RU2030750C1 - Panoramic receiver - Google Patents

Abstract

FIELD: measurement technology. SUBSTANCE: panoramic receiver has aerial 1, two sweep generators 2, 33, heterodyne 3, mixer 4, intermediate frequency amplifier 5, detector 6, scale-of-eight multiplier 7, four meters 8, 9, 21, 22 of spectrum width, three comparators 10, 23, 24, three threshold units 11, 25, 26, key 12, delay line 13, multiplier 14, n band-pass filters (15₁-15_n), n amplitude detectors (16₁-16_n), n videoamplifiers (17₁-17_n), n cathode-ray tubes (18₁-18_n), scale-of-four frequency multiplier 19, scale-of-two frequency multiplier 20, three analog-to-code converters 27, 28, 29, indicator 30, amplitude detector 31, frequency detector 32, cathode-ray tube 34. EFFECT: enhanced efficiency of search and detector of phase-shifted signals and of visual estimation of their principal parameters. 3 dwg

Description

 The invention relates to radio engineering and can be used to search and detect phase-shifted signals (PSK), as well as their main parameters.

Of the known devices, the closest to the proposed one is a panoramic receiver, selected as a prototype. The specified receiver provides the search and detection of phase-shifted signals, as well as a visual assessment of their carrier frequency. However, it does not make it possible to evaluate other parameters of the detected PSK signal, as well as the multiplicity m and the law of phase manipulation, the signal duration T _s , the duration τ _n and the number N of the chips that make up the signal T _c = N ˙ τ _n .

 The technical result in the implementation of the invention is to expand the functionality of the device by visually evaluating the main parameters of the detected PSK. This is achieved by the fact that in the device containing the receiving antenna in series, a mixer, the second input of which is connected through the local oscillator to the first output of the first sweep generator, an intermediate frequency amplifier, an eight frequency multiplier, a second spectral width meter, the first comparison unit, the second input of which through the first spectral width meter connected to the output of the intermediate frequency amplifier, the first threshold block, a key, the second input of which is connected to the output of the intermediate frequency amplifier, a line costs, a multiplier, the second input of which is connected to the output of the key, and n-processing channels, each of which consists of a series-connected bandpass filter, an amplitude detector, a video amplifier, and a vertical electrode of a cathode ray tube, the horizontal electrode of which is connected to the second output of the first scan generator , introduced a frequency multiplier by four, a frequency multiplier by two, the third and fourth meters of the width of the spectrum, the second and third comparison blocks, the second and third threshold blocks, three converters an analog-code indicator, an indicator, an (n + 1) -th amplitude detector, a frequency detector, a second scan generator and an (n + 1) -th cathode ray tube, and the first analog-code converter is connected in series to the output of the first threshold block and indicator, the output of the intermediate frequency amplifier is connected in series with a four frequency multiplier, a third spectral width meter, a second comparison unit, the second input of which is connected to the output of the first spectrum width meter, a second threshold block and a second analog converter the code, the output of which is connected to the second input of the indicator, to the output of the intermediate frequency amplifier there are connected in series a frequency multiplier for two, a fourth measuring instrument for spectral width, a third comparison unit, a second input for which is connected with the output of the first measuring instrument for spectral width, a third threshold unit and a third analog converter the code, the output of which is connected to the third input of the indicator, the (n + 1) -th amplitude detector, the second scan generator, and the horizontal electrode of the (n + 1) -th electronic uchevoy tube, wherein a vertical electrode through a frequency detector coupled to an output key.

 In FIG. 1 shows a block diagram of a device; figure 2 is a view of the possible waveforms; figure 3 is a timing diagram explaining the operation of the device.

