SU1598197A1 - Shaper of bi-pulse signals - Google Patents

Abstract

The invention relates to communication technology. The purpose of the invention is to increase speed. The device for generating bi-pulse signals contains a shift register 1, r-2, an ELIMINATOR OR 3 element, a counter 4, an OR 5 element, and a pulse shaper 6. The transmitted data from register 1 successively goes to the EL-EXECUTIVE OR 3 e-mail, which also receives synchronizing pulses (CI) from H. 2. As a result, the EXCLUSIVE OR 3 e-mail produces data presented in the bi-pulse code. After the last message symbol has been transmitted, their counting is performed by the counter 4 by CI from r-2. At the output of the counter 4, a single signal appears, according to which the driver 6 generates a single pulse of duration ΔΤ. On the trailing edge of this pulse, the SI sequence formed by Mr. 2 is shifted by Τ by setting the phase of the reference oscillation to the zero state. As a result, the duration of the last character of the message is increased by ΔΤ, which leads to a shift of SI at the receiving side also by the value of ΔΤ. The selection of the moment when the SI location changes by ΔΤ marks the boundaries of the transmitted messages. 3 il.

Description

ate

thirty

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1

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This invention relates to a communication technique and can be used in data overload systems using cola synchronization.

The purpose of the invention is to increase speed.

FIG. Figure 1 shows the structural electrical circuit of the proposed device, - in FIG. 2 - timing diagrams explaining its operation, in FIG. 3 - dependency graphs.

The device contains a shift register 1, a generator 2, an element EXCLUSIVE OR 3. a counter k, an element OR 5 and a driver 6 pulses.

The device works as follows.

The transmitted data from the output of the shift register 1 is successively received at the second input of the EXCLUSIVE 1E OR 3 element, the first input of which receives synchronizing pulses (s) of a square wave type from the inverse output of the generator 2 (FIG. 2a, b). At the output of the EXCLUSIVE 1EE OR OR element The data presented in the bi-pulse code are generated (FIG. 2 d). After the last message symbol (N-ro) has been transmitted, they are counted by the SI counter 4, a single signal appears at its output, according to which the imager 6 generates a single pulse of duration 41 (Fig. 2c). Along the trailing edge of this pulse, the SI sequence generated by generator 2 is shifted by / by setting the phase of the reference oscillation to the zero state (Fig. 2 g). As a result, the duration of the last message symbol increases by jf (Fig. 2 d), , which will lead to a shift of the SI on the receiving side also by the value of l C (Fig. 2e). The selection of the moment of changing the location of the SI by A C marks the boundaries of the transmitted messages.

The pulse, which from the output of the imaging unit 6 arrives at the control input of register 1, is recorded in parallel from the source of the message information. The recording is made from the first to the Nth digit in the time interval C (Fig. 2c), at the zero digit of the de register 1 at this moment in time and the bit of the previous message is found.

The selection of the value of D C is as follows.

five

0

one

974

The devices considered are generatorless, i.e. at the receiving end, the selection of the SR is carried out directly from the received data (differentiation of the fronts of the received parcels takes place), while only the differentiation pulses allocated in the middle of bi-pulse signals are used as the SI (Fig. 2e). As a result of the fact that the received fluctuations of the fronts take place, the value C must be chosen such that a false selection of the shifted SR (false cyclic phasing) does not occur. It is known that the fluctuation of pulse fronts for light guide lines is described by the normal law

H-) P (x) J, e 26 ()

where 6c is the rms error.

In accordance with the fact that for proper separation of a measured SI it is necessary to take into account possible displacements of the SI of the previous cycle (measurement of t is relative to its location), then there will be a composition of normal laws with dispersion

35

6 6, + + 2 6,

(2)

where |) is the SI correlation coefficient

adjacent bits, given that they are not correlated, p O, i, and

i is the standard deviation of SI in (N-1) and N bits, respectively. Given a certain value of the probability of an error occurring during the registration of the SI location, we will determine the value required for its execution

osh

H.

/ 1 l o

f (

6

(3)

in accordance with (3) in FIG. Figure 3 shows the graphs of the Pdc dependence, (d and) for L 0.05T (the most typical case). As can be seen from Figs. 3, to ensure, for example, the values

515981

 10 it is necessary to choose the value of d 0.7T (t is the pulse duration in the bi-pulse signal).

Claims (1)

An apparatus for generating bi-pulse signals, comprising a shift register, a generator and an EXCLUSIVE OR element, characterized in that, in order to improve speed, an OR element, a counter and a pulse shaper are inputted, and the inputs of the shift register are device inputs and the output is connected with the first input element EXCLUSIVE osh 0 five 97 OR, the second input of which is connected to the output of the OR element, the first input of which, the synchronous input of the shift register and the input of the counter are connected to the inverse output of the generator, whose input, the reset input of the counter, the second input of the AND element and the control input of the shift register are connected to the output of the pulse former, the output of which is one of the output of the device, the other output of which is the output of the element EXCLUSIVE OR, the output of the counter is connected to the input of the pulse former. 1 t