SU1580581A1 - System for transmission of binary information - Google Patents

Abstract

The invention relates to communication technology and can be used in the construction of discrete information transmission systems by orthogonal Walsh signals with time division channels along cable lines. The system comprises on the transmitting side a Walsh signal generator, N signal converters and an adder. In order to increase noise immunity at a given peak power of the group signal, a serially connected binary counter and a shaper of the levels are introduced on the transmitting side. 2 Il.

Description

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There are 5 levels, and on the receiving side a low-pass filter 7, a comparator 8, a Walsh signal generator 9, signal converters 10 and reversible binary counters 11. Introduction of a binary adder 3 and a driver 5 on the transmitting side and a filter 7 and a comparator 25

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The invention relates to communication technology and can be used in the construction of discrete information transmission systems by orthogonal Walsh signals with time division channels along cable lines.

The purpose of the invention is to improve the noise immunity at a given peak power of the group signal.

FIG. 1 shows a structural electrical transmission system diagram; in fig. 2 - time diagrams that show his work.

The transmission system contains on the transmitting side Walsh signal generator 1, signal converters 2, binary adder 3, binary counter 4, a shaper of 5 levels, the transmitting and receiving parts of the system are connected by a cable connection line 6, and on the receiving side a low pass filter 7, a comparator 8, Walsh signal generator 9, signal converters 10, reversible binary counters 11.

The transmission of binary information works as follows (the operation of the transmission system is considered on the example of the use of 16 Walsh functions).

The synchronization device of the transmitting part of the system generates pulse sequences Takt1, Record, Counting (Fig. 2). Under the action of the Tact 1 sequence, the Walsh signal generator 1 produces periodic (with a period T) signals that are inverted logical equivalents of the Walsh functions. In a logical equivalent

40

the Walsh function to the logical O corresponds to the value of the function, the Walsh value equal to minus 1, and the logical 1 value corresponds to the value of the Walsh function equal to 1. In FIG. 2 shows time diagrams of the 1st, 2nd, and 16th Walsh signals (Ex.

The torus 8 on the receiving side allows to increase the noise immunity. In addition, the group signal in the proposed system has a two-level character t, which simplifies its formation and processing, as well as regeneration during transmission over long distances. 2 Il.

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1.1 Exit 1.2, Ex. 1.16) ,. corresponding Walsh functions numbered 0,1,15. The outputs 1,2 and 16 of the transducers 2 receive binary information that must be transmitted. This information arrives at times equal to O, T, 2T, etc., and remains unchanged for time T, while information is being transmitted. FIG. 2 shows time diagrams of signals at inputs 1, 2, and 16 of transducers 2 (In. 2.1, In. 2.2, In. 2.16) when the binary information is received at them at time t О About 0.1.0, and at time t T - Information 1.0.1, respectively. At the outputs of converters 2, we have logical equivalents of Walsh functions or inverted logical equivalents of Walsh functions depending on the transmitted information — JUHH (1 or 0) at inputs 1,2 and 16. At the outputs of one-digit binary numbers, the binary code forms the sum of logical units per his inputs. This code is recorded at the beginning of each interval t T / 1 6 into a binary counter 4 pulse Record, and then at each interval C the counter clock input receives 15 pulses Count, which follow with an interval of 1, while at interval T at the output of the higher bit counter 4, an output signal is generated. 4, a timing diagram of which is shown in FIG. 2 in the interval from 0 to 2 for the case if the counter at time t 0 was recorded from the outputs of the adder 3 code 01101 (13 units at the inputs of the adder), and at time t, the code 00101 (5 units at the inputs of the adder). At the output of the shaper 5 levels, a two-level signal S (t) with a given power A is generated from the signal Ex.4.

Thus, in the interval from O to T, a group signal is formed.

