SU1206726A1 - Apparatus for measuring signal distortions in radioreceivers - Google Patents

Abstract

This invention relates to a radio measurement technique and can be used to monitor signal distortion. The purpose of the invention is to increase the reliability of the measurement by taking into account the additive component of the interference and phase fluctuations. The signal from the output of the generator (g) 1 signal is fed to the input of the generator 2 of the carrier frequency and carries out amplitude, frequency or phase

Description

a host carrier modulation, which is summed with the noise of the noise generator 4 in the adder 3. The voltage from the adder 3 is fed to the input of the studied radio receiver (MI) 19 tuned to the carrier frequency, and a demodulation operation is performed. The signal introduced is fed to the first input of multiplier 6, to the second input of which, through the first delay element 5 and attenuator 18, an undistorted signal is fed with G 1 "The output signal from multiplier 6 is sent to the input of the integrator 7. The voltage from the integrator 7 is recorded by a third measure. voltage (in) 15. In the second multiplier 8, the voltage from the integrator 7 is multiplied with the signal from G 1 and using the second

The invention relates to a technique of radio measurements and can be used to monitor signal distortion in radio receivers under the influence of interference.

The purpose of the invention is to increase the reliability of the measurement by taking into account the additive component of the interference and phase fluctuations.

The drawing shows a structural electrical circuit of the proposed device.

A device for measuring signal distortions in radio receivers contains a signal generator 1, a carrier frequency generator 2, an adder 3, a noise generator 4, a first delay element 5, a first multiplier 6, an integrator 7, a second multiplier 8, first and second subtraction blocks 9. and 10, a phase detector 11, a first voltage meter, a third subtractive unit 13, a second, third and fourth voltage meter, 14-16, a second delay element 17, an attenuator 18, also shows the radio receiver 19,

The device works as follows.

Before measurement, the proposed ycf function is calibrated to

06726

subtracting unit (WB | 10 the difference between the output signals of the IR 19 and the second multiplier 8 is calculated. The effective value of the interference component with the EB 10 is recorded by the fourth ID 16. The third EB I3 calculates the voltage difference with the IL 19 and 10. The signal c The output of the XB 13 is fed to one of the inputs of the phase detector 11, to the second input of which, via the first and second delay elements 5 and 17, a signal from G 1 is supplied. Delay elements provide a signal delay from G 1 equal to the delay of the signal transmitted through the MI 19 and WB 13. The signal from the phase detector 11 is fed to the first IN 12, which records the average phase shift and magnitude; NU phase fluctuations arising under the action of interference, 1il.

five

five

The conditions for measuring the multiplicative component of the disturbance at the output of the explored radio receiver 1 9. In the absence of interference, the amplitude adjustment at the output of the first multiplier 6 is performed by the attenuator 18, the phase adjustment by the first delay element 5.

 The moment of equality of the amplitudes and phases of the input signals of the first multiplier 6 is indicated by the minimum readings of the second voltage meter 14, to the input of which the voltage is supplied from the output of the first subtractive unit 9. Similarly, the delay of the signals at the inputs of the phase detector 11 is adjusted using the second delay element 17 - minimum values of the first voltage meter 12 in the absence of interference.

Multiplicative interference in the studied radio receiver 19 occurs under the influence of external radio interference. The mechanism for the occurrence of a slowly varying multiplicative co-interference is as follows: a powerful out-of-band interference penetrates the path of the studied radio receiver 19 and causes a change in the operating mode of its individual active elements and a change in the mode of operation of the automatic gain control circuits. In addition, a blocking effect appears.

These phenomena lead to slow changes in the multiplicative component of the disturbance at the output of the radio receiver 19 under study. The frequency at its output remains unchanged. 10

Thus, the conditions required to measure the multiplicative interference component of the correlation meter are satisfied.

The measurement is carried out as follows.

The signal S (t) from the output of the generator 1 is fed to the modeling input of the carrier frequency generator 2 and performs amplitude, frequency or 20 phase modulation of the carrier wave, which is summed with the noise of the noise generator 4 in the adder 3. The total voltage is fed to the input of the radio receiver under study 19, 25 tuned to the carrier frequency, and extracts the signal y (t) existed a demodulation operation:

y (t) / US (t) + f (t) -.

where W is a slowly varying multiplicative component of interference;

(t | - additive interference component uncorrelated with signal

The signal y (t) is fed to one input of the first multiplier 6, to the second input of which through the first delay element 5 and attenuator 18 an undistorted signal S (t) is fed, the output signal of the first multiplier 6

S (t) JU S (t) -1- (t) j

is supplied to the input of integrator 7, which has a transmission coefficient

one

E

one

where E is the signal energy S (t), which can be accumulated during integration of integrator 7,

As a result of the integration, the voltage at the output of the integrator 7 with an equal point estimate of 1 ° C - a multiple 1 L ikative component of the disturbance, the magnitude of which is recorded

the third voltage meter 15 iT is used as the result of the measurement rm.

| J5 (t) {p5 (t) .r (t)) Ji + i | 5 (i) (t) ji.