The panoramic receiver comprises an antenna 1, a first sweep generator 2, a local oscillator 3, a mixer 4, an intermediate frequency amplifier 5, a detector 6, an eight frequency multiplier 7, a first 8 and a second 9 spectral width meters, a first comparison unit 10, a first threshold unit 11, key 12, delay line 13, multiplier 14, band-pass filters 15 ₁ N15n, amplitude detectors 16 ₁ N16n, video amplifiers 17 ₁ N17n, cathode ray tubes (CRT) 18 ₁ N18n, frequency multiplier 19 by four, frequency multiplier 20 by two, third 21 and fourth 22 meters of the width of the spectrum, the second 23 and tr there are 24 comparison blocks, second 25 and third threshold blocks, first 27, second 28 and third 29 analog-code converters, indicator 30, (n + 1) -th amplitude detector 31, frequency detector 32, second sweep generator 33 and (n +1) CRT 34. Moreover, the mixer 4 is connected in series to the output of the antenna 1, the second input of which is connected through the local oscillator 3 to the first output of the sweep generator 2, an intermediate frequency amplifier 5, an eight frequency multiplier 7, a spectral width meter 9, block 10 comparison, the second input of which through the meter 8 of the spectrum width soy inen with the output of the intermediate frequency amplifier 5, the threshold block 11, key 12, the second input of which is connected to the output of the intermediate frequency amplifier 5, a delay line 13, a multiplier 14, the second input of which is connected to the output of the key 12 and n processing channels, each of which consists from a series-connected bandpass filter 15i, an amplitude detector 16i, a video amplifier 17i and a vertical CRT electrode 18i, the horizontal electrode of which is connected to the second output of the scan generator 2. The output of the intermediate frequency amplifier 5 is connected in series to a four frequency multiplier 19, a spectral width meter 21, a comparison unit 23, the second input of which is connected to the output of the spectral width meter 8, a threshold block 25, an analog code converter 28 and an indicator 30, the second input of which through the converter 27, an analog code is connected to the output of the threshold unit 11, the frequency multiplier 20 by two, the spectral width meter 22, the comparison unit 24, the second input of which is connected to the output of the intermediate frequency amplifier 5 is dined with the output of the spectral width meter 8, the threshold unit 26 and the analog code converter 29, the output of which is connected to the third input of the indicator 30. An amplitude detector 31, a sweep generator 33, and a horizontal CRT electrode 34 are connected in series with the vertical electrode through the frequency detector 32 is connected to the output of the key 12.

 Panoramic receiver operates as follows.

The specified frequency range Df is viewed with the help of a sweep generator 2, which periodically with a sawtooth law tunes the local oscillator frequency 3. At the same time, sweep generator 2 generates a horizontal scan of a CRT 18 ₁ N18n, which is used as the frequency axis, and its length corresponds to the frequency span range Df. The key 12 in the initial state is always closed.

- скорость изменения частоты гетеродина (скорость изменения первой гармоники частоты гетеродина).Received QPSK signal
U _c (t) = V _c ˙cos [ω _c t + φ _k (t) + φ _c ],
0 ≅t≅ T _c , where V _c , ω _c , T _c , φ _c - amplitude, carrier frequency, duration and initial phase of the signal;
φ _k (t) is the manipulated phase component that displays the phase manipulation law in accordance with the modulating code M (t) (Fig. 3a), and φ _k (t) = const for K τ _and <t <(K + 1) τ _n and can change abruptly by Δφ for t = K τ _n i.e. at the boundaries between elementary premises (K = 1, 2, ..., N-1);
τ _n N is the duration and number of chips that make up the signal with a duration of T _s (T _s = N ˙τ _n ); from the output of the antenna 1 is supplied to the first input of the mixer 4, to the second input of which the voltage of the local oscillator 3 of a ramp frequency
U _g (t) = V _g ˙cos (ω _g t + πγ ₁ t ² + φ _g ),
0 ≅t≅ T _n where V _g , ω _g , T _p , φ _g - amplitude, initial frequency, repetition period and initial phase of the local oscillator voltage;
γ ₁ =

- rate of change of the local oscillator frequency (rate of change of the first harmonic of the local oscillator frequency).

