SU1496013A2 - Device for correcting of dominance-type distortions - Google Patents

Abstract

The invention relates to communication technology. The purpose of the invention is to increase the speed by adjusting the magnitude of the predominance both in zero message elements and in individual elements and their groups, accuracy and noise immunity due to the response to the location of each front of the group signal. The device contains a comparison unit 1, a single pulse extraction unit 2, a standby generator 3 reference pulses, a synchronization unit (BS) 4, a control signal generator 6 that drives the generator 7. BS 5, trigger 8 is entered into the device , the element is NOT 9, the element is AND-NOT 10, the element OR 11 and the element And 12. 4 Il.

Description

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The invention relates to communication technology, can be used in the receiving part of the equipment for transmitting discrete messages to eliminate the predominance in the received elements of the message and is an improvement of the invention according to the author. № 1 113899.

The purpose of the invention is to increase the speed by adjusting the magnitude of the pre-charge both in terms of zero elements and in terms of single elements and their groups, accuracy and noise immunity due to the response to the location of each front of the group signal.

FIG. 1 shows the structural electrical circuit of the proposed device; in fig. 2 is a comparison block diagram; in fig. 3 is a diagram of a single pulse extraction unit; FIG. 4 is a diagram of a waiting generator of reference pulses.

The device contains a comparison unit 1, a single pulse 2-unit, a generator 3 reference pulses for the WAIT, 3 synchronization blocks 4 and 5, a control signal generator 6, a master oscillator 7, trigger 8, HE elements 9 ,. AND-NOT 10, OR 11 and AND 12 o Block 1 consists of (elements AND 13 and 14 and OR 15. Block

2Sign, from the differentiating unit 16, the element OR 17, the elements And 18 and 19 and the trigger 20. The waiting generator

3 consists of a differentiating unit 21, elements AND 22-27, triggers 28-31 and element OR 32.

The device works as follows 1m.

The received message elements from the output of the threshold element (not shown) J that corrects the ratio of the length of the single and zero elements of the message between each other, are sent to the input bus of the device and then the second inputs of the comparison generator 1 of the standby generator 3 reference pulses, synchronization unit 4 HE and element 9. At the same time, from the output of master oscillator 7, a sequence of high-frequency pulses is fed to the first inputs of synchronization blocks 4 and 5. Block

4 realizes the adjustment of the frequency and phase of the clock pulses generated by it to the frequency and phase of the received message elements, as a result of which

four

The following clock pulse sequences are formed at its outputs: and the third output is a sequence of pulses arriving from the telegraphing frequency and coinciding in phase with the falling edge of the received message elements; at the second output, a sequence of high-frequency pulses are formed so that regardless of the instability of the wiring speed and the frequency instability of the master oscillator 7, only the same number of high-frequency pulses are received for the duration of one undistorted single element of the message; at the fourth and first outputs - the pulse sequence is similar to those formed at the third output of block 4 | but spaced farther from them, respectively, to the left and to the right by the amount of C, the maximum possible change in the duration of a single message element due to the predominance. . At the same time, the input elements of the message arrive at the input of the HE element 9, from the output of which the inverted sequence of received message elements enters the second inputs of the synchronization unit 5 and the NAND element 10. Thus, the use of the HE element 9 provides conversion front (rear) edges of the elements of the input messages to the rear (front) edges. As a result, block 5 synchronization, similarly to block 4, performs adjustment of the frequency and phase of the clock pulses generated by it to the frequency and phase of the received elements co. communication, as a result of which the following clock pulse sequences are formed at its outputs: at the second output, a sequence of pulses that follow the wiring frequency and coincide in phase with the leading edge of the received message elements; in the first and third outputs, there are sequences of pulses similar to those formed on the second output of synchronization unit 5, but spaced respectively from them to the right and left by an amount n of the maximum possible change in the duration of a single message element due to prevalence.

Thus, blocks 4 and 5 of synchronization in the process of formation are 1D9601

Voltage impulses take into account the instability of the speed of wiring, the instability of the work of the master oscillator 7 and monitor the phase of the back and front edges of the received elements, respectively.

