SU1651225A1 - Device for detecting periodic pulse sequences and evaluation of their periods - Google Patents

Abstract

The invention relates to a pulse technique and can be used in devices for detecting and estimating the parameters of periodic pulse signals in radio astronomy, radiophysics, and radiolocation. The aim of the invention is to increase the resolution of the detection of the temporal position of periodic pulse sequences in the presence of additive noise and impulse noise. For this, a modular converter 5, a decoder 7, counters 8.1 ... 8.P, a multiplexer 9, a threshold setting unit 11, a deduction key 12, a module key 13, a module specification unit 14, an analysis strobe driver 15, output bus 18 are entered into the device. residue, output bus 19 module. In addition, the device contains an input bus 1, a quantizer 2, a gating unit 3, a pulse shaper 4, a pulse register 6, a threshold device 10, a 16 clock pulse generator, and an output bus 17 for detection. 3 il. W b ate gs go ate fig

Description

The invention relates to a pulse technique and can be used in devices for detecting and evaluating parameters of periodic pulse signals in the presence of additive noise and pulse interference, for example, in radio astronomy, radio physics, and radar.

The purpose of the invention is to increase the detection resolution of the temporal position (initial phase) of periodic successive pulses in the presence of additive noise and impulse noise.

Fig. 1 shows a functional diagram of a device for detecting periodic pulse sequences and evaluating their period; Fig. 2 shows a functional diagram of a modular converter i in Fig. 3 — time diagrams explaining the principle of operation of the device.

The device (Fig. 1) contains an input bus 1, a quantizer 2, a gating unit 3, a pulse shaper 4, a modular converter 5, a memory register 6, a decoder 7, counters 8.1 ... 8.P, multiplexer 9, threshold unit 10, block 11 threshold settings, deduction key 12, module 13 key, module definition module 14, analysis gateway generator 15, clock generator 16, detection output bus 17, residue output bus 18, module output bus 19, threshold voltage input bus 20.

The input bus 1 is connected to the first input of the quantizer 2, the second input of which is connected to the input bus 20 of the threshold voltage, the output of the quantizer 2 is connected to the first input of the gating unit 3, the output of which is connected to the input of the pulse former 4, the output of which is connected to the first input of the modular converter 5, the second input of the memory register 6 and the first inputs of counters 8.1 ... 8.P, the outputs of which are connected to the corresponding inputs of the multiplexer 9, (n + 1) -th input of which is connected to the input of the decoder 7, the first input of the key 12 and the output m register memory 6, a first input coupled to an output transducer unit 5, a second input coupled to an output of the setting unit 14 and the first input switch module 13, the second input of which

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connected to the second input of the deduction key 12, the detection output bus 17 and the output of the threshold unit 10, the first input of which is connected to the output of the multiplexer 9, the second input of the threshold unit 10 is connected to the output of the threshold setting unit 11, the third input of the modular converter 5 is connected to the second input of the unit 3 gates, the third inputs of counters 8.1 ... 8.P and the output of the imaging unit 15 of the analysis gate, the input of which is connected to the fourth input of the modular converter 5 and the generator output 16 clock pulses, the outputs of the decoder 7 are connected to the second inputs of the corresponding counters 8.1 ... 8.P, the output of the deduction key 12 is the output bus 18 of the deductions, the output of the key 13 of the module is the output bus 19 of the module.

The modular converter 5 (Fig. 2) contains a binary counter 21, a block 22 for comparing codes, a block 23 for resetting, a key 24 for removing residues.

The first input of the modular converter is connected to the first input of the switch 24, the second input of which is connected to the output of the counter 21 and the first input of the code comparison unit 22, the second input of which is connected to the second input bus of the modular converter, the third input bus is connected to the second input of the counter 21 , the third input of which is connected to the output of the reset unit 23, the input of which is connected to the output of the code comparison unit 22, the first input of the counter 21 is connected to the fourth input bus of the modular converter, the output bus of which an output switch 24. The principle of operation of the device detecting the periodic pulse sequences, and evaluation of their selective properties period laid modular converting time slots tj, whereby these slots are formed residues modulo a trial period t;

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The value of t. represents, the time interval between the beginning of the analysis interval Tv and the moment of occurrence of the 1st pulse in the analyzed sequence, i.e.

t is the remainder of dividing t j

on tj.

