SU1356229A1 - Device for searching noise-like signal - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to reduce the signal search time. The device includes a mixer 1, a broadband amplifier 2, a demodulator 3, a narrowband amplifier 4, a detector 5 with a low-pass filter, controlled by a local oscillator (L with SP O5

Description

6, discriminator 7, correction amplifier 8, controlled clock generator 9, pseudo-random sequence generators 10 (PSP), switch gates 11, al OR 12 correlators 13, threshold gates 14, threshold el 15, drivers 16 time intervals , keys 17, prohibition units 18, a phasing unit 19, and a multichannel scanning unit 20. After setting the value of the initial delay of clock pulses RD of each generator 10, the search area of the noise-like signal is divided into m sections by N / m cells (where N is the length of the bandwidth, m is the number of correlators 13). one search channel. If during the analysis of the cell does not exceed

13/71, threshold valves 14 |. m threshold elements 15, m formers 16, y | time intervals, m keys 17, m blocks of the prohibition TV, block 19 of the phasing, multichannel scanning unit 20.

The device search noise-like signal works as follows.

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The invention relates to radio engineering and can be used to search for complex noise-like radar signals in telemetry and communications systems.

The aim of the invention is to narrow the search time of a signal. I

The drawing shows a structural electrical circuit of a noise-like signal searching device.

The search device for the noise-like signal contains a mixer 1, a wideband amplifier 2, a demodulator 3, a narrowband amplifier 4, a detector with a low-pass filter (LPF), a controlled local oscillator 6, a discriminator 7, a correction amplifier 8, a controlled clock generator (UTG ) 9, m generators 10 pseudo-random sequence (PSP) (where ha 1,2, ...), m switch gates 11, element OR 12, m correl

low noporojsoro level in the corresponding channel, then in node 20 calculate the number of the investigated cells of the signal uncertainty area for each of the m sections. If during the time of analysis, a low threshold level is observed without exceeding a high one, the analysis time of this cell is increased to the value necessary for a more reliable decision on the presence or absence of a signal in this channel. If during the test time the high threshold level in the channel under test is not exceeded, this channel proceeds to the analysis of the next cell. At the same time, the search in the remaining channels does not stop, which reduces the average search time. 1 il.

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The multichannel scanning unit 20 forms a pulse of the initial setup, which is fed to the SRP generators and the phasing unit 19. Block 19 generates potentials that control the initial delay of clock pulses (TI) J received from the controlled clock generator 9 through blocks 18, prohibiting the SRP generators 10. The initial delay time TI for each generator of the SRP 10 is equal to nN / m, where N is the length of the SRP; m is the number of correlators; n is the number of the correlator of the torus. After counting each N / m clock pulses at the outputs of the phasing unit 19, a constant voltage is recorded allowing TI to pass through the prohibition block 18 to the corresponding generator of the SRP 10. Thus, due to the initial shift of the generators, the SRP 10 it is broken down into m sections by N / m cells, and the search at each site is sensed by one search channel.

The input noise-like signal by mixer 1 is transferred to the intermediate frequency and through the broadband amplifier 2 is fed to the signal

the inputs of the correlators 13, in which the convolution of the input signal and the reference signals from the PSP generators 10 occur. The circuit connected to the outputs of the correlators 13 has two threshold levels: low, above which the convolution voltage in one of the correlators 13 is working - Only that threshold element that is connected to this correlator 13j is high, and when it is exceeded, the corresponding switch valve 11 opens, and the threshold valve 14 closes.

The multichannel scanning unit 20 at intervals equal to the analysis time of one cell of the signal uncertainty region Tjj, commands the end of the cell analysis as an impulse to the inputs of threshold gates 14, if during a time some cell does not exceed the low threshold level in the corresponding . channel, the pulse of the end of the analysis passes in this channel through the threshold valve 14 and

key 17, disarms integrator

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one TI through the block 18p, prohibition on the corresponding generator PSP 10fv | (the reference DSP in this channel is shifted by one clock cycle) and returns to the input of the multichannel scanning node 20 corresponding to this channel, in which the number of cells of the signal uncertainty area for each of the m sections is counted.

The transfer pulse of the multichannel scanning node 20 is also used for the initial installation of the SRP 10 generators and the phasing unit 19 when proceeding to the analysis of the signal uncertainty region of the delay at the next frequency position.

If during the analysis in one of the correlators there is an increase in the low threshold level without exceeding the high one, then the corresponding threshold element 15 connected to this corrector 13 is triggered and the corresponding driver 16 time intervals closes the key 17 connected to it ,, at the time of rechecking a suspicious situation. The analysis time of this cell is increased to the value required for a more reliable

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in kor13 and prohibits the passage

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decide on the presence or absence of a signal in this channel K-T. This is due to the fact that the corresponding key 17 during the test is closed and in this channel the pulse of the end of the analysis of the cell does not pass through it for a time

To-TaEsli during the check did not happen

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If a high level is exceeded in the checked channel, then key 17 opens and passes the pulse of the end of the analysis, and this

Channel 5 proceeds to the analysis of the next cell.

At the same time, unlike the known device, the search in the other channels does not stop, which leads to a reduction in the average search.

