SU1741283A1 - Device for receiving bipulse signal - Google Patents

Abstract

Use: communication technology. The device contains 2 differentiating blocks

Description

The invention relates to communication technology and can be used in the construction of discrete information transmission systems.

The purpose of the invention is to increase the reliability of reception by eliminating the propagation of errors while simultaneously detecting two or more errors in a row in a signal.

The drawing shows a structural electrical diagram of the device.

The device contains a first differentiating unit 1, waiting for the multivibrator 2. first and second elements 3 and 4. RS-trigger 5, the first and third elements OR 6 and 7, one-shot 8 with a restart, the second differentiating block

9. second, third and first delay blocks

10, 11 and 12, the fourth and second elements OR 13 and 14.

A device for receiving bi-pulse signal operates as follows.

The input of the differentiating block 1 receives the received bi-pulse signal. At the first output of the differentiating unit 1, positive pulses appear corresponding to the leading edge, and at the second output, to the trailing edge of the received pulses. To isolate the clock signal and information, the bi-pulse signal property is used - the presence of a transition in the middle of the clock interval corresponding to the information symbol is required. Moreover, a positive impulse corresponds to a single symbol after differentiation, and a negative impulse corresponds to a zero. However, when following the symbols of the same name during differentiation, pulses are obtained at the beginning and at the end of the clock intervals. To exclude such non-periodic pulses, a standby multivibrator 2 is used, which is triggered by pulses. corresponding to the middle of the bit interval. The duration of the pulses generated by the standby multivibrator 2 is selected within 0.5T <τ <T, where T is the duration of the clock interval: the period of the standby multivibrator 2.

Using the pulses generated at the inverted output of the multivibrator 2.and using the elements 3 and 4, pulses corresponding to the beginning and end of the bit period are eliminated. As a result of this, pulses corresponding to single signals appear at the output of element m 3, and zero at the output of element And 4. The outputs of these elements are connected, respectively, with the single (S) and zero (R) inputs of trigger 5. At its direct output, binary information is generated from the received bi-pulse signal.

'Using the selection of pulses corresponding to the middle of the bit interval, the output of the OR 6 element forms a sequence of pulses with a repetition period T. If one or more synchronizing impulses are not selected, for example, due to interference to maintain in-phase operation and prevent error propagation, insertion missing clock signals. This insert is provided by a combination of elements OR 7. single-shot 8 with a restart, differentiating block 9, blocks 10 and 11 delay. Until. while the clock pulses appear at the output of the OR 6 element every period, they are. delaying in block 12, the delays for the time Δτ <T / 4 are received at the first input of the OR 13 element and at the same time, through the OR 7 element, at the input of the one-shot 8. By continuously restarting the latter and maintaining the state corresponding to the logical unit at its output.

The period of the one-shot 8 is set equal to (T + Δ g), therefore, if there is no next pulse in the sequence of clock signals at the output of the OR 6 element. then, over time, the one-shot 8 goes to a low state at its output, and the differentiating unit 9 selects a falling front. The insertion of these pulses into the sync sequence is carried out by summing them with the signal. passed from the output of the OR element 6 through the delay unit 12 to the OR element 13. At the same time, the output signal of the differentiating block 9 serves as an error signal and is output to the error signal of the device.

The one-shot 8 is restarted either through the OR element 7 by the next sync pulse at the output of the OR element 6, or by the output signal of the differentiating unit 9 that passed through the delay unit 10. The signal delay is then selected to be (T - Δ t). so that the trigger pulse exactly coincides with the time interval for the appearance of the clock signal. With the selected period of the single vibrator 8 and the delay time in the delay unit 10, the re-appearance of the falling edge at the output of the single vibrator 8 is possible no earlier than after a time interval of 2T.

In this regard, in the absence of a signal at the output of the PLI 6 element for two

1741283 6 or more clocks, it becomes necessary to restore the clock in the intervals between adjacent transitions of the signal at the output of the single-shot 8 to a low state. 5

In this device, this is achieved by supplying the output signal of the differentiating block 9 through the delay block 11 to the second input of the OR element 14. The first input of which is connected with the output of the OR element 10 13.

The delay time in the delay unit 11 is equal to one clock period. As a result, at the output of the OR element 14, a complete sequence of 15 clock pulses is generated, which is fed to the device clock output and is used to restart the standby multivibrator 2.

Claims (1)

The claims 20 A device for receiving a bi-pulse signal containing a first differentiating unit connected in series, the input of which is the input of the device, the first element And and a trigger, the output 25 of which is the output of the device, connected in series to the waiting multivibrator. the second AND element and the first OR element, the second OR element. the output of which is connected to the input of the standby multivibrator and is a sync signal output, and the first delay unit, the second output of the first differentiating unit is connected to the second input of the second element I. the output of which is connected to the second input of the trigger, and the output of the standby multivibrator is connected to the second input the first AND element, the output of which is connected to the second, the input of the first OR element. l and m of h a- ^z e nd o f i with that. in order to increase the reliability of reception by eliminating the propagation of errors while simultaneously detecting two or more errors in a signal, a third OR element, a one-shot With a restart, a second differentiating unit and a second delay unit, the output of which is connected to the first input of the third OR element, are introduced . the fourth OR element, the output of which is connected to the first input of the second OR element, and the third delay unit, the output of which is connected to the second input of the second OR element, the output of the first OR element is connected to the second input of the third OR element and the input of the first delay unit, the output of which is connected to the first input of the fourth OR element, and the output of the second differentiating unit is connected to the input of the third delay unit, with the second input of the fourth OR element and is the device error output.