The temporal position of the signal periodic sequences with the period Tt, Tg (Fig. 3a, b) is determined by the instant of the first pulse

t sequences

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The chaotic impulse noise is shown in FIG. 3. The additive mixture of IP “Up, UQ- and Uj, is represented by the time diagram U“. (fig.Zd).

The algorithm of the device can be represented as follows.

The pulse sequence (a mixture of signal and interfering components), hfg. H, normalized in amplitude and duration, characterized by moments of the appearance of pulses and specified in the interval T0, undergoes a modular transformation (1).

In the resulting set of residues &t; i (Fig. Ze), the number Ni ({};) of the same residue values is calculated.

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The value of NlCc1.) Is compared with the threshold value N

) ° N (Cj) Ј.

In the case of Ni (Ј-.) 5: N: Q, the detection of a periodic pulse sequence is recorded, to which the values of the period T T are attributed: and the temporary position (initial phase)

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The device works as follows.

The input signal (FIG. 13) from the input bus 1 is fed to the first input of the quantizer 2, where it is subjected to binary quantization by comparing i1 with the threshold voltage applied to the second input of the quantizer from the input bus 20. This performs pulse amplitude detection and normalization of the signal amplitude . From the output of the quantizer 2, the amplitude-quantized signal arrives at the first input of the gating unit 3, which passes a signal through itself for a certain interval T, called the analysis gate, which is generated by the analysis gateway generator 15 and simultaneously also fed to the third input of the modular converter 5 and connected between third inputs of counters 8.1 ... 8.P,

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allowing them to work within the Tc interval. Outside this interval, the voltage from the output of the analysis gate generator 15 maintains the locked state of the gating unit 3, sets to zero and holds the modular converter 5 and counters 8.1 ... 8.p. The gated signal from the output of gating unit 3 is fed to the input of the pulse shaper 4, which performs the function of normalizing the signal in terms of duration. The output signal from the pulse shaper 4, which is a sequence of pulses normalized in amplitude and duration, is fed to the first input of the modular converter 5, as well as to the second input of memory register 6 and the first inputs of counters 8.1 connected to it. ... 8.p. In modular converter 5, the formation of residues is performed.

5 points of pulse occurrence, counted from the beginning of the sequence (beginning of the analysis strobe), modulo the trial period (in accordance with (1) arriving at the second input

0 of the modular converter 5, and the first input of the key 13 of the module from the output of the block 14 of the task of the module.

The deduction of the moment of occurrence of each pulse of the sequence from the output of the modular converter 5 is fed to the first input of memory register 6, where it is fixed by the pulse itself coming to the second input and transmitted from the output to the first input of key 12, (n + 1) -th multiplexer input 9 and the input of the decoder 7, at one of the outputs of which 1, 2, ..., n the level of the logical unit is formed,. which increases the content of the corresponding counter 8.1 ... 8.P

(fig. 3, 3, 3) by the pulse itself, which is sent to the first inputs of counters 8.1 ... 8.P, which are connected to each other, and which is a clock for these counters. In order to temporarily reconcile the operation of modular converter 5, register 6 of memory and counters 8.1 ... ... 8.n, the operation of modular converter 5 begins on the front of the input pulse, and its effect on register 6 of memory and counters 8.1 ... 8. P is implemented with a small delay, taking into account the final speed of the blocks. This delay can be up to 5

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crucified by the action of register 6 of memory and counters 8.1 ... 8.P on a shear of a pulse or on a leading edge, but with a corresponding delay introduced into blocks 6 and 8.1 ... .8, p. Thus, counters 8.1 ... 8.P accumulate a number of units equal to the number of identical residues formed during the TQ analysis interval by the modular converter 5, with each counter counting the number of well-defined identical residues. In the simplest case, the counter 8.1 counts the number of deductions equal to 1 counter 8.2 - the number of deductions equal to 2, etc., the counter 8.n - the number of deductions equal to n. The number of identical deductions from the outputs of the counters 8.1 ....,. 8 P is fed to the corresponding inputs 1, 2, ..., p of a multiplexer 9 controlled by the control input (n-H) with the same deduction value that is fed to the input of the decoder 7. Therefore, when one of the counters 8.1 ... 8.The next unit is added, the output of the same counter by multiplexer 9 is connected to its output and further to the first input of the threshold unit 10, in which the number of residues in the counter is compared with the threshold number of detection of a periodic sequence given to the second input of the threshold block from the output of the threshold setting block 11.

