SU1117841A1 - Device for providing impulse noise protection when synchronous receiving of pulse signals - Google Patents

Abstract

DEVICE. PROTECTION AGAINST PULSE INTERFERENES AT SYNCHRONOUS RECEPTION OF PULSE SIGNALS, containing an input pulse shaper, a clock generator and connected in series the first element OR, the first trigger and the first element AND, ... diff. By the fact that, in order to reduce the noise immunity, the first inverter was inputted into it, the input and output of which are connected respectively to the first output of the clock / pulse generator and the first input of the first IPI element, connected in series to the second inverter, whose input is connected to the second output of the clock pulse generator , the second element AND, the output of which is connected to the second input of the first element OR, the second element OR, the second trigger, the other input of which is connected to the output of the first element AND, the third element AND, the other input which is connected respectively with the first output of the clock, the output of the second inverter and the output of the first trigger, the third trigger, the other: whose input is connected to the second output of the clock, and the output is the output of the device and is connected to the other input of the second OR element , the other inputs of the first element I are connected respectively to the first and second outputs of the clock, the output of the input pulse shaper is connected to another input of the first trigger, the other inputs The second element And are connected, respectively, 4J with the outputs of the second trigger and the primary 4th inverter.

Description

 1 11

The invention relates to communication technology and can be used in the reception of pulse signals in synchronic communication systems under the conditions of exposure to intense pulse interference.

A device for protection against impulse noise is known, containing a receiving trigger whose outputs are connected to the inputs of a registering trigger through corresponding elements AND, and a prohibition signal generating unit through an OR element connected to control inputs of the elements of IC1.

However, this device does not provide effective protection against impulse noise packets, which at certain time ratios can be taken as signal pulses.

The closest in technical essence to the invention is a device for protection against impulse signals, catching, containing input shaped pulses, a clock generator, and connected first sequence OR element, first trigger and first element, AND In addition, the known device contains a pulse counter, the input of which connected to the output of the clock pulse generator 123.

However, due to the sensitivity of the known device to the first impulse noise in the allowed interval, it clearly has an insufficient noise immunity.

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

The goal is achieved by the fact that the device for protection against impulse noise when simultaneously receiving pulsed signals, contains an input pulse shaper, a clock pulse generator and the first OR element connected in series, the first trigger and the first AND element, the first inverter is inputted, the input and output of which are connected respectively, with the first output of the clock generator and the first input of the first element OR, connected in series by the second inverter:: the hopper of which is connected to the second output of the generator and clock pulses, the second element AND, the output of which is connected to the second platoon of the first element OR, the second element OR, second 78412

a swarm trigger, the other input of which is connected to the output of the first element I, the third element I, the other inputs of which are connected respectively to the 5th first output of the clock, the output of the second inverter and the output of the first trigger, tre-. the third trigger, another input of which is connected to the second output of the clock, and output from the device and connected to another input of the second OR, other inputs of the first And | | Is connected respectively to the first and second outputs of the clock, the output pulse shaper connected to another input of the first trigger, the other inputs of the second element And are connected respectively to the outputs of the second trigger; and the first inverter. .

FIG. Figure 1 shows the structural electrical circuit of the proposed device; in fig. 2 - voltage diagrams for his work.

The device for protection against impulse noise with synchronous pulse signals contains an input driver 1 pulses, a communication line 2, the first trigger 3, a generator of 4 clock pulses, the first inverter 5, the first element OR 6, the first element And 7, the third element And 8, the second 9 and the third 10 triggers, the second element OR 11, the second element And 12, the second inverter 13.

The device works as follows.

The input of the pulse generator 1, which may be, for example, an integral part of the transmitter of the pulse signals of the synchronous communication system, receives binary pulses that can occupy certain discrete allowed positions on the time axis. FIG. 2a is a time chart of allowed pulse positions, and FIG. 26 - one of the transmitted pulses.

