SU1427595A1 - Device for detecting signals of multiposition frequency telegraphy - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to simplify the device by eliminating a number of blocks. The device contains in the channels bandpass filters 1, 2 and 3, blocks of auto selection (BAB) 4.5 and 6 voltages, blocks 7.8 and 9 of level control, amplitude. detectors 10, 11 and 12, as well as comparison unit 13; In the presence of a signal in any of the channels, the noise components are suppressed by signal voltage through feedback circuits, which are formed by connecting the output of each channel to the inputs of the other active substances , 2 Il.

Description

The invention relates to radio engineering and can be used in information transmission systems.

The purpose of the invention is to simplify the device by eliminating a number of blocks. Fig. 1 shows a structural electrical circuit of the device in Fig. 2, diagrams explaining its operation.

The device contains band-pass filters 1, 2 and 3, blocks 4.5 and 6 of auto voltage selection, blocks 7, 8 and 9 of level control, amplitude detectors 10, 11 and 12, block 13 comparisons.

The device works as follows.

; Each of blocks 7.8 and 9 decreases the transmission coefficient by increasing the voltage at the control input, and when the control voltage equals zero, the controller's transfer coefficient is equal to one, and when the control voltage is greater than K input (K - feedback loop transfer coefficient, defined by the expression K uUpgr MUnnp, where uUnnp is the voltage change at the control input of the bHv regulator bUper caused by this change of the voltage at the regulator's output at a constant voltage at its output) block 7.8 and 9 completely locks re uliruemuyu branch.

The operation of the device is illustrated by the oscillograms of the processes shown in FIG. 2, where the following symbols are taken:

and

 bh;

and

R:

and

Bbix;

the envelope of the signal in the i-ro bandpass filter signal at the control input of the 1st level control unit;

signal at the output of the i-ro amplitude detector. As can be seen from a review of the processes, in Fig. 2a, b, the signal is transmitted at the tuning frequency of bandpass filter 1 at time intervals tijt, from the frequency, adjusting bandpass filter 2 at the time interval LO-, t, at the tuning frequency of bandpass filter 3 - in the interval In the time interval 0, t, the signal is transmitted at the tuning frequency of the bandpass filter 2, therefore, the voltage at the control inputs of blocks 7 and 9 is determined mainly

0

five

0

five

0

five

0

five

0

five

output voltage of the second channel (Fig. 2d, e). Fig. 2d, d, e, with a molded line, shows the control voltage, and thin - voltage at the inputs of the auto selection device, i.e. The diagrams illustrate the process of forming the control voltage.

As a result, noise voltages at the outputs of the first and third channels are significantly suppressed (Figure 2G, I), but not in the second channel (Figure 2Z). The voltage at the control input of block 7 is determined by the maximum of the output voltages of the first and third channels (Fig 2d) and has a small value, i.e. suppression of the signaling process occurs to a small extent.

The device works similarly when there is a signal in any of the channels. .

Thus, the noise components are suppressed by the voltage of the signal through the feedback circuits formed by connecting the output of each channel to the inputs of the auto selection devices of the remaining R-1 channels.

The inertia of re-locking processes in cross-feedback loops leads to the weakening of short pulsations and impulse noise in noise channels, which decreases the probability of erroneous reception.

As the analysis showed, the K value should be set in the range of 05414-1.0, depending on the signal-to-noise ratio PC / RSH and on the product of the separation filter band. on the duration of the pulse ufT (degree of uncertainty filters).

Claims (1)

Invention Formula A device for detecting signals of a multi-position frequency telegraphy, containing a comparison unit, and in each channel a series-connected band-pass filter, a level control unit and an amplitude detector, characterized in that, in order to simplify the device by eliminating a series of blocks, an automatic selection unit is introduced into each channel the output of which is connected to the control input of the level control unit, and the inputs of the automatic voltage selection block of each channel are connected to the inputs of the amplitude detectors of the remaining channel ov