SU1734045A1 - Device for measuring characteristics of random processes - Google Patents

Abstract

Use: in radio measuring equipment when determining parameters of communication channels and research of radio engineering devices. The purpose of the invention is to improve the accuracy of determining the difference between the random process under investigation and the normal distribution law. SUMMARY OF THE INVENTION: The device comprises a serially connected normalizing amplifier 1 linear detector 2 controlled nonlinear element (UNE) 3, first integrator 4, the output of the NOEL is connected to the input connected in series to separation capacitor 15, quadratic detector 7, second integrator 8, nonlinear element (HE) 9 with the characteristic Y Vx, the output is NOT connected to the splitter input 10; the output of the subtractor 11 is connected to the divider input; the outputs of the first integrator 4 and sensor are connected to the inputs of which 11 of the reference voltage, the output of the divider is connected to the input of the comparator 13, the output of which is connected to the address input of the switch 5, the first and second inputs of which are connected to the outputs of the first integrator and the sensor of the reference voltage respectively, and the output is connected to the input of the first indicator to the output of the comparator. 1 il.

Description

T

s

О About

The invention relates to a radio measuring technique and can be used to identify ergodic stochastic processes, in particular, in determining the parameters of communication channels and in the study of radio engineering devices.

A device for measuring the characteristics of random processes is known, comprising a splitter, a delay line, a selector, an adjustable amplifier, discriminators, a selection unit, a coincidence unit, a control unit, a recorder, a register, a back-bit circuit, and an address generator.

However, this device has narrow functionality.

Closest to the present invention is a device for measuring the characteristics of random processes, comprising a normalizing amplifier, two quadratic detectors, a double quadratic detector, two integrators, a divider, an arithmetic subtractor, and an indicator.

The known device makes it possible to determine the difference between the probability distribution law of the amplitude of the random process and the normal law only for fourth-order moments, which limits the possibility of using more accurate measurements, if necessary, than the normal distribution law.

The aim of the invention is to improve the accuracy of determining the differences in the distribution law of a random variable from the normal distribution.

The goal is achieved by the fact that a device for measuring the characteristics of random processes, containing a normalizing amplifier whose input is an input of the device, a linear detector, a quadratic detector, the first integrator, the first indicator, a subtractor and a divider, a controlled nonlinear element, a switch, a second integrator , a coupling capacitor, a second integrator, a coupling capacitor, a nonlinear element with a characteristic U Vx, a reference voltage sensor, a comparator and a second indicator, with the normalizing voltage A linear detector, a controlled nonlinear element, and a first integrator are connected in series, the output of a controlled nonlinear element is connected to a serially connected separation capacitor, a quadratic detector, a second integrator, a nonlinear element with a Y Vx characteristic, the output of which is connected to a divider input, an input the dividend of which is connected to the output of the subtractor, whose inputs are connected to the outputs of the first integrator and the sensor of the reference voltage, the output of the divider is connected to the input the comparator, the output of the divider is connected to the input of the comparator, the output of which is connected to the address input of the switch, the first and second inputs of which are connected to the outputs of the first integrator and the voltage sensor, and the input of the second indicator is connected to the output of the comparator.

The drawing shows a block diagram of a device for measuring characteristics of random processes.

The device contains a normalizing

amplifier 1, linear detector 2, controlled non-linear element 3, integrators 4 and 8, switch 5, indicators 6 and 14, quadratic detector 7, non-linear element

9, a divider 10, a subtractor 11, a reference voltage sensor 12, a comparator 13 and a coupling capacitor 15.

Absolute

moments of the v-th order of a random variable normalized to the variance

+ 00 j

E (-I / / X / p (x) dx,

- 00

(one)

where x is the value of the input random variable;

(p (x) is the density distribution of the likelihoods of a random variable.

The normalization condition is written as

E (2) 1.

(2)

4Q The normal distribution law has the following absolute moments.

five

Yong (v) v

(3)

I 2

A device for measuring the characteristics of random processes works as follows.

The switch on the controlled non-linear element is set to v 2, and the voltage value is set to the conventional unit on the sensor of the reference voltage. The investigated electrical signal x is fed to the input of amplifier 1, where it is amplified and normalized to a conventional unit, from the output of the normalizing amplifier 1, the signal under study is fed to a linear detector 2, which operates as a full-wave rectifier, from the output of the linear detector 2, the rectified signal is fed to the input controlled nonlinear element 3, the amplitude characteristic of which is determined by the expression

Y-x.