K₁·U_c·U_r;
К₁- коэффициент передачи смесителя;
ω_пр=ω_c-ω_г - промежуточная частота;
φ_пр= φ_c-φ_г - промежуточная начальная фаза; которое представляет собой сигнал с комбинированной линейной частотной модуляцией и фазовой манипуляцией (ЛЧМ-ФМн). Это напряжение поступает на вход обнаружителя 6, состоящего из умножителя 7 частоты на восемь, измерителей 8 и 9 ширины спектра, блока 10 сравнения, порогового блока 11 и ключа 12.At the output of the mixer 4, voltages of combination frequencies are generated. 5 is a voltage amplifier of intermediate (difference) frequency _pr1 U (t) = V _ave ˙cos [ω _ave t + φ _k (t) t ₁ ² -πγ +
_ave + φ], 0 ≅t≅ T _c, where V = _pr

K ₁ · U _c · U _r ;
To ₁ - gear ratio of the mixer;
ω _CR = ω _c -ω _g is the intermediate frequency;
φ _CR = φ _c -φ _g - intermediate initial phase; which is a signal with a combined linear frequency modulation and phase shift keying (LFM-PSK). This voltage is fed to the input of the detector 6, consisting of a frequency multiplier 7 by eight, meters 8 and 9 of the spectrum width, block 10 comparison, threshold block 11 and key 12.

, π,,

π], 8 φ_k (t) = 0,2 π, 4 π, 6 π, 8 π, 10 π, 12 π, 14 π при приеме сигнала с трехкратной фазовой манипуляцией [ТФМ_н, φ_k (t) = 0,

,

,

π, π,

π,

π,

π]. то в указанном колебании манипуляция фазы уже отсутствует.At the output of the frequency multiplier 17 by eight, a voltage is generated
U ₁ (t) = V _pr ˙cos [8ω _pr t-8πγ ₁ t ² +
+ 8φ _pr ], 0 ≅t≅ T _c . Since 8 φ _k (t) = 0.8 π when receiving a signal with a single phase shift keying [OFM _n , φ _k (t) = 0, π], 8 φ _k (t) = 0.4 π, 8 π, 12 π, when receiving a signal with double phase shift keying [DFM _n , φ _k (t) = 0,

, π ,,

π], 8 φ _k (t) = 0.2 π, 4 π, 6 π, 8 π, 10 π, 12 π, 14 π when receiving a signal with three-phase phase shift keying [TFM _n , φ _k (t) = 0 ,

,

,

π, π,

π,

π,

π]. then in the indicated oscillation phase manipulation is already absent.

f₈=

, тогда как ширина спектра Δ f_c ФМн-сигнала определяется длительностью τ_и его элементарных посылок

f_c=

, т.е. ширина спектра Δ f₈ восьмой гармоники сигнала в N раз меньше ширины спектра Δ f_c входного сигнала:

= N. Следовательно, при умножении частоты ФМн-сигнала на восемь его спектр "сворачивается" в N раз. Это и позволяет обнаружить ФМн-сигнал даже тогда, когда его мощность на входе приемника меньше мощности шумов.The width of the spectrum Δ f _{8 of the} eighth harmonic is determined by the duration T of _the signal

f ₈ =

, while the width of the spectrum Δ f _c FMN signal is determined by the duration of τ _and its elementary premises

f _c =

, i.e. the width of the spectrum Δ f _{8 of the} eighth harmonic of the signal is N times smaller than the width of the spectrum Δ f _{c of the} input signal:

= N. Therefore, when the frequency of the QPSK signal is multiplied by eight, its spectrum “folds” N times. This makes it possible to detect the PSK signal even when its power at the receiver input is less than the noise power.

The width of the spectrum Δ f _{from the} input QPSK signal is measured using meter 8, and the spectrum width Δ f _{8 of the} eighth harmonic of the signal is measured using meter 9. Voltages V and V ₈ proportional to Δ f _s and Δ f _8, respectively, from the outputs of meters 8 and 9 spectral widths are fed to two inputs of the comparison unit 10. Since V >> V ₈ , a positive voltage is generated at the output of the comparison unit 10, which exceeds the threshold level V _pores in the threshold block 11. The threshold level V _pores is selected so that it is not exceeded by random noise. When the threshold level V _pores is exceeded, a constant voltage is generated in the threshold block 11, which is supplied to the control input of the key 12, opening it.

