1 · Cos (w _g1 t + φ _g1 ),

u _g2 (t) = U _g2 Cos (w _g2 t + φ _g2 ),

where U _g1 , U _g2 , w _g1 , w _g2 , φ _g1 , φ _g2 are the amplitudes, frequencies, and initial phases of the local oscillator voltages 17 and 53.

Moreover, the frequencies w _g1 and w _g2 local oscillators are spaced at twice the intermediate frequency:

_r2 w -w _gl = 2w _up

and are selected symmetric with respect to the frequency w _{c of the} main receiving channel (Fig.3):

w _c -w _g1 = w _g2 -w _c = w _up .

This circumstance leads to a doubling of the number of additional receiving channels, but creates favorable conditions for their suppression due to the correlation processing of channel voltages.

At the output of the mixers 16 and 52, voltages of combination frequencies are generated. Amplifiers 19 and 55 are allocated voltage intermediate (differential) frequency:

u _up1 (t) = U _pr1 · Cos [w _up t + φ _к (t) + φ _up1 ],

u _up2 (t) = U _pr2 · Cos [w _up2 t-φ _к (t) + φ _up2 ], 0≤t≤T _c ,

where U _CR1 = ½U _c · U _g1 - the amplitude of the first voltage of the intermediate frequency;

U _up2 = ½U _c · U _r2 - voltage amplitude of the second intermediate frequency;

w _up = w _c -w _g1 = w _g2 -w _c - second intermediate (difference) frequency;

φ _up1 = φ _s -φ _g1 - the initial phase of the first intermediate frequency voltage;

φ _up2 = φ _c -φ _r2 - the initial phase of the second intermediate frequency voltage; which go to the two inputs of the correlator 56. At the output of the correlator 56, a voltage U (τ) is generated proportional to the correlation function R (τ), which is compared with the threshold voltage U _then in the threshold block 57. The threshold level U _{then is} exceeded only at the maximum voltage U _max (τ) proportional to the correlation function R (τ).

It should be noted that the correlation function R (τ) of FMN signals has a remarkable property: it has a pronounced main lobe and a relatively low level of side lobes.

The voltage U _max (τ) corresponding to the main lobe of the correlation function R (τ) exceeds the threshold level U _pores in the threshold block 57. This is because the channel voltages U _up1 (t) and U _up2 (t) are formed by the same useful FMN signal received on two channels at the same frequency w _c , therefore, there is a strong correlation between the indicated channel voltages. The voltage U _max (τ) proportional to the correlation function R (τ) reaches its maximum value and exceeds the threshold level U _pores in the threshold block 57. When the threshold level U _pores is exceeded, a constant voltage is generated in the threshold block 57, which is supplied to the key control input 58 and opens it. In the initial state, the key 58 is always closed.

In this case, the voltage U _up1 (t) from the output of the intermediate frequency amplifier 19 through the public key 58 is supplied to the first (information) input of the phase detector 24, and the reference voltage is supplied to the second (reference) input from the output of the generator 25

u ₀ (t) = U ₀ Cos (w _up t + φ _up1 ),

where U ₀ is the amplitude of the reference voltage.

As a result of synchronous detection, a low-frequency voltage is generated at the output of the phase detector 24

u _n (t) = U _n · Cosφ _k (t), 0≤t≤T _c ,

where U _n = ½U _CR1 · U ₀ - the amplitude of the low-frequency voltage,

proportional to the modulating code M (t), which is received for further processing.

If a false signal (interference) is received through the first mirror channel at a frequency w _s1 , then in frequency converters 15 and 51 it is converted to the voltage of the following frequencies:

w _up = w _g1 -w _z1 , 3w _up = w _g2 -w _z1 .

However, only a voltage with a frequency w _up falls into the passband of an intermediate-frequency amplifier 19, the voltage of the correlator 56 is zero, the key 58 does not open, and a false signal (interference) received through the first mirror channel at a frequency w _s1 is suppressed.

