SU481139A1 - Duplex telegraph communication method by multi-frequency code - Google Patents

Description

one

The method can be applied to existing radio channels and telegraph channels. There is a method of duplex telegraph communication with a multi-frequency code, in which the transmitted code combination of each character is converted into the corresponding sound frequency, and the received signal is demodulated, and the amplitude of received signals are compared with a set threshold level . The disadvantages of this method are relatively low channel capacity, accuracy and reliability of receiving information in conditions of increased interference due to the fact that there is no automatic detection and correction of errors in the received information.

The purpose of the invention is to increase the noise immunity of the communication. This is achieved in that by the described method, by means of the generated pulse, the reception of the next, following the distorted sign n is simultaneously interrupted by transmitting the second half of the sign and after half the transmission duration of the interrupted sign, the transmission of the preceding and interrupted signs is repeated. In addition, when blocking distort this sign on the side of the correspondent, block

receiving by the correspondent a sign that precedes the distorted one, and accepts the following and repeated on its own transmission and repeated siac, and simultaneously blocks the transmission of the second half of the correspondent sign, and on each side of the communication line the transmitted signals shift in time relative to the received signal .

On fng. 1 shows signal diagrams illustrating the essence of the proposed method; in fig. 2 shows a structural block diagram of a device that implements the proposed method.

The essence of the proposed method is as follows.

The signal, for example, B from station 1, of the correspondent is transmitted to station 2 (hereinafter referred to as its own). Simultaneously with a shift in time by half the duration of this signal (G / 2), a transmission occurs, for example, the sign K. from its own} station. In the process of transmission, each information sign is converted into start, five code and stop pulses (seven-digit code a), five code pulses are stored, the converted code combos are transferred from variable speed T to a constant uniform speed TZ transmission using clock pulses ( b) and code

the combination of each character is converted to the corresponding sound frequency (c).

On the receiving side, the audio frequency signal (d) is amplified and limited but amnltudude (d), the frequency of each character is distinguished (e), detected (g), reconstructed with the help of this signal, or ultrasonic signal (s) which is converted into a five-digit code, service HBie — starting and ston — is added to it — pulses and the entire combination of nm pulses is converted into an information sign (k).

In the event of the occurrence of a non-fault at the time of non-transmission, for example, the signal B, the adopted frequency (l) is distorted. In this case, the amplification and limitation of the signal detects a distorted shape (m), and after entering the frequency has the appearance of an irregular cone (n). After detection, this signal takes the form of a distorted sawtooth signal (o). As a result, a narrow pulse (ha) will decrease but amplitude. Since the pulses are constantly correlated with the formed summation of interference and the output of the selection elements by the level (p), when an interference occurs, a decrease in the level of a narrow emulsion (l) to or below the formed level (p) creates an impulse (c) by which reception next signal, for example. G, following; its distorted sigial B, and at the same time the transmission of half of the code combination of the currently transmitted sign / C is interrupted at station 2 BTOpoii. Through a time interval equal to half the period (G2 / 2) of the transmission of the interrupted sign K, the transmission of And and pre-A / C signs. In this case, the transmission of the second half of the code combination of the transmitted sign K is blocked, which distorts the reception of this sign at station 1 and blocks the reception of station I sign preceding the distorted sign K at station I, and the interrupted sign K following it is received. At the same time, the second station 1 half of the code combination of the transmitted G character, as a result of which, when the end of the blocking occurs, the transmission of zpacks into and G.

When the level of the received signal from station 2 drops below the threshold level p, all operations for blocking and repeating code combinations of transmitted and received characters are performed in a similar way.

In the absence of transmission of text, unomu nick 1e operations are performed with synchronization signals.

The proposed method can be implemented using the device shown in FIG. 2

The transmitter 3 converts the perforated code on the tape into electrical signals of the five-digit code. The electrical signals from the transmitter are fed to the input of the transmitting apparatus, operating with a multi-hour code, where with the electronic start- on rsflegeltel 4 code parcels are assigned; 5; Rasplat, elitsl 4; th time stonozoy and paryl gives two pulses pas throwing

Blo G, which, having operated from the first impulse, pYiK t at the same time, all cells of the drive 5 1; mp L1chY d.ch ns) ebros) 1x ;; new packages from the drive 5 ia) 1 accumulator 7. toll: 7 is transferred to the accumulator 8 using the drawing of the other unit 9. The storage unit 8 controls the selection switch 10, which outputs the sound frequency to the line (see Fig. 1, c) in accordance with the transmitted sign of the third-party code.

P1a, to the receiving device, an audio frequency signal (see Fig. 1, d) is amplified from the line and limited in amplitude by the AND block and fed simultaneously to the inputs of the tuners to

corresponding frequencies): elements 12. The voltage amplitude on the element, the tuning frequency of which coincides with the frequency of the received signal, increases linearly (see Fig. 1, s). Therefore, by the time of

a clock pulse (see FIG. 1, h), the signal after detection takes a saw-tooth shape (see FIG. 1,). From elements 12, the sawtooth signals of the multi-frequency code are fed to block 13, where they are converted into

narrow pulses (cf. fig. 1, n), which are compared in terms of level with a set threshold level (see fng. 1, p). Next, the narrow pulses are converted by the code converter 14 into the parcels of the five-digit code, to which the service ones are added - the starting and table parcels. The entire seven-digit combination of parcels (see Fig. 1, k) is transmitted to the direct printing apparatus 15 with a nominal electronic start-stop distributor.

The memory device 16 memorizes two last signs with 8 n accumulators to repeat them in case of a distorted received sign (with a narrow pulse below the threshold level) on block 13. In this c; (block 17 creates an emulsion (see Fig .,), providing the necessary blocking of reception, transmission l repetition of distorted characters.

P r cd m from invention

A duplex telegraph communication method of multiple (1CH) frequencies1 by a code in which the transmitted code combination is converted

sign to the corresponding sound frequency, and the received Opal is demodulated, and the signal amplitudes are compared to: .uu: vb signals with an increased threshold level and npii decrease in the signal signal

and below the local level, the gates are formed by a strobe, their impulse, distinguished by 1: 1; c: tag, which, s, 1 increase the robustness); communication, by means of a generated pulse, block the reception of the queue, next to the distorted sign, and simultaneously interrupt the transmission of the second half of the sign and after half the transmission duration of the interrupted sign repeat the transmission of the preceding and interrupted characters; the reception by the correspondent of the sign that preceded the distorted one, and the interrupted and repeated mark, which was interrupted after it on his own transmission, and also blocked the transmission of the second half of the sign transmitted by the correspondent, and on each side of the communication line the transmitted signals are shifted in time relative to the characters received by half the duration.

Reiteration