K₂·U $\genfrac{}{}{0ex}{}{\text{2}}{\text{п}}$ _р;
К₂ - коэффициент передачи перемножителя 14;
ω_б1=2πγ₁τ_з - частота биений;
φ_k1(t)=φ_k(t-τ_з)-φ_k (t).In this case, the voltage U _pr1 (t) from the output of the intermediate frequency amplifier 5 through the public key 12 is simultaneously supplied to the first input of the multiplier 14 and to the input of the delay line 13, at the output of which a voltage is generated
U _pr2 (t) = U _pr1 (t-τ) = V _pr ˙cos
[ω _ol (t-τ _s ) + φ _k (t-τ _s ) -πγ ₁ (t-τ _s ) ² +
_ave + φ], 0 ≅t≅ T _c, where τ _s - delay line of delay line 13. The output of the multiplier 14 is formed voltage
U ₁ (t) = V _b ˙cos [ω _b1 t + φ _k1 (t) -φ _b1 ],
0 ≅t≅ T _c , where U _b =

K ₂ · U $\genfrac{}{}{0ex}{}{\text{2}}{\text{P}}$ _p ;
To ₂ - the transfer coefficient of the multiplier 14;
ω _b1 = 2πγ ₁ τ _s - beat frequency;
φ _k1 (t) = φ _k (t-τ _з ) -φ _k (t).

φ _b1 = ω _pr τ _s + πγ ₁ τ _s ² . The carrier frequency of the beat voltage is ω _b1 = 2πγ ₁ τ _s = const. Therefore, for a fixed delay time τ _s , a multi-frequency beat signal is generated at the output of multiplier 14, the carrier frequency ω _{b1 of} which depends on the rate of change of the frequency γ _i (i = 1, 2, ... n) of the local oscillator 3. The rate of change of the frequency of the converted signal, coming to the input of the autocorrelator, depends on the harmonic number of the local oscillator frequency 3, interacting with the carrier frequency of the received PSK signal.

Bandpass filter tuning frequency 15 ₁ selectable
ω _n1 = ω _b1 = 2πγ ₁ τ _s , the tuning frequency of the bandpass filter 15 ₂ is selected
_2n ω = ω _b2 = 2πγ τ _{2 s,} and the tuning frequency of bandpass filter 15 is selected _n
ω _np = ω _bp = 2πγ _n τ _s , where γ _n = nγ ₁ is the rate of change of the nth harmonic of the local oscillator frequency. The voltage U _b i (t) from the output of the bandpass filter 15i is supplied to the input of the amplitude detector 16i, where it is detected and, after amplification in the video amplifier 17i, is applied to a vertical CRT electrode 18i, on the screen of which a pulse is generated (frequency mark). The position of the frequency mark on the horizontal scan of the CRT 18i uniquely determines the carrier frequency ω _{c of the} received PSK signal (Fig. 2a).

 Consequently, the harmonic number of the local oscillator frequency 3, with which the carrier frequency of the received PSK signal interacts, is determined by the number of the band-pass filter of that channel on the CRT screen of which a frequency mark is observed.

 To determine the multiplicity m of phase manipulation of the received QPSK signal, two additional processing channels are used, each of which consists of four (two) frequency multipliers 19 (20), a spectrum width meter 21 (22), and a comparison unit 23 (24), the second input of which is connected to the output of the spectral width meter 8, the threshold block 25 (26) and the analog-code converter 28 (29), the output of which is connected to the corresponding input of the indicator 30.