 The clock pulses generated at the third and fourth outputs of block 4 are received respectively at the fourth and fifth inputs of the waiting generator 3, the clock pulses generated at the first output of block 4 are fed to the first inputs of the waiting generator 3) 3 and element OR 11.

In the event of a breakdown in operation (for example, a failure in the transmitter or channel of the generator apparatus), as well as when receiving a message element with a randomly distorted falling edge, the pulse at the third output of block 4 does not coincide in time with the falling edge of the received 25 message element , as a result, the launch of the standby generator 3 does not occur, which increases the noise immunity of the device. When a clock pulse coincides at the third AO output of block 4 with the falling edge of the received element (or group of elements) of a message, a pulse is formed at the second output of the standby generator, which prepares a single pulse extraction unit 2 for operation, and at the first output of the standby generator 3 under the influence of clock pulses arriving at its fifth and first inputs, a signal is generated up to a reference duration (1. Comparison unit 1 compares the duration and phase of a reference pulse of duration 2 with the forward fr phase The nta single unit (or their group) of the received message elements, i.e., actually with the duration of the zero element (or their group) preceding the measurement process. As a result of the phase comparison of the pulses, a pulse is generated at the output of the comparison unit 1, the duration of which haakertizes the magnitude and sign of the predominance of the received elements of the message. 55. In the case of the absence of dominance, the duration of the pulse, at the output of lock 1, is

t 2 g- „- g: tf ,.

35

five

0 5 o o 5

five

36

Simultaneously with the operation of unit 4, synchronization unit 5 generates, at the third and second outputs, clock pulses, respectively, arriving at the eighth and seventh inputs of the standby generator 3. Clock pulses, formed at the first output of block 5, arrive at the sixth input of the ear generator 3 and to the second input of the element OR 11. In case of violation of the common mode of operation, the pulse at the second output of block 5 does not coincide in time with the leading edge of the received element of the message. As a consequence, the start of the waiting generator does not occur.

When a clock pulse coincides at the second output of the block with the front of the received element of the message in front of it, a pulse is generated at the second output of the waiting generator 3, which presses the single pulse extraction unit 2 to work, and at the third output of the waiting generator 3 under the influence of the clock pulses its sixth and eighth inputs form a signal of a reference duration, which is fed to the first input of the I-PE element 10 and to the third input of the comparison unit 1. The element AND-NE 10 compares the duration and phase of the reference pulse with the phase of the leading edge of a single element of the message (trailing edge of the element of the input message), i.e. in fact, the duration of the zero element of the message preceding the measurement process, as well as the inverse of the received overlap signal. The generated signal from the output of the NAND unit is repeatedly compared in block 1 of the comparison with the C1 signal of the reference duration 2 t arriving at the third input of the block 1, which ensures the pulse formation at the output of the block 1, the duration of which characterizes the magnitude and sign of the prevalence of received message elements (in the absence of dominance, its duration is). The use of the element AND-NE 10 provides protection against the formation, or at the output of block 1, of comparing false pulses of duration 2 if there are groups of zero elements in the received message and takes into account the conversion in the NOT element of the current (current) predominance of the input elements of the message to currentless (current) predominance at the input of block 5 synchronization.

The signal with the duration tf from the output of the comparison unit 1 is fed to the first inputs of the control signal generator 6 and the single pulse extraction unit 2, which was prepared for operation by a pulse received at its second input from the second output of the standby generator 3 at the instant of coincidence of the rear or front the front of the received message element with a clock pulse, respectively, at the third output of block 4 or the second output of block 2.

A pulse leading up the formation of 3 pulses of the reference duration 2 t in the subsequent cycles of the device (until a new coincidence in the back or front edge of the received element messages jc clock pulses at the third output of block 4 or the second output of block 5) J but not interrupting the pulse duration 5 already formed by the waiting j generator 3 reference pulses at its first and third outputs in a given cycle p work The formation of a pulse on the second output of the unit 2 is accompanied by the installation of the unit 2 for extracting a single pulse into the initial state. Subsequent arrivals of pulses at the first input of unit 2 (form Jpyemye in the predominant measurement zone, for example, due to crushing of noise, etc.) do not lead to the formation of pulses until the installation of unit 2 in the ready state of the impulse from the second output of the waiting generator 3-.

