RU2319201C1 - Multi-channel polar correlator - Google Patents

Abstract

FIELD: engineering of specialized devices, meant for determining correlation functions of random processes.

SUBSTANCE: correlator consists of circular distributor (1), containing generator of clock impulses and serially coupled triggers (2), two limiter amplifiers (3), key circuits (4), logical elements "AND" (5,9), "OR" (6) and "NOT" (7), memorizing element (8) and impulse counters (10). In circular distributor (1) between "n" and "1" triggers (2), a "n+1" trigger (2) is additionally coupled, which makes it possible to introduce additional preparation operation for memorizing element (8), in other words, its nullification. Second input of "n+1" trigger (2) by preparation signal is connected to output of "n"-trigger (2), and its first output is connected to controlling input of additional "n+1" key circuit (4), input of which is connected to output of memorizing element (8), and output - to ground connection. Input clamp by second input signal through second limiter amplifier (3) is connected to second input contact of mode switch (12), its first input contact is connected to input of first key circuit (4) and to output of first limiter amplifier (3), input of which is connected to input clamp of first input signal; output contact of mode switch (12) is connected to second input of "AND" element (9).

EFFECT: increased precision of multi-channel polar correlator, expanded functional capabilities of correlator due to introduction of mode for determining mutual correlation function of two signals.

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Description

The invention relates to specialized computing devices for determining the correlation functions of random processes.

A wide class of correlators is described in [1], but most of them are complex in technical and circuit implementations.

The analogue is the multi-channel polar correlator according to copyright certificate No. 327495 [2], consisting of a ring distributor 1 containing a clock pulse generator 11 and triggers 2, auxiliary triggers 3 and 4, key circuits of the first group 5 ₁ -5 _n , key circuits of the second group 5 ₁ -5 _m , diodes 6 and 7, amplifier-limiter 8, logic element 9 and pulse counters 10. However, this multichannel correlator does not have high accuracy, since it takes into account the number of pulses in the absence of the signal under study at τ = 0.

The prototype is a multi-channel polar correlator according to copyright certificate No. 2210105 [3], consisting of an annular distributor 1 containing a clock generator 11 and triggers 2 ₁ -2 _n , an amplifier-limiter 3, key circuits 4 ₁ -4 _n , the first 5 and second 9 logical elements “AND”, logical element “OR” 6, element “NOT” 7, memory element 8 and pulse counters 10 ₁ -10 _n .

However, as experimental studies have shown, this correlator also has some disadvantages:

- in the study of a random signal with a wide high-frequency spectrum of frequencies, the storage element does not provide the removal and storing of the high-frequency signal, which leads to some decrease in its accuracy;

- it is not possible to determine the mutual correlation function of two signals, which is extremely necessary when studying the dynamics of self-propelled guns under random external influences and internal changes in parameters.

The objective of the invention is to improve the accuracy of the multi-channel polar correlator, as well as expanding its functionality by introducing a mode for determining the mutual correlation function of two signals.

Improving the accuracy in the proposed correlator is achieved by introducing an additional operation of preparing the storage element, i.e. its zeroing, which is realized by parallel connection to its output "n + 1" of a key controlled by the output pulse from the "n + 1" trigger, which is additionally included in the ring distributor between the "n" and "1" triggers of the ring distributor. This allows at the end of each cycle of comparative evaluation of discrete values of the random signal under investigation to carry out the zeroing of the storage element, which completely eliminates the possibility of an error due to the value of the stored signal in the previous correlator operation cycle. Thus, the polarity is only memorized for the current signal value, which helps to increase the correlator accuracy and to expand the frequency range of the random signals under investigation. Expanding the functionality of the correlator is achieved by introducing the operation of determining the mutual correlation function of two random signals while maintaining the operation of determining the correlation function of a random signal.

This is achieved by the fact that two modes of operation of the multi-channel polar correlator are introduced:

- first, the determination of the correlation function of a random signal, when both storing and evaluating its cross-section values at discrete time instants is performed for the same random signal under investigation;

- second, when the determination of the mutual correlation function of two random signals, that is, the polarity of the signal is stored for one, and the values of the cross sections at discrete time instants are estimated for the second random signal relative to the stored first.

This is achieved by introducing a second limiting amplifier and a mode selector switch.