(four)

From the output of the controlled nonlinear element 3, the signal is fed to the input of the integrator 4, which is made with adjustment of the integration time to change the accuracy of measurement of moments, the output of the integrator 4 is an estimate of the absolute moment that goes to the 1st input of the switch 5 and to the 1st input subtractor 11, to the second input of which receives a signal from the sensor 12 of the reference voltage, which is generally determined by the expression

U

supports

 a EH (v),

(five)

where a is conditional unit,

From the output of the subtractor, the difference (g (EISm. (2) - En (2) | goes to the divisible input of the divider 10, the sharing input of which receives the signal for estimating the standard deviation of the measured moment,

case of her (2). The calculation of the standard deviation is implemented by a quadratic detector 7, the second integrator 8 and the nonlinear element 9, the centering is performed by the coupling capacitor 15. The output signal of the divider is a level

I (2) - EN (2)

L (2) ООООО

(6)

which is fed to the input of comparator 13, where it is compared with the threshold level Unop, which sets the confidence interval of the estimate, with L (2) Unop at the output of comparator 13 is set to one, and with L (2) Unop - zero. The signal at the output of comparator 13 connects with L (2) Unop is the output of integrator 4 to indicator 6, and for L (2) Unop is the output of sensor 12 of the reference voltage, while the indicator 14 also coincides, which means Eism (2) En (2), i.e. end of normalization. For convenience of signal normalization by dispersion, the normalizing amplifier 1 can be adjustable, the switch determining the value v of the controlled nonlinear element 3 also determines the signal at the output of the sensor 12 of the reference voltage, the integrators 4 and 8 are made with

by common adjustment of the integration interval, Unop is also regulated.

When v 2, the device works in the same way. If Eism (v) b (En (V - Unop tf (v); En (v) + Unop o (v), then L (v) Unop, indicator 6 indicates the value EH (v), since En (v) and Eism (v) are non-distinct in the sense of a confidence interval defined by Unop. IF Eism (V) {Yong (V) - Unop

x (j (v); En (v) + Unop o (, TO indicator 6 indicates the value

Eism (v), L (v) Unop.

With the coincidence of Eism (v) and En (v) in the sense of a confidence interval, i.e. when L (v) Unop, the match indicator 14 is turned on.

With v 4, the device provides a prototype mode of operation, namely, it determines the difference in the excess, and for others, v provides additional information about the difference from the normal distribution law.

An increase in the accuracy of measurement of the difference between the studied distribution law and the normal one is achieved due to additional information on the values of the moments of higher orders, which is estimated by you.

razheniem

I Eizm (v) - En (v) / v Udop SO%

5) EISM (v) -EH (V) / V

2

where T max is such a value v such that for any v vM3Kc, L (v) Unop holds. - Determined by vMaKc from the expression for the relative measurement error of the difference in individual moment of order v

(,) K (,), (8)

where (v) / lrxV (t) -E (v)} dt;

AE (v) I EN ° (At Eism (V) I;

maximum at D0p max is reached at

Unop Tin 0 674 And At T T max

Claims (1)

An apparatus for measuring the characteristics of random processes, comprising a normalizing amplifier whose input is the device input, a linear detector, a first integrator, a first indicator, a quadratic detector, a subtractor and a divider, characterized in that, in order to improve the accuracy of determining differences distribution of a random variable from a normal distribution, a controlled nonlinear element, a switch, a separation capacitor, a second integrator, a nonlinear element with the character Stick Y Vx sensor reference voltage, a comparator and a second indicator, wherein the normalizing amplifier, a linear detector is controlled by the first nonlinear element and an integrator connected in series, the output of the nonlinear element controllably connected to a decoupling capacitor connected in series, a quadratic detector, the second integrator, a nonlinear element with a characteristic Y V whose output is connected to a divider input, the divisible input of which is connected to the output a subtractor, the inputs of which are connected to the outputs of the first integrator and the voltage-sense sensor, the output of the divider is connected to the input of a comparator, the output of which is connected to the address input the switch, the first and second inputs of which are connected to the outputs of the first integrator and the reference voltage sensor, respectively, and the output is connected to the input of the first indicator, the input of the second the indicator is connected to the output of the comparator,