SU472469A1 - Data transmission system with information feedback - Google Patents

Description

but

The invention relates to the field of telegraph communication.

A data transmission system with information feedback is known, comprising a message sensor, one output of which is connected via the Forward channel to the first input of the output device, a back channel connected to the first input of the comparison unit, and a control unit.

A disadvantage of the known system is a relatively low noise immunity.

The purpose of the invention is increased noise immunity.

This is achieved by the fact that the second forward channel output through a serially connected delay block and a module 2 module is connected to a reverse channel, and the second output of the message sensor is connected via a serially connected other delay block and to a module two terminal connected to the second input of the comparator unit, output through a serially connected decoder and control unit connected to the input of the message sensor.

The drawing shows a block diagram of the proposed system.

The circuit contains a message sensor 1, forward channel 2 communication, output device 3, delay blocks 4 and 5, adders 6 and 7, reverse communication channel 8, comparison unit 9, descrambler (error separation block by channel) 10, control unit eleven.

For the sake of impliedness, we consider the case of meaningful verification as being different, with one

hand, simplicity of technical implementation and efficiency in relation to the average number of repetitions per message element and, on the other hand, minimal noise immunity (the possibility of coding is excluded).

Messages from the sensor output of message 1 arrive at the input of the direct channel 2 and simultaneously at the input of the block of the delay 5. The output of the direct channel receives the received messages successively into the output device 3, where they are stored and after a certain time for this system are given to the crawler. At the same time (similarly to the transmitting side) they enter the delay block 4, the capacity of which is t messages.

The reception of each message causes the information to advance along the delay block 4. In this case, from the output of the cells, the information is read and fed to the adder 6, where it is summed modulo the base of the applied code. The result from the output of the adder 6 is transmitted on the reverse channel 8 for testing. Thus, the receipt for each received message is the result of summing this message with

t-1 previously received (always t messages).

In other words, a receipt is formed on the principle of sliding summation with a block / message length.

From the output of the reverse channel, the messages arrive at the input of the comparator unit 9, where they are compared with the result from the output of adder 7, which is formed according to the same rule by the receiving party from the undistorted messages and delayed by the propagation time signal.

The impulses of errors from the output of the comparison block 9 are fed to the input of the decoder 10, whose task is to separate the distortions but the channels and determine the nature of the distortion if the number of positions of the applied stroke is more than two (). Obviously, in this case, error pulses, in contrast to binary coding, must be distinguished by additional features (for example, level, duration, etc.), the number of which is equal to the number of possible distortions.

The basis of the work of the decoder is the fact that with such a system construction, the nature of the distortions (only in the forward, only in the reverse, in the forward and reverse channels at the same time, as well as their different combinations within the addition step t) are different by the structure of the group of error pulses from the output of the comparison block. At the same time, the probability of error of channel error separation in the worst case does not exceed the value of ro or ro, where the probability of distortion of the message element

in the forward symmetric binary channel, RO - in the reverse.

After decrypting the address of a message corrupted in the forward channel from the output of the decoder 10 via the control unit 11, a command is sent to the sensor of messages 1 either to send an erase character (during sequential correction) or to remember the corresponding address to be repeated for address correction of text.

Subject invention

A data feedback data transfer system comprising a message sensor, one output of which is connected via a forward channel to a first input of an output device, a reverse channel connected to the first input of a comparison unit, and a control unit, characterized in that second noise immunity

the output of the forward channel through a serially connected delay unit and a modulo two adder is connected to the reverse channel, and the second output of the message sensor is connected via a serially connected other delay unit and the modulo two adder is connected to the second input of the comparison unit, the output of which is connected through a serially connected decoder and the control unit is connected to the input of the message sensor.

Boixod