SU296061A1 - - Google Patents

Description

Devices are known for measuring the ratio of a signal to the effective value of a fluctuation disturbance during a television program transmission. However, the known devices do not provide the ability to measure the signal-to-interference ratio at any point in the moving image raster, thereby preventing separation of the interference introduced by the transmitting tube from the interference introduced by the communication channel; These devices also do not provide sufficient measurement accuracy due to the dependence of the measurement results on the image plot, and do not allow measurements in the color television path.

In the proposed device for measuring the ratio of the signal of fluctuation disturbance in any part of the moving image raster and increasing the accuracy of measurements, a block for storing and subtracting instantaneous values of neighboring samples is connected to the expander output, the signal from which is fed to the inputs of the multiplier unit and to the inputs of the key stage unit. The outputs of the block of key stages are connected to the input of the digital-to-analog converter, to the output of which the integrator is connected. In this case, the outputs of the multiplier unit are connected to the second Inputs of the block of key stages.

The operation of the device is based on the principle of modulating the instantaneous values of the video signal of short gating pulses (on the order of 20-30 nsec), following at a frame rate (or fields).

In this device, when measuring the effective value of the interference, the modulation can be performed by the level of a black or white video signal, i.e. that which does not change during the measurement cycle, as well as the instantaneous value of the video signal of the moving image. The ability to measure the effective value of interference with such modulation is based on the fact that there is a strong

the correlation between adjacent samples of the instantaneous values of the video signal of the image and the uncorrelatedness of the instantaneous values of the noise superimposed at the moments of the reference on the video signal.

This is achieved by forming the difference in neighboring samples, as a result of which the image signal is compensated and the interference is subtracted randomly. The resulting set of differences in instantaneous interferences is subject to further processing, as a result of which the effective value of interferences is determined from these differences. V / -2. O „h, V cycle; signal measurement cycle and interference measurement cycle. The drawing shows a block diagram of a device for measuring the ratio of a signal to fluctuation interference in any part of a moving image raster. The cycles are switched in the key stage i and in the block 2 key stages, the numbers of which are determined by the required YoilHocTbid measurements. The blocks are switched by pulses formed in the control unit 3. In the measurement mode, the disturbance of the key, cascade 1, which is part of the block 4 for forming narrow pulses, passes the signal coming from the generator output 5.; C, hell: r. .. ,, Evdt.,, The generator forms an impulse 4 sdz1 .. with a total value of 2U microseconds and is triggered by the front of a sync pulse line, in the signal interval of the image, select the e-shirel-alternate damping pulse in the Olok 6 selector circuit. The pulse coming from the output of the key stage 1, starts with a back edge of the generator 7 narrow pulses. The formed narrow pulse, which follows the frame rate or the frame rate, is fed to the input of the Mod - t-oracle -fixoAlttero-modulator block 9, to the other input of which a video signal is fed from the W input, the past through the weighing filter 11 and the switch. AZ . i gchku, cha, QQUH in the video signal there is no impulse that determines the control white level, then the impulse is formed in block 1o of the shape and entered into the video signal In this test case video signal is input-modulator - 8, passed -arevary through rezl l-oK ,, ..:.-..... ; :. ,,., ...,.;, .. To the input modulator - 8capable-block 15 of the controlled software binding, black level. -Multiply-Bindings-Formed In a block of 15strychnyh Snihro-Bros; in the cited from 6pages) Ideology Wb oki 6Selektora. 0TY IMPULSES-can be formed by -YY-by-ways MI, - -Natreimer way delays synchroMulSoB na-oradelen -NYyinterval. At the output of the modulator, 8 knots are formed, which are modulated by a signal from a moving image. The following frames and ILP fields Next, these pulses come to the input of the expander 16 — pulses. ... ..... Amplitude of each of the pulses At the output of the de-laxator.1b. Proportional Bna-Instant Video Spacing and Video Sigpal, sum ivfnpdB-aHHOfO with a temporary hindrance-interference. In | Transformation Tepe analogue of cd 17, which is included in the command of the Memorization and Subtraction unit -mighio wein; 1; There are one total count of 1 pulse of pulses with the number of pulses in each packet proportional to the range of the instantaneous value of the signal sulmmed with the instantaneous value of the disturbance. The formulated pulse packets are simultaneously applied to the input of reversible counters 19 and 20, which operate alternately in the modes of addition and subtraction. The switching control of these modes is decelerated in blocks 21 and 22, which are controlled by pulses generated in control unit 3. For example, when the pulse packet arrives in the first frame, the counter 19 operates in the addition mode, when the next pulse packet arrives in the second frame, the counter 19 operates in the subtraction mode, and the counter 20 in the addition mode. In the interval between the second and third frames, from counter 19 is captured and useful information in the form of the number of pulses recorded on the memory cells (in this case, triggers) and proportional to the difference in the instantaneous value of the video signal recorded in the first and second frames. Before the next batch of pulses arrives, the counter 19 is reset by the pulses generated in the control unit 3, and with the arrival of the burst in the third frame, the counter 19 is in addition mode, and the counter 20 is in subtraction mode. Thus, in the interval between the third and fourth frames, the counter 20 registers the number of pulses proportional to the difference of the instantaneous values of the signal, counted in the second and third frames. Not before the arrival of a burst of pulses in the fourth frame, the counter 20 is discarded, and with the arrival of the burst of pulses, this counter operates in the addition mode, and counter 19 in the subtraction mode. Further, the process of sequential storage of Instant Values - and subtraction of adjacent samples is periodically repeated; To obtain the absolute value of the difference in the number of pulses of ori. The subtraction indicator is provided at the counters in the control units 21 and 22. Thus, information from the counters 19 and 20 alternating with the pulse follow-up period is taken in the form of the number of pulses proportional to the difference of the instantaneous values of the interference counted in: the preceding ones. Further, these differences are between adjacent readings — the B-form-proportional number of -pulses, the enumeration-x in the лот view of the lenticals from the counter cells, are fed to the two inputs of the second block of the 23 -key cascades. The output of the block-key cascades of information is supplied to the input of the 24um-knife block and to the input of the block 2 "key-cascades.