By the input driver 1, the transmitted pulses are amplified to the required level and are differentiated in such a way as to obtain the minimum, determined by the parameters of the link 2, the duration of the differentials. The polarity of the pulses is chosen such that the polarity of the front-front differential is as far as possible opposite the polarity of the most frequent impulse noise encountered in a given communication line. Differentiated pulse signals (Fig. 2c) through line 2 are fed to the input of the first trigger 3, which is in the initial state of waiting for polarity pulses, corresponding to the polarities of the leading edges of the transmitted pulse signals. The trigger threshold of the first trigger 3 is selected so that it does not react to low level interference, but at the same time J, to ensure reliable reception of useful signals. FIG. 2d shows the time diagram of the signal at the input of the first trigger 3 (differentials I1 and I2), which acts against the background of a different kind of pulsed interference SP1, n2j; .., P5). The generator of 4 clock pulses receives two pulse sequences: the first sequence f, which repeats the sequence of allowed pulse positions (Fig. 2a), and the second f with the same frequency, but each pulse contains two pulses that cross the possible reception intervals of the front differentials and trailing edges (Fig. 2d). Obviously, in the particular case when the sequence f is a meander. The sequence fj through the first inverter 5 and the first element OR 6 is fed to the setup input of the first trigger 3, allowing it to work only during the expected arrival of the differential of the useful signal. Consider the operation of the device when receiving a useful signal. The differential front of the H1 pulse (Fig. 2d) enters the input of the first trigger 3 at the allowed time and starts it (Fig. 2e). From the paraphase outputs of the first trigger 3, the low level enters the input of the third element And 8, and the high level goes to the other input of the first element And 7, Since at the moment of receiving the differential of the leading edge of the useful signal, the first element And 7 is also open at the two other inputs, then it opens, and the second trigger 9 starts, opening the third element AND 8 at the second entrance (phage. 2g). In this state, the device remains until the arrival of the differential front edge of the useful signal. When the trailing edge arrives (pulse I2 in Fig. 2d), the first trigger 3 returns to its initial state, a high level from it arrives at the third element And 8, on the remaining inputs of which a high level also acts at this time. The third element And 8 opens, launching the third trigger 10 (Fig. 2h). High level, the output of the third trigger 10 through the second element OR 11 resets the second trigger 9 to the initial state. The third trigger 10 in this case fixes the reception of the next pulse and returns to its initial state with the front of the beginning of the next period of the sequence f. The device is ready to receive the next pulse. Upon receipt of impulse noise, the proposed device responds to them differently, depending on their polarity and temporal position relative to the pulse sequences f and f 2. Consider various cases of interference. While waiting for the leading edge of the useful signal, the first trigger 3 does not perceive interference, the polarity of which is opposite to the polarity of the expected differential (pulse P1 in Fig. 2d). No interference is also perceived, the polarity of which coincides with that expected, but which act outside the resolution pulses of the sequence fj (pulse P2 in Fig. 2d). When interference is received, the polarity of which coincides with the polarity expected by the first trigger 3 and acting in the time interval allowed by the sequence fj (pulse PZ in Fig. 2d), the Baet trigger device is the same as when receiving the I1 pulse. In the absence of a pulse of opposite polarity, the first trigger 3 does not return to its original state at the appropriate time, the third element 8 remains closed, the third trigger 10 does not start. Upon termination of the impulse $ 111

ca of enabling the reception of the differential front (sequence fj) opens the second element AND 12, which, through the first Element OR 6, resets the first trigger 3 and, via the second element OR 11, the second trigger 9.

Thus, the proposed device for protection against interference in sync841

NIC communication systems provide almost complete detuning from impulse noise {of various types, passing them to the device only in the 5 low probability combination of polarity and location on the time axis when they do not differ from the location of the expected signal differentials of the device.

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Claims (3)

DEVICE. PROTECTION AGAINST PULSE INTERFERENCE WITH SYNCHRONOUS RECEPTION OF PULSE SIGNALS, containing an input pulse shaper, a clock generator and connected in series the first element OR, the first trigger and the first element AND, characterized in that, in order to increase the noise immunity, c. it introduced the first inverter, the input and output of which are connected respectively with the first output of the clock.pulse generator and the first input of the first OR element, 4 · * connected in series to a second inverter, the input of which is connected to the second output of the clock generator, the second AND element, the output of which is connected to the second input of the first OR element, the second OR element, the second trigger, the other input of which is connected to the output of the first AND element, the third element And, the other inputs of which are connected respectively to the first output of the clock generator, the output of the second inverter and the output of the first trigger, the third trigger, the other input of which is connected to the second output of the clock generator output pulses, and the output is the output of the device and connected to another input of the second OR element, other inputs of the first AND element are connected respectively to the first and second outputs of the clock generator, the output of the input pulse former is connected to another input of the first trigger, other inputs of the second element And connected respectively to the outputs of the second trigger and the first inverter ... ".SUo., 1117841 7841 2 swarm trigger, the other input of which is connected to the output of the first element And, the third element And, the other inputs of which are connected respectively to 5 by the first output of the clock generator, the output of the second inverter and the output of the first trigger, the third trigger, the other input of which is connected to the second output of the clock generator 10, and the code is the device code and connected to the other input of the second OR element, the other inputs of the first AND element ( Connected respectively with the first and 15 second inputs of the clock generator, the output of the input pulse former is connected to another input of the first trigger, the other inputs of the second element And are connected respectively vkodami second flip-flop and the first inverter.. In FIG. 1 shows a structural electrical diagram of the proposed device; in FIG. 2 - stress diagrams explaining its operation. The device for protection from impulse noise during synchronous reception of impulse signals contains an input driver 1 pulses, a communication line 2, a first trigger 3, a clock generator 4, a first inverter 5, a first element OR 6, a first element And 7, a third element And 8, the second 9 and the third 10 triggers, the second element OR 11, the second element And 12, the second inverter 13. The device operates as follows. At the input of the input pulse shaper 1, which can be, for example, an integral part of the pulsed signal transmitter of a synchronous communication system, binary pulses are received, which can occupy certain discrete allowed positions on the time axis. In FIG. 2a is a timing chart of the allowed pulse positions, and FIG. 26 is one of the transmitted pulses. The input shaper 1 transmitted pulses are amplified to the required level and differentiated in such a way as to obtain the minimum, determined by the parameters of the communication line 2, the duration of the differentials. The pulse polarity is chosen so that the polarity of