The impulse coming in at the second input of the former 6 clears its counter to zero, i.e. prepares the former 6 for a new cycle of operation. The duration of the signal at the fourth input of the Formative 6 determines the number of high-frequency clock pulses coming from the second output of the synchronization unit 4 to the clock input of the counter of forms 1p6tel 6. Thus, the code of the number recorded in the counter characterizes the duration of the output of the comparator 1 output

consequently, the magnitude and sign of the predominance of received message elements. Before entering the meter readings into the transducer, the generator 6 is checked for the accuracy of the measurement results. Its weakness (the notification is provided by the use of the trigger 8, the elements OR 11. And AND 12, the corresponding implementation of the allocation unit 2, the living generator 3, and the presence of corresponding connections.

Verification is carried out with the following.

If the standby generator 3 reference pulses are started at the back edge of the input signal, then the front edge of the next measurement of the email message with the pulse at the second output of the block 5 is checked, and if the start is performed at the leading edge, then the match is checked trailing edge with a pulse at the third output of block 4. In these cases, a pulse is formed at the third output of block 2, which sets trigger 8 into a single state and allows passage through element 12 (with output element OR 11) of the signal from the first output of block 4 or the signal from the first output of block 5.

At the moment the generator 6 arrives at the third input, a pulse from the output and the meter reading element are inserted into the converter voltage-voltage generator 6, which results in the corresponding level of corrective voltage prevalence on the sensor 6, which results in the threshold block resulting from This is a change in the ratio of the time lengths of the unit and zero elements of the message on the input bus of the device.

If there are no dominances in the received message elements, the duration of the signal at the output of comparison unit 1 remains unchanged and equal to tff from one operation cycle of the device to another, the same number of pulses is always recorded in the counter, and ONE is entered into the code-voltage converter of the former 6. and the same meter readings, resulting in a constant

the level of corrective prevailing voltage at the output of the device. In the case of current prevalence of t in the communication channel, i.e. when the duration of a single message element exceeds the nominal duration of the undistorted element, the communication, the duration of the signal at the output of comparison unit 1 is (The value

. t 2 f "- () tf. + t.

Where

 t is the duration of current prevalence.

As a result, the clock pulse on the V code of the driver 6 of the control signal forms the corresponding level d, + G of the level of the correction prevailing voltage, which is higher than the nominal voltage level at the output of the device.

In the case of currentless prevalences of t at the output of comparison unit 1, a pulse of duration is formed

t 2. (e “-c) G“ -T,

where, at output 1 |) of the adjuster 6, a level of corrective voltage predominance is formed which is lower than the nominal voltage level at the output of the device.

Claims (1)

Formula invented and A device for compensating for distortions of the type of predominance according to the author. ten 15 0 five P 0 five No. 1113899, characterized in that, in order to improve speed by adjusting the magnitude of the prevalence of both zero message elements and single elements and their groups, accuracy and noise immunity due to the response to the location of each front of the group signal, a second synchronization unit is introduced, the trigger and the elements NOT, AND-NOT and OR, the first output of the first synchronization unit is connected to the third input of the control signal generator via the serially connected element OR and element AND, first and volts The swarm outputs of the single pulse pulse unit are combined, and the third output is connected to the first trigger input, the output of which is connected to the second input of the AND element, the output of which is connected to the second trigger input, the second input of the OR element is connected to the sixth input of the waiting generator of the reference pulses and the first output of the second synchronization unit whose first input is connected to the output of the master oscillator, and the second and third outputs are connected respectively to the seventh and eighth inputs, waiting for the reference pulse generator, the third the output of which is connected to the first input of the NAND element and the third input of the comparison unit, the fourth input of which is connected to the output of the NAND element, the second input of which is connected to the second input of the second synchronization unit and the output of the NOT element whose input is connected to the input of the device. Phi2.2