The essence of the invention lies in the fact that a multi-channel polar correlator containing an annular distributor consisting of a clock pulse generator and serially connected triggers, the first inputs of which receive pulses from the generator, and the second input of each subsequent trigger is connected to the second output of each previous trigger, n keys , the first amplifier-limiter, the input of which is connected to the first input terminal by the first input signal, and the output - with the input of the first key, the first and second logical “And” copies, memory element, n counters, “OR” and “NOT” logic elements, while the output of the first trigger is connected to the control input of the first key and the first input of the first logical element “AND”, the signal is input from the output of the first key memory element, from which the stored polar signal is fed to the first input of the second logical element "AND", also from the output of the first key, the signal directly goes to the first input of the logical element "OR", and to its second input through the logical element "NOT", with output logic of the OR element, the signal enters the second input of the first AND gate, from the output of which the signal goes to the first pulse counter, from the output of the second AND gate, the signal through the corresponding public key, when the corresponding triggers of the ring distributor are sequentially activated, goes to the corresponding a pulse counter; in this case, an n + 1 trigger is additionally included in the annular distributor between n and the first triggers, the second input of which is connected to the second output n tr by the preparation signal Igger, and its first output is connected to the control input of an additional n + 1 key, the input of which is connected to the output of the storage element, and the output n + 1 of the key is connected to the ground terminal, the second input terminal of the correlator is connected to the second input signal through the second amplifier-limiter the second input contact of the mode switch, and its first input contact is connected to the input of the first key, the output contact of the mode switch is connected to the second input of the second logical element "AND".

The invention is illustrated by the electrical functional diagram of a multi-channel polar correlator, shown in the drawing.

The electrical functional diagram consists of a ring distributor 1, containing a clock generator 11 and triggers 2 ₁ -2 _{n + 1} , the first and second limiting amplifiers 3 ₁ -3 ₂ , key circuits 4 ₁ -4 _{n + 1} , the first and second logical “AND” elements 5 and 9, “OR” logic element 6, “NOT” element 7, memory element 8, pulse counters 10 ₁ -10 _n and mode switch 12.

The multi-channel polar correlator works as follows:

When determining the correlation function of a random signal, that is, in the first mode of operation, the mode switch 12 is set to position 1-3. The studied input signal U _x is fed to the input of the first amplifier-limiter 3 ₁ and the amplified signal is fed to the input of the key 4 ₁ and through the mode switch 12 (pins 1 and 3 are closed) - to the second input of the logic element "I" 9. From the output of the clock generator pulses 11 pulses are supplied to the first inputs of triggers 2 ₁ -2 _{n + 1} , ring distributor 1. When the first trigger 2 _{1 is} triggered from its output, a voltage pulse is supplied to the control input of the key circuit 4 ₁ and the first input of the first logic element "AND" 5.

This opens the key circuit 4 ₁ through which the amplified input signal U _{1 is} fed to the input of the storage element 8. The stored polar signal is then fed to the first input of the second element "And" 9. Moreover, the current input to the second input of the second element "And" 9 the value of the amplified input signal from the output of the amplifier-limiter 3 ₁ through the closed contacts 1-3 of the switch 12. From the output of the second logical element "AND" 9 the signal is taken only at the moment of triggering 2 ₂ -2 _n when the polarity of the current value The input signal U ₁ and the stored and through the public key 4, groups of keys 4 ₂ -4 _{n is} supplied to the corresponding pulse counter 10 ₂ -10 _i -10 _n . The first counter 10 ₁ counts only the correlator duty cycles, that is, if there is a signal at the output of the storage element 8.

This is achieved as follows. The "OR" 6 element is configured for positive operation only if there is an input signal and at any polarity thereof, since the output of the key 4 ₁ , the input signal U ₁ goes directly to the first input of the "OR" 6, and to its second input through the element is NOT. Therefore, in the presence of an input signal U ₁ and when the trigger 2 _{1 is} triggered from the output of the element "OR" 6, a positive signal is supplied to the second input of the first element "And" 5. And since the signal from the first input to the first input of the first element "And" 5 trigger 2 ₁ ring distributor 1 is also positive, then the output of the first element "And" 5 to the first pulse counter 10 ₁ receives a signal only if there is an input signal U _{1 of} any polarity.

Therefore, in the absence of an input signal from the output of the element "And" 5 does not receive a pulse to the counter 10 ₁ , the storage element 8 does not fix the polarity of the input signal and this duty cycle is excluded from the number measured.