), тогда как ширина спектра Δ f_с ОФМн-сигнала определяется его элементарных посылок

f_c=

, т.е. ширина спектра указанных гармоник в N раз меньше ширины спектра входного сигнала

=

=

= N.If the receiver receives the OFMn signal [φ _k (t) = 0, π], then at the output of the frequency multipliers 7, 19 and 20, the following harmonic oscillations are generated by eight, four and two, respectively, U ₁ (t) = V _pr ˙cos (8ω _pr t-8πγ ₁ t ² + 8φ _pr ). U ₂ (t) = V _pr ˙cos (4ω _pr t-4πγ ₁ t ² + 4φ _pr ), U ₃ (t) = V _pr ˙cos (2ω _pr t-2πγ ₁ t ² + 2φ _pr ), 0 ≅ t≅ T _c . Since 8 φ _k (t) = 0.8 π; 4 φ _k (t) = 0.4 π; 2 φ _k (t) = = 0.2 π; then in the indicated oscillations the phase manipulation is already absent. The width of the spectrum of the eighth Δ f ₈ , the fourth Δ f ₄ and the second Δ f ₂ harmonics is determined by the signal duration Tc (Δ f ₈ = Δ f ₄ = Δ f ₂ =

), while the width of the spectrum Δ f _{with the} OFMn signal is determined by its elementary premises

f _c =

, i.e. the spectrum width of these harmonics is N times smaller than the spectrum width of the input signal

=

=

= N.

(t) = 0,

, π,

, то на выходе умножителей 7 и 19 частоты на восемь и четыре образуются гармонические колебания U₁(t) и U₂(t), т.е. в указанных каналах осуществляется свертка спектра входного сигнала, а на выходе умножителя 20 частоты на два образуется ОФМн-сигнал [ φ_k(t)=0,π,2π,2π]. Следовательно , на третьем входе индикатора 30 фиксируется логический "0", а на первом и втором - логические "1". Если на вход приемника поступает ТФМн-сигнал

(t) = 0,

,

,

π, π,

π,

π,

, то свертка спектра осуществляется только на выходе умножителя 7 частоты на восемь. При этом логическая "1" формируется только на первом входе индикатора 30. Следовательно по двоичному коду, зафиксированному индикатором 30, определяется кратность m фазовой манипуляции (величина скачков фазы Δφ) обнаруженного ФМн-сигнала (111 - m = 2, Δφ=π ; 110 - m = 4, Δφ =

; 100 - m = 8, Δφ =

).Consequently, when the frequency of the OFMn signal is multiplied by eight, four, and two, its spectrum “folds” N times. The width of the spectrum Δ f _{from the} input signal is measured using meter 8, the width of the spectrum of the eighth Δ f ₈ , fourth Δ f ₄ and second Δ f ₂ harmonics of the signal is measured using meters 9, 21 and 22. Voltages V ₈ , V ₄ and V ₂ proportional to Δ f ₈ , Δ f ₄ and Δ f ₂ respectively from the outputs of the meters 9, 21 and 22 of the spectrum width are supplied to the second inputs of the blocks 10, 23 and 24, the first inputs of which are supplied with the voltage V from the output of the meter 8 of the spectrum width, proportional Δ f _s Since V >> V ₈ , V >> V _n , V >> V ₂ , positive pulses are generated at the output of comparison blocks 10, 23 and 24, which exceed the threshold level V _pores in the threshold blocks 11, 25, 26 and are received to the inputs of the converters 27, 28, 29 analog code, the output of which is formed by a logical "1". The latter are registered by indicator 30. If a DPSK signal is input to the receiver

(t) = 0,

, π,

, then at the output of frequency multipliers 7 and 19 by eight and four harmonic oscillations U ₁ (t) and U ₂ (t) are formed, i.e. in the indicated channels, the convolution of the spectrum of the input signal is performed, and at the output of the frequency multiplier 20 by two, an OFMn signal [φ _k (t) = 0, π, 2π, 2π] is formed. Therefore, a logical “0” is fixed at the third input of the indicator 30, and logical “1” is fixed at the first and second. If the receiver receives the TPSK signal

(t) = 0,

,

,

π, π,

π,

π,

, then the convolution of the spectrum is carried out only at the output of the frequency multiplier 7 by eight. In this case, the logical “1” is formed only at the first input of the indicator 30. Therefore, the binary code fixed by the indicator 30 determines the multiplicity m of phase shift keying (the value of phase jumps Δφ) of the detected PSK signal (111 - m = 2, Δφ = π; 110 - m = 4, Δφ =

; 100 - m = 8, Δφ =

)

To estimate the duration T _{c of the} signal, the duration τ _n and the number N of the chips from which it is composed, an amplitude detector 31, a frequency detector 32, a sweep generator 33 and a CRT 34 are used.

