SU1674149A1 - Device for simulating communication system - Google Patents

Abstract

The invention relates to computing and can be used to model communication systems with variable parameters. The purpose of the invention is to improve the accuracy of modeling. This goal is achieved by introducing additional AND elements, pulse counters, decoders, triggers, a switch, and an I. element block. The device allows you to simulate a wide class of systems with multi-element repeating messages in communication channels with arbitrary error statistics. 1 il.

Description

The invention relates to computing and can be used to model communication systems with variable parameters.

The purpose of the invention is to improve the accuracy of modeling.

The drawing shows the functional diagram of the device.

The device includes a generator of 1 clock pulses, a generator 2 of a random stream of pulses, an element of NOT 3, a switch 4, a first element of AND 5i, a third through (n + 1) elements of AND 5h - 5n-n, a group of pulse counters, decoders 7i - 7h. block 8 switches, triggers 9i-9n, block of elements AND 10, second element And 11, pulse counter of correctly received messages 12, divider 13 of frequency of pulses, pulse driver 14 of pulses, pulse counter of 15 transmitted messages, display unit 16.

The device works as follows.

Generator 1 models the sequence of message elements. In this case, a further sequence of pulses simulates the transmission of the n-element message. Switch 4 can be a ring type shift register that the unit moves in, providing an enable signal from the switch output to AND 5 cells in turn. The switch bit corresponds to the number of elements in the message and is equal to n. At the initial installation from the setup input, switch 4 is set in such a way that the first bit is in the unit state, and the other bits are in the zero state. The first input of elements And 5 receives pulses from generator 1, and their second inputs - signals from generator 2 through the element NOT 3. Suppose that there is no error at the time corresponding to the i-th element of the message. In this case, from switch 4, from its 1st output, to the i-th element I 5, I allow

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elohunga Ml. 3 also (if there is no error from generator 2, which simulates the error flow), the enabling signal is received, and the pulse from generator 1, passing through the corresponding AND 5 element, adds one to the contents of the corresponding counter 6. Thus, the corresponding counter records how many times this The message element was transmitted without distortion. If at the moment of simulating the transmission of a message from generator 2, an error signal is received, the enabling signal from the NOT element is removed from the corresponding element AND, and the state of the corresponding 1st pulse counter does not change.

The switch box sets the parameter for majority reception. It can, in particular, be made on the basis of a multi-position switch composed of similar switches for each element.

When the pulse counter of the 1st element reaches a certain selected number, as a rule, more than half the counter capacitance, a signal appears at the corresponding output of the decoder connected to it, and through the switch block sets in one state the corresponding trigger, indicating that This message element is received correctly.

If a k-fold transmission of a message is simulated, the divider 13 is rearranged by the user so that it has a division factor k. Thus, after the n-k pulses, which corresponds to the k-fold transmission of the n-element message, a signal appears at the output of divider 13, which increments the contents of the pulse counter 15, which is intended for counting of the transmitted messages. Simultaneously, the signal from the splitter 13, which passed through the pulse shaper 14, which is used to form a shortened pulse width, interrogates the element 11. In the case when all elements of the message are received correctly, all the triggers are in the unit state and at the output of the element And 10 there is a signal that, having passed through the element 11, adds one to the contents of the counter 12 pulses, designed to record correctly received messages. If at least one of the message elements is received incorrectly, the corresponding trigger is in the zero state and the signal at the output of the And 10 element is absent, which corresponds to the fact that this multi-element message received an error.

The pulse from the imaging device I 4 pulses also goes to the counters and resets

them to the zero state, after which the modeling of the transmission of the next multi-element message begins. If it is necessary to change the parameters of the device or to stop the experiment, a signal is set to the installation input of the device. In this case, the divider 13 and the counters 12, 15 are set to the initial (zero) state, and the switch 4 is set to such a state when the single unit is in the first rank.

Claims (1)

Claims An apparatus for modeling a communications system, comprising a clock generator 0 pulses, random pulse generator, element NOT, first pulse counter, pulse counters of correctly received and transmitted messages, first decoder, switch block, first 5 three g er, the first and second elements And, the pulse frequency divider, the pulse shaper, the display unit, the output of the clock pulse generator connected to the first input of the first element And, the output 0 generator of a random stream of pulses connected to the input element NOT, the output of which is connected to the second input of the first element AND whose output is connected to the counting input of the first pulse counter, the output group of which is connected to the corresponding group of information inputs of the first decoder, the output group of which is connected to the corresponding the first group of information 0 inputs of the switch block, the first output of which is connected to the single inputs of the first trigger, the zero input of which is connected to the output of the second element And the counting input of the pulse counter of correctly received messages, the output group of which is connected to the first group of information inputs of the display unit, the divider output the frequency of the pulses is connected to the input of the pulse former and 0 by the counting input of the pulse counter of the transmitted messages, the output group of which is connected to the information inputs of the second group of the display unit, the output of the pulse generator is connected to the installation input of the first pulse counter and the first input of the second element I, the installation inputs of the pulse counters of correctly received and transmitted messages and the splitter pulse frequencies are combined and are the installation input of the device, characterized in that, in order to improve the accuracy of the simulation, n elements AND, pp of p-1 counters, p-1 decoders, p-1 flip-flops, a switch and a block of elements And, the first input of the j-ro element I (where j 3-p) is connected to the output of the clock generator, the second input of each J- The ro element I is connected to the output of the element NO, the third input of each J-ro element I is connected to the corresponding output of the switch, the output of each J-ro element I is connected to the counting input of the corresponding pulse counter of the group whose outputs are connected to the group of information inputs of the corresponding decoders, the group the outputs of each of the ko oryh connected to a group of information vho0 five Dov block switches, each of K (where K - 2-p) of the outputs of which is connected to a single input of the corresponding trigger, the output of each of which is connected to the corresponding input of the block of elements And, the output of which is connected to the second input of the second element And whose output is connected to the zero input of each of the K triggers, the output of the pulse generator is connected to the installation input of each i-pulse counter (I 2- (p-1)), the output of the clock generator is connected to the information input of the switch, (n + 1) -th output of which connected to the counting input of the pulse frequency divider, the control input of the switch is connected to the installation input of the device.