If the polarity of the input signal U _{1 is} fixed by the storage element 8, then when the trigger 2 _{2 is} triggered, a signal is removed from its output, which opens the key circuit 4 ₂ . If the polarity of the current value of the input signal U ₁ and the signal from the output of the storage element 8 coincide at the inputs of the second element "And" 9, then from its output through the open key circuit 4 ₂ to the input of the counter 10 ₂ receives a pulse. Similarly, key circuits 4 ₃ -4 _n and counters 10 ₃ -10 _{n are} triggered when the corresponding triggers 2 ₃ -2 _{n of} ring distributor 1 are successively triggered. Then trigger 2 _{n + 1 is} triggered and its output signal opens the key circuit 4 _{n + 1} , which leads to zeroing the output signal of the storage element 8, that is, preparing it for the next storage of the input signal U ₁ .

At the end of one cycle of operation of the ring distributor 1, a pulse appears again in the first trigger 2 ₁ , which leads to the memorization of the new current value of the input signal and in the future the cycle of work is repeated.

To determine the mutual correlation function of two random signals U ₁ and U ₂ , that is, when the correlator is in the second mode, the mode switch 12 is switched to the second position (contacts 2 and 3 are closed) and the second random signal U ₂ under investigation is supplied (connected) to the input second limit amplifier 3 ₂ . The principle of operation of the correlator in this mode corresponds to the above, and at the beginning of each cycle of its operation, the polarity of the input signal U _{1 is} remembered, but a comparative assessment is already carried out with the current values of the input signal U ₂ .

After the time required to determine the sign correlation function has elapsed, counts are taken from the pulse counters and the probability of coincidence of the signs is determined as the ratio of the number recorded in the corresponding counter to the number recorded in the first counter. The normalized correlation function of a random process is found through the probability p (± Neg) as a function of the delay τ p (τ) = - cos2πр (± rel) [1, 4].

The number of ordinates determined for the normalized correlation function corresponds to the number n of cells of the ring distributor 1, and the discrete values of the arguments are multiples of the period of the clock generator 11.

The frequency range of the study of random processes can be changed by changing the frequency of the clock pulse generator 11, and changing the number of determined points of the correlation function by changing the number of triggers 2 ₁ -2 _n ring distributor 1.

As can be seen from the foregoing, the developed multichannel polar correlator has the simplicity of circuit design, high accuracy and provides the determination of both the correlation function of a random signal and the mutual correlation function of random signals.

Information sources

1. Zhovinsky V.I., Arkhovsky V.F. Correlation devices. M .: Energy, 1974.

2. Copyright certificate No. 327495, published January 26, 1972, Bulletin No. 5.

3. Copyright certificate No. 2210105, published August 10, 2003. Bulletin No. 22.

4. Bendat J. Fundamentals of the theory of random processes. M .: Nauka, 1965.

Claims (1)

A multi-channel polar correlator containing a ring distributor consisting of a clock pulse generator and serially connected triggers, the first inputs of which receive pulses from the generator, and the second input of each subsequent trigger is connected to the second output of each previous trigger, "n" keys, the first amplifier-limiter , the input of which is connected to the first input terminal by the first input signal, and the output - with the input of the first key, the first and second logical elements AND, a storage element, "n" counters , logical elements OR and NOT, while the output of the first trigger is connected to the control input of the first key and the first input of the first logical element And, from the output of the first key, the signal goes to the input of the storage element, from which the memorized polar signal goes to the first input of the second logical element And , also from the output of the first key, the signal directly goes to the first input of the OR gate, and to its second input through the logic gate NOT, from the output of the OR gate, the signal goes to the second input the first logical element And, from the output of which the signal is supplied to the first pulse counter, from the output of the second logical element And the signal through the corresponding public key, when the respective triggers of the ring distributor are sequentially activated, goes to the corresponding pulse counter, characterized in that in the ring distributor between "n" and the first trigger additionally includes an "n + 1" trigger, the second input of which is connected to the second output of the "n" trigger by the preparation signal, and its first output is connected to the control input of an additional "n + 1" key, the input of which is connected to the output of the storage element, and the output "n + 1" of the key is connected to the ground terminal, the second input terminal of the correlator is connected to the second input terminal via the second input signal through the second amplifier-limiter mode switch, and its first input contact is connected to the input of the first key, the output contact of the mode switch is connected to the second input of the second logic element I.