For stationary ergodic processes S (t) and (t), provided that the distribution density v (J is the probability of the instantaneous value of f (t)

relative to 0: i 1

symmetrical

t

J S (t) (t) dt O;

 g 2

J S (t) dt / "o

on

In the second multiplier 8, the value of - JV is multiplied by the signal S (t) and using the second subtraction unit 10, the difference of the output signals of the studied radio receiver 19 y (t) and the second multiplier 8 | U s (t) is calculated, is (t) - evaluation of the additive component of the noise, the effective value of which is recorded by the fourth voltage meter 16.

(us (t) + (t) (t) f (t)

the third subtraction unit 13 calculates the voltage difference y (t) and (t); as a result, at its output we have

result on

fiisCt)

0

five

0

five

ins (t) +5 f) -G () / ws {t),

which is fed to one input of the phase detector 1I, to the second input of which, through the first and second delay elements 5 and 17, the signal S (t) o

Phase detector 11 calculates the phase difference between the reference signal S (t) and the signal passing through the radio receiver under test (t). The first voltage meter 12 records the average phase shift and phase: fluctuations caused by interference. The first in, the second delay elements 5 and 17 bake the delay of the reference signal S (t), equal to the delay of the signal passing through the radio receiver 19 under study and the third subtraction unit 13,

Thus, the first voltage meter 12 registers the constant and fluctuation phases of the signal received by the radio receiver, the third voltage meter 15 registers the magnitude of the multiplicative component of the interference, the fourth voltage meter 16 registers the actual value of the additive component of the noise.

In addition, the proposed device is connected to the first multiplier, the first input of which is the output of the radio receiver under study, and the integrator, characterized in that, in order to increase the reliability of the measurement by taking into account additive interference with phase interference and phase fluctuations, the first and second delay elements, the first subtractive

It can be used for research of the unit, the first, second, third, and the quoting of the functioning of the radio receiver under study in a real electromagnetic environment. For this, noise generator 4 is replaced by an antenna and measurements are made of the multiplicative, additive components of the interference, phase distortions arising under conditions characteristic of the radio receiver under study.

The described procedure for measuring individual interference results is -. in parallel and does not require additional adjustments of the meter, which greatly simplifies and makes more accurate the process of measuring the quality indicators of the radio receiver under study.

Claims (1)

Invention Formula A device for measuring signal distortion in radio receivers, containing a series-connected signal generator, a carrier frequency generator and an adder, the output of which is the input of the radio receiver under study, an attenuator, a noise generator connected to another input by accumulators in series 20 25 Vertical voltage meters and serially connected second multiplier, the first input of which is the same as the integrator output, sec 15 and the third subtraction units and phase detector, the output and the second input of which are connected respectively to the input of the first voltage meter by the output of the second delay element, the input of which is connected to the output of the first delay element, the input of which is connected to the output of the signal generator, the first input of the first The multiplier is connected to the first input of the first subtraction unit with the second input of the second subtraction unit and the second input of the third extraction unit, the output and the second input of the first subtraction unit of the yen, respectively, with the input to If the voltage meter and attenuator output, the input of which is connected to the output of the first delay element and the second input of the second multiplier, the attenuator output is connected to the second input of the first multiplier, the integrator output is connected to the input of the third voltage meter, the output of the second rotating unit is connected to the input fourth voltage tester, Editor A. Shandor Compiled by E, Golub Tehred | M.Parotsay Order 8706/47, Circulation: Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5 Branch GOSH Patent, Uzhgorod, Proektna St., 4 The first multiplier, the first input of which is the output of the radio receiver under study, and the integrator, are different in that, in order to increase the measurement accuracy by taking into account additive co-interference and phase fluctuations, the first and second delay elements are introduced, the first subtracting block, first second, third and even vertimeter voltage meters and serially connected second multiplier, the first input of which is connected to the integrator output, the second and the third subtractive blocks and the phase detector, the output and second input of which are connected respectively to the input of the first voltage meter and the output of the second delay element, whose input is connected to the output of the first delay element, whose input is connected to the output of the signal generator, the first input of the first multiplier is connected to the first input of the first subtraction unit, with the second input of the second subtraction unit and the second input of the third subtraction unit, the output and the second input. the first subtraction unit is connected respectively to the input of the second voltage meter and the attenuator output, the input of which is connected to the output of the first delay element and the second input of the second multiplier, the output of the attenuator is connected to the second input of the first multiplier, the integrator output is connected to the third voltage meter input, the second output The snarling unit is connected to the input of the fourth voltage meter, Proofreader Oolugova