If a high threshold level is exceeded in the channel being scanned, the search device decides whether to detect a signal, i.e. the corresponding switch valve 11 is opened and the reference bandwidth of this channel through the EARS element 12 enters the discriminator 7, and the corresponding threshold valve 14 is closed, disabling the search, and the device goes into signal tracking mode. This mode is implemented by an automatic frequency control circuit, which includes mixer 1, wideband amplifier 2, demodulator 3, narrowband amplifier 4, detector 5, controlled local oscillator 6, and a delay tracking circuit that includes the PSP 10 generator of the detected channel corresponding to

switch valve 11 ,, element OR 12, discriminator 7, correction amplifier 8, controlled clock generator 9 and the corresponding prohibition block 18. Block 18 of the prohibition can be made in the form of a trigger triggered by the pulse of the end of the analysis for the time of passage of one TI, and the output of the trigger is combined on the circuit of the AND element with two other inputs of the block 18 of the prohibition. In the tracking mode, these inputs of the prohibition unit 18 are supplied with constant voltages that allow the TI to pass through it to the SRP generator 10 included in the tracking circuit.

Formula of invention

Device search noise-like signal (PSS), containing a sequence

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The mixer is the one whose data input is the information input of the PSH search device, a microband amplifier, a demodulator, a narrowband amplifier, a low-pass filter (LPF) detector and a controlled local oscillator, the output of which is connected to the second mixer input, serially connected element OR, to the inputs of which are connected the outputs m of switch valves (where m 1j2 ,, ..,) is a discriminator, to the second input of which are connected the signal outputs m of correlators and the output of a broadband amplifier, a correction device An actuator and a controlled clock generator (UTG), m thresholds VONtils, to the signal inputs of which the corresponding inputs are connected to the threshold elements, m switch gates and outputs of the corresponding m correlators, and also a pseudo-random sequence generator (PSP) 5 whose output is connected to the reference input signal t - th correlator and signal input of the t-th switch valve, and series-connected shaper time intervals, the information input of which is connected to the output of the first threshold el 5 and the output is connected to the input of the signal Reset the first correlator and the first input of the multichannel scanning node, the first output of which is connected to the control: local, by its input of the controlled local oscillator, this to the second input of the demodulator is connected to the output element

Editor L.Povkhan

Compiled by h. 1 racianska

Tehred L, Serdyukov Proofreader A.Zimokosov

Order 5813/55 Circulation 636. Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-355, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

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that Ya.PI, about tl and h iu e s with the fact that, from the time of the signal search time, introduced t-1 pseudo-case generator of the 1st consecutive: tnogti (PSP), the outputs of which are so1; inen with signal inputs i and corresponding t-1 switch valves and inputs of the reference, t-1 correlators, t-1 timers, to the information inputs of which the outputs of the corresponding threshold elements are connected, TP-1 keys, to the control inputs of which the outputs are connected corresponding timers, to the signal inputs - The outputs of the corresponding threshold ventilators are connected, and the outputs of t-1 keys are connected to the input of the signal. Resetting the corresponding t-1 correlators and (t- |) inputs of the multichannel scanning node 5 as well as m prohibition blocks and a phasing unit The outputs of which are connected to the first inputs of each of the m prohibition blocks, to the second inputs of which the outputs of the corresponding m keys are connected, and VEYAKHODES are connected to the TOBbiMJi inputs of the corresponding SRP generators, to the inputs of the initial installation of which the initial input is connected SETTING phasing unit and a second output node multichannel scanning, the third output is connected to second inputs of m threshold valves and to the clock input node multichannel scanning unit and the phasing of each block is the output connected prohibition controlled oscillator.

Claims (1)

Claim A noise-like signal (SPS) search device containing a sequence of 1 <2 6 2 2 9 a specially connected mixer, the normal input of which is the information input of an ALS search device, a broadband amplifier, a demodulator, a narrow-band amplifier, a low-pass filter (LPF) detector and a controlled local oscillator, the output of which is connected to the second input of the mixer, in series connected element ₁₀ OR, to the inputs of which the outputs of m switch gates are connected (where w = 1,2, ...,) _; discriminator, to the second input of which is connected to the signal outputs of the correlators and m You are a broadband amplifier ₁₅ stroke, the correction amplifier and a controllable clock oscillator (UTG), m threshold valves, to signal inputs of which are connected respective rows of vho- ₂ m threshold elements, m commutator gates and outputs of the corresponding correlators m, and the pseudorandom sequence generator (SRP), whose output is linked to the ₂ 5 inputs the reference signal fr and the second correlator signal input m-th commutator venti A, and serially connected generator slots, to an information input of which is connected to the output of the first threshold element, and the key to the signal input of which is connected to the output of the first threshold valve, and the output - connected to the input signal. Reset ”of the first correlator and the first ³⁵ input of the multi-channel scanning unit, the first output of which is connected to the control input of the controlled local oscillator, while the output of the OR element is connected to the second input of the demodulator, which means that, to reduce the search time of the signal, t-1 pseudo-random sequence generators (PSS) have been introduced, the outputs of which are connected to the signal inputs of the corresponding t-1 switch gates and the inputs of the reference signal, t-1 correlators, m-Ι time interval shapers, to the information inputs of which the outputs of the corresponding threshold elements are connected, t-1 keys, the outputs of the corresponding shaper of time intervals are connected to the control inputs of the outputs, the outputs of the corresponding threshold valves are connected to the signal inputs, and the outputs of each of the t-1 keys are connected to the inputs of the Reset corresponding t -1 correlators and (t-1) -th inputs of a multi-channel scanning unit, as well as m block prohibitions and a phasing block, the outputs of which are connected to the first inputs of each of m blocks beyond a proton, to the second inputs of which the outputs of the corresponding m keys are connected, and the outputs are connected to the clock inputs of the corresponding SRP generators, to the inputs of the initial installation of which are connected the input of the initial installation of the phasing unit and the second output of the multi-channel scanning unit, the third output of which is connected to the second inputs of m threshold gates, and the output of a controlled clock is connected to the clock input of a multi-channel scanning unit, a phasing unit, and each of the m prohibition blocks ”