SU1334378A1 - Device for searching noise-like signals - Google Patents

Abstract

Invention m. used in broadband radio communication systems. The purpose of the invention is to reduce the search time for noise-like signals, depending on the power of the interfering noise. The device contains demodulator 1, narrowband amplifier 2, detector op 3 with filter, discriminator 4, correction amplifier 5, controlled clock generator 6, element OR 7, driver 8 time slots, switches 9 and 10, and n channels of detection 11, - 11. Each detection channel consists of a mixer 12, a wideband amplifier 13, a correlator of a torus 14, a threshold unit 15, a scanner to frequency 16, a pseudo-random sequence generator 17, (n + 2) -shift shift registers 18 the local oscillator 19, the inverter 20 and the gates 21-24 . 1 3.p. f-ly, 1 ill. (Oh, 4:00 vj 00

Description

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 1334378

The invention relates to a radio pulse technique and can be used in wideband radio communication systems.

The aim of the invention is to reduce the search time for noise-like signals, depending on the power of the interfering noise.

The drawing shows a structural electrical circuit of the device for searching noise-like signals.

The device for searching noise-like signals contains demodulator 1, narrow-band amplifier 2, detector 3

with filter, discriminator A, corrections-15 in their first bits were recorded a booster amplifier 5, controlled by a switch, and in all others - a generator 6, an element OR 7, a for- est control signal intervals, the first bit () is the first 9 and second 10 switches and a shift register 18 allows passage 11 - 11 "detections, connecting from the inputs to the output of the switch

The pulses coming from the output of the second valve 22 are counted from in block 16 of scanning by frequencies and every time after viewing the entire uncertainty area of delay, it issues a command to rebuild the controlled local oscillator 19 s

t; -, where Tj is the integration time

J in the Correlle Torus 19 on the J-M stage of the search

(n + 2) -display registers 18 shift in the absence of synchronism are in the initial state in which

units, and in all others - zeros.

each of which includes a mixer 12, a wideband amplifier 13, a correlator 14, a threshold unit 15, a frequency scanning unit 16, a pseudo-random sequence generator 17, (n + 2) -discharge shift register 18, a controlled local oscillator 19, an inverter 20, the first - a quarter of the valves 21-24.

The device works as follows.

The input of the mixer 12 of each detection channel, and then via the broadband amplifier 13, to the correlator 14, receives a received noise signal with unknown delay and frequency. The task of the search device is to determine these parameters with an accuracy determined by the signal uncertainty function. For this, in each detection channel, a pseudo-random sequence generator 17 is supplied with a copy of the signal to the correlator 14, tuned sequentially in time with step t

;. Such a rearrangement with the absence of S-r HII synchronization is carried out, one

once during the integration of the result of processing the received signal in the correlator 14, since in this case there is no voltage at the output of the threshold unit 15 and the pulses fed to the input of the second valve 22 from the output of the switch 25 with a duration equal to the period of the clock pulses T controlled the clock generator 6, prohibit the passage through the third valve 23 of a single clock

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in their first bits are written, and in all others, the control signal from the output of the first bit () -discharge shift register 18 permits the passage from the inputs to the switch output

The pulses coming from the output of the second valve 22 are counted in the frequency scanning block 16 and every time after viewing the entire uncertainty area, it issues a command to rebuild the controlled local oscillator 19 s

t; -, where Tj is the integration time

J in the Correlle Torus 19 on the J-M stage of the search,

(n + 2) -display shift registers 18, in the absence of synchronism, are in the initial states at which

units, and in all others - zeros.

25 of only that signal which is fed from the imager of 8 time slots to the input of the detection channel. Since the output of the threshold unit 15 at

If there is no synchronism, the level is low, then at the output of the inverter 20 it is converted to high and the first valve 21 is in the open state. Impulses coming from the entrance

the switch 25 through the first gate 21 to the fault input of the (n + 2) -discharge shift register 18, reliably holds the latter in the initial state. Thus, since the input of each detection channel receives signals from various outputs of the imager, there are 8 time slots; then each of the detection channels scans a region of frequency uncertainty

and delay with its speed.

If in any detection channel the voltage at the output of the correlator 14 exceeds the threshold of the threshold unit 15, then the output of the inverter 20 will be low level which will prohibit the supply of the (n + 2) -discharge shift register 18 through the first gate 21 pulses reset to the initial state, and the level of the unit that was in the first discharge of the (n + 2) -shift register 18 of the shift, will go to its second discharge thanks to the voltage drop from the threshold block 15, which is higher on its counting input The output voltage of the threshold unit 15 will now be prohibits the passage of the pulses through a second valve 22 on. the third valve 23 and the frequency scanning block 16, and

therefore, the delay and frequency scanning will stop. At the output of switch 25, now only the signal coming from the driver of 8 time intervals to the input of the detection channel will now pass, since the level of the unit will now be only on that control input of switch 25, which is connected to the output of the second bit (n + 2) -discharge register 18 shift. Thus, the integration time of the processing result in the correlator 14 is increased. In the threshold unit 15, a threshold is established corresponding to the optimal parameters of the second stage of the search for a given detection channel. If now the threshold in threshold block 15 is not exceeded, then the first valve 21 at the moment of passing the waste pulse for the (n + 2) -discharge shift register 18 will be open and the detection channel, returning to the initial state (at the first search step) will continue the search. If by the time of the next integration again

