SU1647904A1 - Data communication system - Google Patents

Abstract

This invention relates to communication and computing technology. Its use for transmitting messages over communication channels with interference improves accuracy and noise immunity. The system consists of the transmitting side 1, which includes the differential pulse-modulation modulator (DPCM) 4, the standard detection unit 5 and the clock pulse generator 7, the receiving side 2 containing the clock synchronization unit 10, the DPCM demodulator 14 and the reference restoration unit 13 and channel 3 communications. This goal is achieved by introducing pulses 6 at the transmitting side 1 and a distributor 8 pulses, and at the receiving side 2 - a receiver 9 discrete signals, a demultiplexer 11, a distributor 12 pulses and a low-pass filter 15. 3 hp f-ly, beat.

Description

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The invention relates to communication technology and computer technology and can be used to transmit messages over communication channels with interference.

The purpose of the invention is to improve the accuracy and noise immunity.

FIG. 1 shows a block diagram of the system; in fig. 2 is a schematic of a standard detection unit; in fig. 3 and 4 — multiplexer and demultiplexer circuits; in fig. 5 and 6 are diagrams of a unit restoration block and a differential pulse-code modulation demodulator (DPCM).

The information transmission system includes a transmission side 1, a reception side 2, and a communication channel 3.

The transmitting side 1 comprises a DPCM modulator 4, a reference detection unit 5, a multiplexer 6, a clock pulse generator 7 and a pulse distributor 8.

Receiving side 2 contains a receiver 9 discrete signals, a clock synchronization unit 10, a demultiplexer 11, a pulse distributor 12, a reference restoration block 13, a DICM demodulator 14, and a low-pass filter 15

The standard detection unit 5, when a certain amplitude value of the input signal (Fig. 2) is taken as the reference, can be performed on the comparator 16, the reference voltage source 17, the HE element 18, the repeater 19 of the first and second differentiating elements 20 and 21, the element OR 22 and the imaging unit 23 pulses.

The multiplexer 6 (FIG. 3) is AND 24 elements and the OR 25 element. The demultiplexer 11 (FIG. 4) contains AND elements 26.

FIG. 3 and 4, the graphical arrangement of the inputs and outputs of the blocks 6 and 11 correspond to FIG. one.

The standard restoration unit 13 for the indicated example (Fig. 5) consists of the source 27 of the reference voltage and the key 28. The DPCM demodulator 14 (Fig. 6) contains the first and second sources 29 and 30 of constant voltage, the first and second keys 31 and 32 and divider 33 voltages.

The system works as follows.

Discrete or analog messages are sent to the input of the system in the form of analog signals. At the same time, the input signals contain previously known repeating reference values, for example, in the form of amplitude values.

Thus, the values can be, for example, the average levels of signals with respect to which the signals of analog messages change or the minimum and maximum values of signals of discrete messages.

The input signals of the system are converted into discrete signals of the two-digit increments in the modulator 4 of the DPCM, which through the multiplexer 6 enter the channel 3 of the connection. At the same time, the input signals are sent to the standard detection unit 5, where

0 is compared on a comparator by an Unspecified threshold in advance from source 17. When the reference value is received through multiplexer 6, the communication channel 3 sends an eq value to the incremental signal instead of incremental signals. Thus, discrete increment signals of two characters received at receiver side 2 by receiver 9 are fed through demultiplexer 11 to demodulator 14 for recovering the output signal. When i exit from the output of communication channel 3, the reference value of the reference value goes to recovery block 13 reference. The signal from the output of block 13 sets the output

5, the system signal in accordance with a predetermined amplitude value of the standard This is achieved by correcting the distortion of the current value of the output signal, which occur when possible failures.