The potentials at the output of the cells of the squaring unit 24 (in the reverse code), and in the measurement mode of the signal amplitude, the voltages corresponding to the voltages at the output of the second block 23 of the key stages are formed at the output of the stages.

The key stages of unit 2 are connected by their outputs to a digital-to-analog converter 25. From the output of the digital-to-analog converter, a signal proportional to the square of the absolute value of the difference of the instantaneous interference values is fed to integrator 26. Next, this voltage is applied to a logarithmic amplifier 27, which is built according to the principle “Modulation-demodulation. From the output of the logarithmic amplifier 27, a signal proportional to the logarithm of the effective value is fed to the input of the analog-code converter 28, which is part of the display unit 29. Further, the number of pulses, proportional to the logarithm of the effective value, is registered using a reversible counter 30, which is controlled by circuit 31, which is controlled by pulses from the output of control circuit 3. The counting direction changes when the measurement cycle is switched. In the interference measurement cycle, the counter 30 operates in the subtraction mode.

Before the measurement cycle of interference, the assumptions .. raeTdH cycle., Measure the signal. At the same time, at the end of the measurement cycle, the value in the binary numbering system is recorded on the memory cells of the counter 30, proportional to the logarithm of the span between black and white. The end of the interference measurement cycle includes a digital reading device 32, which converts the difference in the number of pulses, recorded in binary code on the memory cells of the counter, into a decimal code. The number in the decimal system, which represents the magnitude of the amplitude of the signal ratio to the effective value of the interference, is recorded on a digital scoreboard.

In the mode of measuring the amplitude of the signal in the selector block 6, a sync pulse line is located, in which there is a black-and-white voltage drop. The delay generator 33 generates pulses that follow with the frequency of the fields, the falling edge of which coincides with the black line interval, and the delay generator 34 — the pulses whose falling edge is in the interval of the white test line pulses. The pulses from the outputs of the delay generators 33 and 34 are supplied to the key stage 35, which is controlled by pulses from the output of the control circuit 3. In the interval of one field, the pulses from the generator 33 pass to the output of the key stage 35, and pulses from the output of the generator 34 pass to the output in another field.

On the L otor 8, the video signal modulates narrow pulses alternately with black and white levels. Further, the entire circuit operates similarly to the mode of measuring the magnitude of interference, except that block 2 of the key stages passes signals coming directly from the outputs of the key stages of block 23 to its outputs, i.e., block 24 of the multiplier min.

As a result, the number of pulses, proportional to the logarithm of the span between black and white, is recorded on the reversible counter 30.

In case there is no black and white differential in the test line, switch 12 turns on an additional circuit - a block for introducing a black and white control differential into the video signal. For this, the video signal from the output of the weighing filter 10 is fed to the input of the voltage-forming unit 36, equal to the swing of the video signal. After amplification, the signal goes to the integrator input. The voltage generated at the output of block 36 is fed to the input of the junction 37

white pulse formation. On the same block, from the output of block 6 of the selector, a sync pulse is delivered, in which the black-and-white differential must be replaced.

Under certain conditions, all major

conversions in the device can be performed digitally. This may be the case if it is possible to perform integration and logarithm operations in a digital manner. Since these operations

in digital form is rather cumbersome, they can only be performed by a universal digital computer. In this case, it is possible to program all operations that are performed after the cascade and perform all subsequent operations on the PC.

Subject invention

Device for automatic measurement

signal to fluctuation disturbance during TV program transmission, comprising a selector, a narrow pulse shaping unit, a weighting filter, a modulator, an expander, a black and white differential control unit, an integrator, a logarithmic amplifier, a display unit, a control unit, characterized in that , in order to measure the signal to fluctuation interference ratio in any part of the raster

moving image and improving the accuracy of measurements, the expander output is connected to the storage unit and subtraction of the instantaneous values of neighboring samples, the signal from which is fed to the inputs of the multiplier unit

and to the inputs of the unit of cascades, the outputs of which are connected to the input of the digital-analog converter, to the output of which the integrator is connected; the outputs of the multiplier unit are connected to the second inputs