For a similar reason, false signals (interference) received on the second mirror channel at a frequency w _s2 and on any other additional channel are also suppressed.

However, if the spurious signals (interference) are received simultaneously, for example, the first _P1 and second w w mirror _s2 channels, the amplifiers 19 and 55 the following voltages are allocated:

u _up3 (t) = U _pr3 Cos (w _up t + φ _up3 ),

u _up4 (t) = U _CR4 · Cos (w _up t + φ _up4 ), 0≤t≤T _s ,

where U _PR3 = ½U _P1 · _r1 U - amplitude of the third intermediate frequency voltage;

U _WP4 = ½U _s2 · U _r2 - the amplitude of the voltage of the fourth intermediate frequency;

w _up = w -w _{gl P1} = w -w _{s2 r2;}

φ _up3 = φ _g1 -φ _z1 - the initial phase of the third voltage of the intermediate frequency;

φ _up4 = φ _z2 -φ _g2 - the initial phase of the fourth voltage of the intermediate frequency;

which enter the two inputs of the correlator 56, respectively. But the key 58 in this case does not open. This is because different false signals (interference):

u _З1 (t) = U _Зl · Cos (w _З1 t + φ _З1 ),

u _z2 (t) = U _z2 Cos (w _z2 t + φ _z2 ),

where U _Z1 , U _Z2 , w _Z1 , w _Z2 , φ _Z1 , φ _Z2 are the amplitudes, frequencies and initial phases of the false signals (interference) received on the first and second mirror channels,

are taken at different frequencies _wz1 and _wz2 ; therefore, there is a weak correlation between the channel voltages U _up3 (t) and U _up4 (t). In addition, the correlation function of interference does not have a pronounced main lobe, as is the case with complex PSK signals. In this case, the output voltage of the correlator does not exceed the threshold level U _then in the threshold block 57, the key 58 does not open, and false signals (interference) received simultaneously on the first w _З1 and second w _З2 mirror channels are suppressed. For a similar reason, other false signals (interference) received simultaneously on two other additional channels are suppressed.

In this technical solution, the use of phase synchronization is a way to reduce the effect of re-reflections of the probing radio package from local objects, as well as the spurious effects of industrial and radio interference in the operating frequency range. In this case, the random position of the interference phase is taken into account, and therefore, the determinate phase position used in the case of biphasic modulation of the response signal is used in the codeword.

To ensure reliable synchronization of the QPSK signal, an additional signal with a known phase is required. In this case, the pilot signal included in the response codeword is used as such a signal. To simplify the binding due to the use of natural frequencies, the time interval between the pilot signal and the information part of the code word is given as a multiple of the center frequency period. In time, the pilot signal may follow before and after the information part of the codeword. In the first case, the area of the sound duct is used more effectively, in the second there is an additional opportunity to reduce the effect of reflections from local objects.

The spurious interaction of the information taps and the tapping that forms the pilot signal is compensated for in the installation using an additional acoustic channel. Structurally, the additional channel is identical to the main one, except for the missing base tap, in connection with which only the above-mentioned interference signals are formed in it. Thus, choosing the polarity of the taps of the auxiliary channel depending on the type of electrical connection to the main channel, the parasitic can be subtracted from the full signal at the output electric buses.

Given the work of the defendant in the time domain, it is possible to exclude the influence of signals of two and three passage on the operation of the installation by choosing the intervals between taps so that the interference falls into areas free of useful information before or after the information part of the code word with subsequent suppression in the receiving path due to organization time references.