0 discrete incremental signals,

The system of signal transmission of discrete and analog information corrects the arising distortions of channel premises in the presence of transmitted

5 signal repetitive a priori known reference values. Such a priori reference values may be the previously known values of the input signal amplitude, velocity, or frequency of variation. For example, in the case of detection of a given amplitude, the standard detection unit 5 can be made as a comparison of the input signal with a previously known threshold, when

5 from which the output of block 5 to channel 3 of the communication receives a special information signal about the occurrence of this reference value.

Considering that the system is designed to transmit input signals with a limited number of reference values, each of which is transmitted to the receiving side by a special unambiguous information signal, for transmission

The last 5 in the channel message is allocated such a separate combination of pulse signals of increments, which differs from the signals of increments when the values change. For example, if the clock interval for a DPCM signal is positive

or negative increments are transmitted by separate pulse signals placed in previously known parts of the clock interval, a one-time signal about the occurrence of a reference value can be transmitted from the output of block 5 of transmitting side 1 with the simultaneous presence of signals of increments of both characters Received from link 3 the reference value signal at the receiving side 2 is allocated at the first output of the demultiplexer 11 and is fed to the reference recovery unit 13. The output signal from block 13 as this reference value is fed to the input of low pass filter 15.

This one-time signal achieves a fixation of the reference value of the reference amplitude at the output of the system. When the input signal reaches the reference value repeatedly, this value is restored at the output of the system according to an individual one-time signal. If it is necessary to fix other reference values, it is necessary to use a single signal that is different from those previously used. If there are no reference values in the transmitted signals, no correction is made to the output signal.

Thus, the accuracy and noise immunity of the system is improved.

Claims (4)

1. An information transmission system comprising a communication channel, on the transmitting side — a differential pulse code modulation modulator, the input of which is combined with the input of the standard detection unit and is the system input, clock generator, on the receiving side — a clock synchronization unit, a differential pulse-code modulation demodulator, and a standard recovery unit, characterized in that, in order to improve accuracy and noise immunity, a multiplexer and pulse distributor are inserted on the transmitting side, The clock pulse output is connected to the first control input of the multiplexer and the pulse distribution input, the outputs of which are connected to the second control inputs of the multiplexer, the outputs of the modulator of the differential pulse code modulation and the output of the standard detection unit are connected to the first and second information the multiplexer inputs, a receiver of discrete signals, a demultiplexer, a pulse distributor and a low-pass filter are input on the receiving side, the output of the clock synchronization unit is connected with the clock input of the receiver of discrete signals, the first control input of the demultiplexer and the input of the pulse distributor whose outputs are connected to the second control inputs of the demultiplexer, the output of the receiver of discrete signals is connected to the information input of the demultiplexer, the first and second outputs of which are connected to the inputs of the demodulator differential pulse code modulation and the input of the standard restoration unit, the outputs of which are connected to the input of the low-pass filter, the output of which is the output of the systems , The multiplexer output on the transmission side through the communication channel connected to the data input of the receiver input signals and discrete clock synchronization unit on the reception side. 2. The system of claim 1, wherein the reference detection unit is made on the comparator, the reference voltage source, the NOT element, the repeater, the differentiating elements, the OR element and the pulse driver, the first input of the comparator is the input of the unit, the output of the reference source voltage is connected to the second input of the comparator, the output of which is connected to the inputs of the element NOT and a repeater, the outputs of which through the first and second differentiating elements are connected to the first and second inputs of the element OR, the output of which through A pulse driver is connected to the output of the unit. 3. The system of claim 1, wherein the differential pulse code modulation demodulator comprises DC sources, keys and a voltage divider, the control inputs of the first and second keys are the corresponding inputs of the demodulator the outputs of the first and second sources of voltage are connected to the information inputs of the keys of the same name, the outputs of which are connected to the first and second inputs of the voltage divider, the output of which is the output of the demodulator. 4. The system of claim 1, wherein the reference restoration unit comprises a key and a source of voltage reference, the output of which is connected to the information input of the key, the control input and output of which are respectively the input and output of the unit. Phage. five 5 4