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the threshold will be exceeded in poro1. A search device for noise-like 2Q signals containing successively double-checking a connected demodulator, a narrowband amplifier and a low-pass filter detector, a discriminator connected in series, a correction amplifier and a controlled clock generator, as well as combined by the signal input of the detection channels, the outputs of which are through the element OR are connected to the first combined inputs of the demodulator and the discriminator, characterized in that, in order to reduce the search time for noise-like signals depending power exerted by the interference introduced shaper timeslots.

If the unit already turns out to be in the third bit of the (n + 2) -discharge shift register 18, and the decision about the presence of the signal will be made with a TZ integration time longer than T1 and T2. The last recheck of the decision on the presence of a signal is made when the unit is in the last bit (n + 2) - bit shift register 18. If the search device has p-step detection channels and the nth channel with maximum noise immunity is three-step, then for any detection channel the integration time in this case will be equal to 40

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nym. The level at the output of the last bit (n + 2) -shift register 18 of the shift opens the fourth gate 24, the pseudo-random sequence from the output of the generator 17 of the pseudo-random sequence through the quarter-turn gate 24 and the element OR 7 enters the information receiving channel and to the inputs of the discriminator 4 and demodulator 1, the level of the last 45

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the first and second switches, while the output of the controlled clock generator is connected to the input of the time interval generator and to the input of each of the n detection channels, the outputs of the time interval former are connected to the corresponding n + 2 control inputs of each of the detection plexes, the first additional exit of each through

its bit (n + 2) -bit register — the first switch is connected to the input of the 18 shift and will go to the corresponding reference signal of the first 9 and second 10 switches corresponding to this detection channel.

detection, and through the second switch - to the combined second

The second switch 10 connects the output of the wideband amplifier 13 of this detection channel to the second inputs of the discriminator 4 and demodulator 1, and the first switch 9 to the output of the detector 3 with a low-pass filter to the controlled local oscillator 19 of the same detection channel. Thus, discriminator 4 and demodulator 1 will start working on the detection channel, which is in sync with the received signal.

(n + 2) -discharge shift register 18 is implemented so that the output of the (n + 1) -th bit is connected to the input of the (n + 2) -th bit via the element OR 7, the second input of which is connected to the output (n 2) th bit.

Thus, after entering into the synchronism of any channel, the detection of erasure of level 1 from incoming clock pulses in its (n + 2) - bit shift register 18 does not occur,

Formula of invention

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2Q

2Q

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Claims (2)

1. A search device for noise-like Q signals containing a demodulator connected in series, a narrowband amplifier and a low-pass filter detector, a discriminator connected in series, a correction amplifier and a controlled clock oscillator, as well as combined by the signal input of the n detection channels whose outputs through the element OR are connected to the first combined inputs of the demodulator and the discriminator, characterized in that, in order to reduce the search time for noise-like signals depending on the power and actuating interference introduced shaper timeslots. five 0 the first and second switches, while the output of the controlled clock generator is connected to the input of the time interval generator and to the input of each of the n detection channels, the outputs of the time interval former are connected to the corresponding n + 2 control inputs of each of the detection plexes, the first additional exit of each through  the first switch is connected to the input of the reference signal of the corresponding the first switch is connected to the input of the reference signal corresponding to detection, and through the second switch - to the combined second 51 to the inputs of the discriminator and demodulator, the second additional outputs of the n detection channels are connected to the corresponding inputs of the second switch, the output of the detector with a low-pass filter is connected to the corresponding input of the first switch. 2. The device according to claim 1, characterized by the Thames, that the cluster of p detection channels is made in the form of a series-connected frequency scanning unit, controlled by a retterine, a mixer, a wide-band amplifier, a correlator, to another input of which a pseudo-random sequence generator is connected ( PSP), threshold unit and (n + 2) -discharge shift register, the outputs of which bits through the switch are connected to control inputs of the first and second valves and to the corresponding input of the correlator, the output of the threshold unit connected via serially connected 0 the inverter and the first valve to the corresponding input of the (n + 2) -discharge shift register and through the second valve to the input of the frequency scanning unit and to the input of the third valve, the output of which is connected to the input of the SRP generator, which is connected to one of the inputs of the fourth valve, To the other input of which the output of the (n + 2) -th bit, (n + 2) -sized shift register is connected, the control input of the third valve, the other input of the mixer, another input of the local oscillator and (n + 2) the control inputs switches are respectively input, signal input ohm, the reference signal input and control inputs for the: each detection channel, and the fourth gate output, the output of the (n - 2) -th bit (n-1-2) -discharge shift register and the output of the wideband amplifier are respectively, the output and the first and second additional outputs of each detection channel. five 0