), corresponding to some information unchanged during this interval at the inputs 1,2, .., 16 converters 2. If t1, mark the duration of the negative part of the signal S (t) on a not V-interval; and through Ј2 - the duration of the positive part of S (t)

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Where

n 0, ± 2, ± 4 ,, ± 6, .... It can be said that n-is the difference between the number of intervals / 00, corresponding to the positive part of the signal S (t) on some interval 1, and the number of intervals

y, corresponding to the negative part of the signal S (t) on the same interval.

On cable line 6, the signal S (t) is subject to interference. In the low-pass filter 7, the frequency band of the signal coming from the communication line is limited by the cut-off frequency of the filter. Comparator 8 generates a signal of logical 1 or logical O, whichever is greater.

or less zero signal arriving at its input from the output 7 of the lower frequencies. I The synchronization device of the receiving part of the transmission system produces periodic pulse sequences Tact 2, Reset, Strobe} whose time diagrams are shown in FIG. 2. The sequence Tact 2 has a period D and must be synchronized with the moments of zero crossing of the negative edges of the useful signal at the output of the low-pass filter. The Reset sequence has a period T and must be synchronized with the beginning of the information signal at the output of the low-pass filter 7. The Strobe sequence has a period “and must be synchronized with the sequence of Tact 2 so that the pulses of the sequence of Tact 2 coincide with the middle of the intervals between the pulses of the Strb sequence, - Walsh signal generator 9 and converters 10 work similarly to Walsh signal generator 1 Reversible binary counters 11 function in such a way that when there is an input on the selection of the signal mode of the corresponding logical 1 or 0

logical U, the state of each counter 11 with the arrival of each pulse The strobe increases or decreases by one. Impulse Reset

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all reversible counters 11 are set to the zero state before starting the processing of the group signal. The state of the bits of the reversible counter 11 correspond to the 8-bit additional code of the difference between the number of Strobe pulses passed to the counter input in the summation mode and the number of Strobe pulses passed to the input of the counter 11 in the subtraction mode, if during the counter operation no overflow occurred. The high bit of the reversing counter 11 indicates the sign of this difference: if the high bit is in the state

0, then the sign is positive, but if the most significant bit is in the state

1, then the sign is negative.

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On each interval With reversive

counter 11 can change its state by n or n depending on which value 0 or 1 is received by the Walsh signal at the input of the corresponding converter 10. If at the end of the group signal processing interval T the sign (most significant) bit of the reversing counter 11 is set to state 0, then 1 is transmitted through the corresponding channel, and if the sign bit is set to state 1, then 0 is transmitted through the channel. Thus, to determine 1 or 0 transmitted through this channel, it is necessary to read the value of the upper shaft T and

Invert this value.

Claims (1)

Invention Formula 0 e The binary transmission system, which contains the Walsh signal generator, n signal converters and the adder, the first inputs of each of the signal converters are the information inputs of the system, the Walsh 5 signal generator outputs are connected to the second inputs of the corresponding signal converters, the outputs of which are connected to corresponding inputs of the adder, and at the receiving side - n signal converters and a Walsh signal generator, whose outputs are connected to the first inputs of the corresponding their transducers, the second inputs of which are connected, characterized in that, in order to increase the noise immunity at a given peak power of the group signal, serially connected binary counters are introduced on the transmitting side A tick and a shaper, the output of which is the Output of the transmitting part of the system, and the adder is made in the form of a binary adder, the outputs of which are connected to the corresponding inputs of the binary counter, the Record and Counting inputs of which are the names of the transmitting part of the system - series-connected low-pass filter and comparator, as well as n reverse binary Record EXIT 11 8x { 8x22 H.2.15 Exit f The counters whose outputs are information outputs of the system, the input of the low-pass filter is the input of the receiving part of the system, the output of the comparator is connected to the combined second inputs of signal converters whose outputs are connected to the mode selection inputs of the corresponding reversible binary counters whose clock and setup inputs are The inputs are Strobe and Reset, respectively. m