SU1124363A1 - Device for transmitting two signals via single communication channel - Google Patents

Abstract

TWO SIGNAL TRANSMISSION DEVICE FOR ONE COMMUNICATION CHANNEL, containing the first and second signal sources, the counting trigger, the phase modulator and the carrier generator, the output of which is connected to the first step of the phase modulator, the second output of the counting trigger, characterized by , in order to improve the transmission immunity, the first, second and third switching triggers, the first and second AND elements, the OR element, the first and second differentiating units, the first and second outputs according to the last of which is connected respectively to the first and second inputs of the first switching trigger, the first and second outputs of which are connected to the first inputs of the first and second elements AND, respectively, to the second inputs of which are connected the first inputs of the second and third switching triggers, respectively, to the first inputs of which the outputs are connected the first and second signal sources, the outputs of the first and second And elements are connected to the second inputs of the second and third switching triggers respectively and responsibly to the first and second (L inputs of the OR element, the output of which is connected to the first input of the counting trigger, the second output of which is connected to its second input, to the third inputs of the first and second elements, And connected to the output of the first differentiating unit, whose input is connected to the output of the carrier generator The output of the phase modulator is connected to the input of the second differentiating unit and is the output of the / device.

Description

one

The invention relates to automation and telemechanics and can be used in the development of information transfer devices by a phase-shifted signal from sensors of a number of pulsed irregular sequences along a single line on a common carrier.

Information transfer devices are known for phase-shift keyed signals from two information sources over a single communication channel, using the method of two-fold absolute phase and phase modulation (DAFM and). The DOFM transmitter in this case consists of two OFM transmitters in which the carrier has the same frequency, but differs for both sources in the channel in phase by 90 °, and cyi-iMaTopa, which adds the sum of the signals received at the outputs of the phase modulators.

Another option for constructing a DOPM transmitter is a circuit in which two initial binary signals of the first and second channels are converted into a quaternary signal according to a certain law, in accordance with the values of which the phase of the carrier frequency t1 is manipulated.

A common drawback of these devices, if they are used to transmit pulse numbers of irregular pulse sequences from two sources on a single carrier frequency, is the difficulty of their reliable separation on the receiving side due to the effect of the reverse operation when using a single pulse; relative modulation — an increase in the probability of failure by a factor of two and an even greater increase due to the fourth-order uncertainty for DOFM.

Closest to the present invention is a device comprising first and second signal sources, a counting trigger, a phase modulator and a carrier generator, the output of which is connected to the first input of the phase modulator, to the second input of which the first output of the counting trigger is connected , adder, phase shifter, second counting trigger and module TOP 2.

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A disadvantage of this device (as it is used for information transfer purposes, and for transmitting number-pulse irregular pulse sequences from two sources) is low noise immunity, still caused by a doubling of the likelihood of reception by the symbol in RPM

and an even greater increase in DOFM, due to fourth-order uncertainty in the reference voltage. In addition, for the transmission of number-pulse sequences, the circuit

This device is still complex, does not provide an unambiguous correspondence between the signals from both sources and the form of phase manipulations in the output signal of the device, and depending on the alternation of phase jumps of different magnitudes, the output signal spectrum significantly changes. asymmetrical with respect to the carrier frequency.

The purpose of the invention is to simplify the device and increase its reliability, i.e. Improved transmission immunity.

The goal is achieved by the fact that in the device containing the first and second signal sources, a counting trigger, a phase modulator and a carrier generator, the output of which

connected to the first input of the phase modulator, to the second input of which the first output of the counting trigger is connected, the first, second and third switching triggers, the first and second elements AND, the OR element, the first and second differentiating units, the first and second outputs of which connected accordingly

to the first and second inputs of the first switching trigger, the first and second outputs of which are connected to the first inputs of the first and second elements, respectively, to the second

the inputs of which are connected to the first outputs of the second and third switching, respectively, of the trigger, with the first inputs of which are connected to the outputs of the first and second sources

signals, the outputs of the first and second elements And are connected to the second inputs of the second and third switching triggers respectively and

respectively, the first and second inputs of the OR element, the output of which is connected to the first input of the counting trigger, the second output of which is connected to its second input, the third inputs of the first and second elements, and the output of the first differentiating unit, the input of which is connected to the output of the carrier generator, output The phase modulator is connected to the input of the second differentiating unit and is the code of the device.

The proposed device provides a significant increase in the reliability of reception of the number of pulsed irregular pulse sequences from two sources due to the formation of FM oscillations with a one-to-one correspondence between the source signals and the type of manipulation at the output of the transmission device, which is carried out without disturbing both the spectrum symmetry with respect to the carrier frequency and order of signals in time.

Figure 1 shows the structural electrical circuit of the proposed device, figure 2 - temporary. , diagrams of the work of its parts ..

The device contains the first differentiating unit 1, the carrier generator 2, the first source of 3 signals, the phase modulator A, the second switching trigger 5, the first element AND 6, the element OR 7, the counting trigger 8, the second source 9 of signals, the third switching trigger 10, the second element 11, the second differentiating unit 12, the first switching trigger 13.

The device works as follows.

