SU964651A2 - Discrete communication channel simulator - Google Patents

Description

(SID SIMULATOR OF DISCRETE COMMUNICATION CHANNEL

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The invention relates to radio engineering and can be used for statistical analysis of noise immunity of discrete data transmission systems.

On the main auth, sv. No. 807312 is known a discrete communication channel simulator containing a modulo two adder, the output and first input of which is respectively the output and first input of the simulator, the synchronization unit, the first input of which is the second input of the simulator, and the output of the synchronization unit is connected to the input of the Markov generator the sequence, the first output of which is connected to the second input of the synchronization unit and the input of the random number sensor, the block of intermediate memory, the threshold adder and the And element, the output of which is connected to the second input adder modulo two, and the first and second inputs of the And element are connected respectively to the output of the threshold adder and the second output of the Markov sequence generator, the third output of which is connected to the first input of the threshold adder through the intermediate memory block, the second input of which is connected to the output of the Random Number sensor tl .

The disadvantage of the known simulator is that it simulates only transformation errors and does not take into account

10 edge errors that appear in the displacement of the edges of the transmitted symbol, which reduces the reliability of the simulation of a discrete channel.

The purpose of the invention is to increase the credibility of the communication channel simulation.

The goal is achieved by the fact that a signal edge driver, a control trigger, a switch, a decoder, an element: 3, a shift register, an additional Markov sequence generator, and an output trigger, a single input of the control trigger, are inputted into the discrete communication channel simulator. the driver of the pulses of the signal fronts is connected to the output of the modulo-two adder, the single output of the control trigger is connected to the control input of the prohibition element and the control input of the switch The information inputs of which are connected to the outputs of the additional Markov sequence generator, whose input is connected to the output of the synchronization unit, the switch outputs are connected respectively to the inputs of the decoder, the outputs of which are connected respectively to the bit inputs of the shift register, the information input of the prohibition element is the second clock input of the device and the output of the prohibition element is connected to the clock input of the shift register, the output of which is connected to the zero control input There are three trigers and a counting input of the output tri1-gera, the unit output of which is the output of the device. The drawing shows a block diagram of the device. The discrete communication channel simulator contains a synchronization block 1, a Markov sequence generator 2 an intermediate memory block 3, a threshold adder k, a random number sensor 5, element 6, an adder 7 modulo two, control trigger 8, backward 9 pulse the signal fronts, the switch 10, the element 11, the shift register 12, the decoder 13, the output trigger 1, the output of which is the output of the device, and the additional generator 15 of the Markov sequence. The device works as follows. The external sync pulse triggers block 1, which produces a signal that triggers the generators 2 and 15 of the sequence. At the first cycle of generator 2, a signal appears at its second output, which polls the element AND 6. Since nothing was fed to the inputs of the threshold adder, the input of element 6 will be low and the modulo two will not go to the input of the modulator . After the search cycle has been completed, Markov circuit status codes appear at the outputs of generators 2 and 15, the code at the output of generator 15 determines the value of the front shift, and code 9 14 at the output of generator 2 sets the cell address of memory block 3, in which the conditional probability of a transformation error is stored. At the same time, a signal appears at the third generator output of the second Markov sequence, which prepares unit 1 for a new cycle and interrogates the random number sensor 5, which produces a randomly even randomly distributed number. This number is fed to the first input of the threshold summer 4, to the second input of which the conditional probability of error arrives from memory block 3. A signal at the output of the threshold summat, k k, appears if the sum of the .components is greater than one. Thus, if all the conditions have been met, a unit appears at the input of AND 6. With the next pulse, generators 2 and 15 are started again, and the element 6 is interrogated at the second cycle of operation. As a result, an error signal appears at the output of element 6 and is fed to the input of modulator 2 modulo two, the output of which will be a mixture information symbols B with transformation errors. If, as a result of summation, a signal arrives at the input of the front 9, the output of the front side of the front 9 is a trigger, 8 is thrown into a single state, because in the initial position the triggers 8 and 14 were in the zero position. The signal from the single output of the trigger 8 interrogates the switch 10, which passes the front offset code from the generator 15 to the input of the decoder 13 and with the delay required to record 1 in one of the 2n-bits from the decoder 13 to the shift register 12, allows clock pulses to the shift input of the register 12. 1 in the p-bit de corresponds to an unbiased front, in the bit less than n, to the shift to the left, to the discharge, greater than n, to the shift to the right. 1, moved by clock pulses from the output of the shift register 12, flips trigger k to one and disables the clock pulses from the zero input of trigger 8. By processing the code for the falling edge, the device operates in the same way. The use of the invention allows modeling as transformation errors.

and marginal distortion, which leads to an increase in the reliability of modeling a discrete communication channel.

Claims (1)

1. USSR author's certificate No. 807312, cl. G About F 15/20; 1978