The voltage U _pr1 (t) (Fig.3b) from the output of the intermediate frequency amplifier 5 through the public key 12 is simultaneously supplied to the inputs of the amplitude 31 and frequency 32 detectors. The amplitude detector 31 selects the envelope of the signal (figv), which is fed to the input of the sweep generator 33. In this case, the leading edge of the rectangular pulse starts, and the trailing generator 33 of the sweep closes. At the output of the latter, a sawtooth voltage is formed, which is used as the scan voltage and is fed to the horizontal electrode of a CRT 34.

At the output of the frequency detector 32, a voltage is generated proportional to the change in the frequency of the voltage U _pr1 (t) (Fig. 3d). At the same time, short bipolar pulses are formed at the top of this voltage, which correspond to the moments of an abrupt change in the phase of the received PSK signal (Fig. 3b).

 The generated voltage from the output of the frequency detector is supplied to a vertical CRT electrode 34, on the screen of which an image is formed (Fig. 2b) corresponding to the indicated voltage. By visually analyzing this voltage, one can evaluate the main parameters of the detected PSK signal.

= N - о количестве N элементарных посылок, по закону чередования коротких разнополярных импульсов - о законе фазовой манипуляции обнаруженного ФМн сигнала.Moreover, the magnitude of the horizontal scan is judged on the duration T of _the signal, on the smallest time interval between short bipolar pulses - on the duration τ _{n of} elementary parcels, in relation

= N - about the number N of elementary premises; according to the law of alternating short, unipolar pulses - about the law of phase manipulation of the detected PSK signal.

Thus, the panoramic receiver in comparison with the prototype provides the detection and visual assessment of not only the carrier frequency ω _c QPSK signal, but also its duration Tc, multiplicity m phase manipulation (magnitude of phase jumps Δφ), the law of phase manipulation, duration τ _n and number N elementary premises.

 Thus, the functionality of the panoramic receiver is expanded.

Claims (1)

 A PANORAMIC RECEIVER containing a receiving antenna in series, a mixer, the second input of which is connected through a local oscillator to the first output of the first sweep generator, an intermediate frequency amplifier, an eight frequency multiplier, a second spectral width meter, a first comparison unit, the second input of which through the first spectrum width meter connected to the output of the intermediate frequency amplifier, the first threshold block, a key, the second input of which is connected to the output of the intermediate frequency amplifier, a delay line, alternately a resident, the second input of which is connected to the key output, and n processing channels, each of which consists of a series-connected bandpass filter, an amplitude detector, a video amplifier and a vertical electrode of a cathode ray tube, the horizontal electrode of which is connected to the second output of the first scan generator, characterized in that, in order to expand the functionality by visual assessment of the main parameters of the detected phase-manipulated signal, a frequency multiplier by four , a frequency multiplier by two, third and fourth measuring instruments for the width of the spectrum, second and third comparison blocks, second and third threshold blocks, three analog converters - code, indicator, (n + 1) -th amplitude detector, frequency detector, second scan generator and (n + 1) -th cathode ray tube, and the first analogue converter, a code and an indicator, are connected in series to the output of the first threshold block, a frequency multiplier for four, and a third spectral width meter are connected in series to the output of the intermediate frequency amplifier RA, the second comparison unit, the second input of which is connected to the output of the first spectral width meter, the second threshold block and the second analog-to-converter converter, the code whose output is connected to the second indicator input, the frequency multiplier by two, the fourth width meter is connected in series to the output of the intermediate frequency amplifier spectrum, the third comparison unit, the second input of which is connected to the output of the first spectral width meter, the third threshold unit and the third analog converter - a code whose output is connected to the third input By the indicator indicator, the (n + 1) th amplitude detector, the second scan generator and the horizontal electrode of the (n + 1) th cathode ray tube, the vertical electrode of which is connected to the key output through the frequency detector, are connected in series to the key output.

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