The harmonic signal from the output of the generator 2 (Fig. 2a) goes to the first differentiating unit 1, at the output of which the pulses fix the extreme values of the derivative at the moments of half-voltage of the voltage of this signal through the zero level (Fig. 25).

A harmonic signal from the output of the modulator 4, which can take two mutually antiphase values, is fed to the second differentiating unit 12, the outputs of which separately generate pulses about the maximum (fig. 2a) and minimum (fig. E) derivative values. The outputs of this unit are connected to

separate inputs of the first switching trigger 13, which reproduces between the phase manipulations the output signal of the modulator 4 in the form of a meander. The pulse sequence at the output of the aforementioned trigger in terms of time parameters corresponds to the FM signal at the modulator output (Fig. Hi).

Let the output pulses of sources of irregular sequences include the corresponding triggers 5 and 10 on the intervals shaded in Fig. 2 and U, specially selected for

review critical modes of operation.

The frequency of occurrence of pulses from the source outputs for each of them should not exceed one period of the carrier frequency for any

source (in order to avoid their loss by quantity during transmission), and also not to exceed the same frequency between both sources (to avoid the same deficiency or violation of the order of their passage in time in the transmitted FM signal). Such subcritical / sequences are shown in 2j and and. .

At the moment of coincidence of the signal at the output of the trigger 5 (Fig. 2, after time point t), the signal at the direct output of the trigger 13 (Fig. 2) C) and the signal at the output of the first differentiating unit 1 (Fig. 25, the pulse is filled with a horizontal bracket ) an element of AND 6 is triggered, and the trigger 5 is reset by a pulse from its output, and through the element OR 7

The counter trigger 8, which controls the operation of the modulator 4, is transferred to the opposite state. Phase manipulation occurs in the region of the positive half-waves of the harmonic signal.

The described part of the device makes it possible to unambiguously carry out phase manipulations only in the region of the positive half-wave of the harmonic signal for the pulses coming from the first source 3, which is easily seen by analyzing the operation of the described part of the device for

S

moments of time tj, tj, t are similar to how this is done after time point t ,, and the minimum time between adjacent pulses from the first source must be not less than one carrier period in order for the manipulation in the FM signal (FIG. I , after the moments of time tj, tj) were generally possible and did not become double.

Let at time t (the distance between trt and t is also more than one carrier period) from the second source 9, a signal comes in, including a trigger 10 (Fig. 2m), the output of which is connected to the first input of the And 11 element. inverse trigger output 1 3 (FIG. 2 shows the signal at the forward output of this trigger) connected to the first input of the And 11 element, and the signal from the output of the first differentiating unit 1 connected to the second input of the And 11 element of the pulse from the output of the And output off the trigger 10 second source, and via email the OR 7 is transferred to the opposite state of the counting trigger 8, i.e. the phase is manipulated in the signal at the output of the modulator 4 in the negative half-wave region of the output harmonic signal.

The processes described after time point t are repeated in the same way when the second source 9 is pulsed, and they always correspond unambiguously to phase manipulation in the region of negative half-waves of the modulator output signal, which we convince by analyzing, for example, the operation of the device after the time point tj, t7.

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The unambiguous law of the formation of FM oscillations, in which only phase manipulations in the region of positive half waves and pulses from the second source correspond only to negative half waves, are possible for the pulses from the first source, first of all, due to the fact that analyzing the signal from the modulator output by determining its extreme values and activating the operation of the circuit is carried out synchronously with the half-periods of the carrier frequency. 15

Therefore, if the duration of the time intervals between the occurrences of at least one carrier period as from each source,

20 and from both of them, the proposed device allows the transmission of number-pulse irregular sequences from two sources via one line or channel.

25 communications on a single carrier frequency with respect to their priority in time and with an accuracy of at least one carrier period (for example, FIG. 22 after time points tj, t)

30 With a known signal propagation time in a particular communication channel, the proposed device can be used, for example, to synchronize dispersed two independent pairs of different types of devices, including digital versatile machines.

Almost all circuits of phase demodulators used are capable of restoring pulse-pulse irregular pulse sequences from two sources on one carrier.

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Claims (1)

DEVICE FOR TRANSMISSION OF TWO SIGNALS ON ONE COMMUNICATION CHANNEL, containing the first and second signal sources, a counting trigger, a phase modulator and a carrier generator, the output of which is connected to the first input of the phase modulator, the second input of which is connected to the first output of the counting trigger, characterized in that, with In order to increase the noise immunity of the transmission, the first, second and third switching triggers, the first and second AND elements, the OR element, the first and second differentiating blocks, the first and second outputs of the last about which are connected respectively to the first and second inputs of the first switching trigger, the first and second outputs of which are connected to the first inputs of the first and second elements respectively, And, the second inputs of which are connected to the first outputs of the second and third switching triggers, respectively, with the first inputs of which the outputs are connected the first and second signal sources, the outputs of the first and second elements AND are connected to the second inputs of the second and third switching triggers and g, respectively, to p the first and second inputs of the OR element, the output of which is connected to the first input of the counting trigger, the second output of which is connected to its second input, with the third inputs of the first and second elements AND the output of the first differentiating block is connected, the input of which is connected to the output of the carrier generator, the phase output. A new modulator is connected to the input of the second differentiating unit and is the output of the device.