Thus, when each pulse of the sequence arrives at the device input within the strobe of the analysis T0 after forming the corresponding deduction and adding the unit to the contents of the corresponding counter 8.1 ... 8.P, the number recorded in this counter is compared with the detection threshold. If the number of residues arriving at the first input of the threshold unit 10 is equal to or exceeding the detection threshold number at its second input, then the output of the threshold unit is formed the level of the logical unit, which, acting on the second inputs of the keys 12 and 13, unlocks them and the value of the residue, characterizing the time “- the position of the detected sequence from the input of the key 12 is transmitted to, its output and the output bus 18, and the value of the conversion module T-, equal to the period detected

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A periodic periodic pulse sequence acting at the input of the key 13 is transmitted to its output and the output bus 19 of the module.

Upon completion of the analysis strobe (outside the analysis interval T,) the gating unit is locked, the modular converter 5 and the counter 8.1 ... 8.P are reset. The device is ready to perform the analysis of the next implementation of the pulse sequence T.

It should also be noted that the DT, T0 and the period of the clock pulses T9 of the generator 16 are interconnected, as the relationship must be fulfilled. Providing the potential resolution over the period of the DTT UTj:

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providing time discretization of the pulse occurrence moments in the stream with modular conversion in block 5 with an accuracy of a discrete value equal to T, which ensures the formation of identical values of residues t from the instants t "of the appearance of periodic component pulses with equal Tc and T: with accuracy to discrete DT :.

The principle of operation of the modular converter 5 is as follows. The first input of the binary counter 21 is supplied with a continuous sequence of pulses, which are counted only within the analysis strobe applied to the second input of the binary counter, which also serves to keep the binary counter in the zero state outside the analysis strobe. When counting pulses at the output of a binary counter, an increasing binary number is formed, which is fed to the second input of the residue extraction key 24 and the first input of the code comparison unit 22, to the second input of which the binary code of the trial period T is fed. At the moment when the binary code is the first input of the code comparison unit 22 is compared with the deduction code T acting on

its second input, at the output of the code comparison unit, a voltage drop is generated, which, through the reset unit 23, affecting the third input of the binary counter 21 (the zero setting input), resets its contents to zero. Next, the counting cycle is repeated. Thus, the binary counter 21, when combined with the code comparison unit 22 and the reset unit 23, has a conversion factor of T: i.e. counts the number of reference intervals of the pulse sequence at the first input of the binary counter 21 modulo T :. In other words, at the output of binary counter 21 within the analysis strobe, starting from its beginning to its end, the binary code of the current time, measured modulo T:, is generated. Therefore, the signal pulses of the analyzed sequence, arriving at the first input of the residue removal key 24, open it, and at its output a deduction code is generated, which is valid at that time at the second input of the residue removal key.

Claims (1)

Invention Formula A device for detecting periodic pulse sequences and estimating their period, containing a quantizer, gating unit, pulse shaper, memory register, threshold unit, clock generator, output, detection bus connected to the output of the threshold unit, the first input of the quantizer connected to the first input bar device, the second input bus of which is connected to the second input of the quantizer, the output of which is connected to the first input of the gating unit, the output of which is connected to the input 0 five 0 five 0 five 0 five pulse shaper house, characterized in that, in order to increase detection resolution in temporal position, a modular converter, a decoder, n counters, a multiplexer, a threshold setting unit, a deduction key, a modulus key, a module specifying unit, an analysis strobe generator, are introduced into it a clock pulse, while the output of the pulse former is connected to the first input of the modular converter, the second input of the memory register and the first inputs n of the counters, the outputs of which are connected to the corresponding the multiplexer inputs, (n + 1) -th input of which is connected to the first input of the deduction key, the input of the decoder, the output of the memory register, the first input of which is connected to the output of the modular converter, the second input of which is connected to the output of the module of the module and the first input of the key the module, the second input of which is connected to the second input of the deduction key and the output of the threshold unit, the first input of which is connected to the multiplexer output, the second input of the threshold unit is connected to the output of the threshold setting unit, the third input of the modular converter connected to the second input of the gating unit, the third input of each of the n counters and the output of the analysis gateway generator, the input of which is connected to the fourth input of the modular converter and the output of the clock pulse generator, the decoder outputs are connected to the second inputs of the corresponding (counters, output of the deduction key) The output bus is the residue, the output of the module key is the output bus of the module. t "IIc JLilL - eG Jte 7s 77 g t ± J L L-JLL t-ltil ljj -.-. V4 s tgtj ° // 1: G 10 9 T four, and Phie, 2 ± 3, B: L i i t Jll m Ґ I