The use of the proposed technical solutions improves the noise immunity of the installation, operating in environmentally unfavorable conditions with active and passive interference, reflections from local objects, increase the reading range and the reliability of its operation through the use of new circuitry solutions for the transmitting and receiving path, introducing an additional acoustic channel into the SAW converter , phase locking method by including a pilot signal in the codeword, modulation method useful Igna and suppression of spurious signals (noise) received by the mirror and Raman channels. Moreover, to suppress these false signals (interference), a two-channel reception method is used in which the frequencies w _g1 and w _{g2 of the} local oscillators of the two channels are separated by twice the intermediate frequency

w -w _{r2 r1} = 2w _up

and choose symmetric with respect to the frequency w _{c of the} main receiving channel

w _c -w _g1 = w _g2 -w _c = w _up .

This circumstance leads to a doubling of the number of additional receiving channels, but creates favorable conditions for their suppression by correlation processing of channel voltages.

In turn, the use of phase synchronization by a pilot signal reduces the PLL requirement and reduces the duration of elementary symbols in the received biphasic code, which allows for a fixed dimensions of the sound pipe to increase the information capacity of the transponder and, therefore, increase the number of recognizable objects.

Claims (2)

1. A method for identifying objects, mainly bulky cargo containers for food, providing for fastening a piezoelectric passive transponder with an antenna to the object, radio sounding the object with a transmitting and receiving path by irradiating the passive transponder with a radio signal, generating a code word containing an information part with data about the object, for example, the time of manufacture and implementation, quality indicators, re-radiation of the generated electrical signal and its subsequent the antenna of the transmitting and receiving tract and decoding information to obtain data about the object, while the sounding of the object is carried out by a harmonic signal, and along with the information part, a pilot signal is introduced into the codeword, which is separated from the information part by a fixed time interval, the information part is encoded by biphasic modulation of elementary symbols, and the codeword is decrypted by phase synchronization, characterized in that the reception of the re-emitted signal carried out in two channels in which the re-emitted signal is converted in frequency using two local oscillators, the frequencies w _g1 and w _{g2 of} which are separated by twice the intermediate frequency
w -w _{r2 r1} = 2w _up
and choose symmetric with respect to the frequency w _{c of the} main receiving channel
w _c -w _g1 = w _g2 -w _c = w _up ,
isolate the intermediate frequency voltage, subject them to correlation processing, isolate the voltage proportional to the correlation function R (τ), compare it with the threshold voltage and, if it is exceeded, allow further processing of the reradiated intermediate frequency signal. 2. Installation for identifying objects, including a passive transponder attached to the object with an antenna, made on the basis of a single-input transducer of surface acoustic waves, forming a code word and containing a piezoelectric sound guide and basic and information taps located on its surface in the main acoustic channel carrying data about the object connected by electric buses, as well as a transmitting and receiving path with an antenna for radiosounding an object, a threshold device and an in processing unit formations with a device for indicating, the one-input transducer of surface acoustic waves, which is part of the passive transponder, additionally has a tap that generates a pilot signal, additional, informational and basic taps are located on the surface of the piezoelectric sound duct relative to each other so that the intrinsic noise of the passive transponder , preferably the signals of two and three passage pass into the codeword zone free of information about the object, the threshold device contains a pilot signal selector, a phase detector with a phase-locked loop, equipped with a key for installing a controlled voltage generator at the time of arrival of the pilot signal, and a memory element for holding the controlled voltage generator for the time of arrival of the information part of the code word, the receiving path contains serially connected to the output antenna switch preselector, radio frequency amplifier, first mixer, the second input of which is connected to the output of the first local oscillator, the first filter of the main selection The method is characterized in that the receiving path is equipped with a second mixer, a second local oscillator, a second main selection filter, a second intermediate frequency amplifier, a correlator, a threshold block and a key, and a second mixer is connected in series to the output of the radio frequency amplifier, the second input of which is connected to the output of the second local oscillator , a second filter of the main selection, a second intermediate frequency amplifier, a correlator, the second input of which is connected to the output of the first intermediate frequency amplifier, a threshold block and cells yuch, the second input of which is connected to the output of the first intermediate frequency amplifier, and the output is connected to the first input of the phase detector.

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