SU1339580A1 - Device for simulating errors in digital information transmission channel - Google Patents

Abstract

The invention relates to specialized means of computing and can be used in the experimental study and testing of digital transmission system equipment. The purpose of the invention is to expand the functionality of the device by simulating errors in digital information transmission systems with quasitrotic signals. The device includes a noise generator 1, a limiter 2, a driver of 3 error pulses, triggers 4, 5, input 6 and output 10 matching linear transformers, elements HE 18, 8, OR 9, 11, 12, 19, switches 7, 17, meter 13 ratios, digital-to-analog converter 14, transmitter 16, receiver 20 and display unit 15. The device makes it possible to simulate errors in quasi-troc blackfish. These are used to transmit information over the linear path of digital transmission systems. In addition, the device can work with both unipolar binary signals and bipolar binary linear signals j used in some types of digital transmission systems. 1 il. i L with so with sd 00

Description

The invention relates to specialized means of computing and can be used in experimental research and testing of digital transmission systems using quasi-tropic signals (three-level transmission codes) in a linear path.

The purpose of the invention is to expand the functional capabilities of the device by simulating errors in digital information transmission systems with quasitrotic signals. The drawing shows a structural electrical circuit of a device for modeling errors in a digital information transmission channel.

The device contains a noise generator 1 5 limiter 2, driver 3 error pulses S second trigger 45, first trigger 5, input matching linear transformer 6, first switch 7, first element NO 8, first element OR 9, output matching linear transformer 10, third element OR 1 is the fourth element OR 12, the ratio meter 13, the digital-to-analog converter (DAI) 14, the display unit 15, the transmitter 16, the second switch 17, the second element NOT 18, the second element OR 19, and the receiver 20.

The device works as follows, /

A sequence of quasi-linear linear signals (any of the three-level or bipolar transmission codes) from the transmitter 16 of the digital transmission system is fed to the input of the linear transformer 6, the output winding of which has a grounded midpoint and its outputs are connected to two identical chains consisting of switch 7, the first the element HE 8 and the element OR 9, (or G /, 18 and 19), which are intended to introduce errors into a sequence of quasi-black signals split by the input linear transformer 6 into two parts ear level

These two-level (unipolar) sequences arrive at the first input of the corresponding switch 7 or 17, which, when exposed to a sequence of pulses formed according to a given law, from the output of the trigger 5 with the counting input, switches the outputs. Gay

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noise generator 1 produces noise voltage. Limiter 2 forms a random sequence of pulses, the frequency of which depends on the level of the limit. A random sequence of pulses from the output of limiter 2 is fed to the input of the imager 3 error pulses, the output of which forms a sequence of short pulses, grouped according to a certain law. This sequence of pulses goes to one input of the flip-flops 4, the other input of which is faulty and is connected to the output of the AND, LI 1 1 element to fix the end of the introduction of each distortion. From the output of trigger 4, a random sequence of pulses is fed to the counting input of trigger 5, from the output of which a sequence of pulses with a random duration is fed to the control inputs of switches 7 and 17, both chains, which form errors in the information sequence. Switching the outputs of switches 7 and 17 in accordance with the duration of the pulses at their control input occurs so that the corresponding two-level sequence of pulses passes through either the first element HE 8, (18) and the element OR 9 (19), which provides an imitation of the suit- polarity in the communication channel or direct

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without distortion passes through the elements OR to the linear transformer 10,

The linear transformer 10 combines the two two-level components into a single three-level linear signal, the individual elements of which are distorted, and outputs this information sequence to the receiver 20 of the digital transmission system.

At the same time, the input signals of both components of the information signal from the outputs of the linear transformer 6 through the element OR 12 are fed to one input of the ratio meter 13, to the other input of which are fed through the element OR 11 distorted signals from the outputs of the elements NOT. The meter 13 determines the magnitude of the error rate at a given analysis interval, which is converted by the DAC 14 into the control voltage of the threshold of the limiter 2.

Claims (1)

A device for modeling errors in a digital information transmission channel, comprising a first switch, the first output of which is connected to the first input of the first element OR the second output of the first switch is connected to the input of the first element NOT, the output of which is connected to the second input of the first element OR, controlling the input of the first switch is connected to the direct output of the first trigger, the ratio meter, the output of which is connected to the information input of the digital-to-analog converter, the output of which It is connected to the input of the limiter signal level, the information input of which is connected to the output of the noise generator, and the output of the limiter is connected to the input of the pulse error generator, characterized in that, in order to extend the functionality by simulating errors in digital information transmission systems with quasitroic signals, it additionally contains input and output matching linear transformers, the second trigger, the second, third and fourth elements OR the second element NOT and the second switch If, moreover, the primary windings of the input matching linear transformer are inputs of the device, the secondary windings of the input matching linear transformer are connected according to A. Borovich Order 4224/40 Compiled by V. Fukalov Tehred M. Didyk Proofreader M. Dekchyk Circulation 672 Subscription VNISHI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 controlled by the information inputs of the first and second switches, control jupe (the second input of the second switch is connected to the direct output of the first trigger, the first output of the second switch is connected to the input of the second element NOT, the output of which is connected to the first input of the second element OR, the second input which is connected to the second output of the second switch, the outputs of the first and second elements OR are connected to the terminals of the primary winding of the output matching linear transformer, the conclusions of the secondary winding of which are outputs The device, the outputs of the first and second elements are NOT connected respectively to the inputs of the third element OR, the output of which is connected to the zero input of the second trigger and the first information input of the ratio meter, the second information input of which is connected to the output the fourth element OR, the outputs of which are connected respectively to the terminals of the secondary winding of the input matching linear transformer, the output of the driver of error pulses connected to the single input of the second trigger, the direct code of which is connected to the counting input of the first trigger, the secondary point of the secondary winding of the input matching line transformer and the primary point of the primary winding of the output matching line transformer are connected to the zero potential bus.