SU563935A3 - Receiver - Google Patents

Description

(54) RECEPTION DEVICE

The invention relates to devices for identifying and selecting interference produced by penetrating frequencies in the channel of useful pulses in the receiving part of the interrogation device, which repeatedly produces a regularly tunable frequency band of the response device for identifying the intermittent frequencies of the response device. receives a response signal with a specified number of frequencies for each bit of information and identifies the received information with a distorted code and unequal information, the following another.

A receiving device is known that contains a serially connected converter, an intermediate frequency filter and an amplifier whose output is connected to the useful signal and interference channels, each of which consists of a series-connected bandpass filter, amplifier and pulse generator, the output of which is connected to the useful signal channel : ki to the signal input of the valve circuit, and in the noise channel through an adjustable block of threshold values 1.

A disadvantage of this device is that the comparison of the desired signal and interference is made in amplitude, which is ineffective for protection against interference.

The purpose of the invention is to improve the noise immunity of the device by counting pulses in the interference channel.

For this, the receiver in the noise channel contains a pulse counter, the counting input of which is connected to the output of the pulse shaper in the same channel and through a time relay is connected to its triggering input, and the output through the switch

connected to the control input of the gate circuit.

FIG. I is given a block diagram of the proposed device; pas figs. 2 are diagrams representing electrical signals in various

paragraphs flowcharts.

The principle of operation of the proposed device is based on the transmission of information from a moving device responder to a fixed questioning device. Information consists of twelve bit numbers. For each bit of information, a specific frequency range is provided in the transmission frequency band. Within this frequency range are five frequency sections,

Ava of which are used to denote single-digit digits by the resonant frequencies of the resonant filters placed in the response device. The code is chosen in such a way that always only two of the five possible chests are occupied in the range

hour goth; In this case, the code weight is two. All combinations of this code can be used to denote these numbers. Other combinations of occupancy of frequency sections could arise only due to a change in the code weight. The proposed device contains successively connected converter (mixer) 1, intermediate frequency filter 2 and amplifier 3. The output of the latter is connected to channels 4 and 5, respectively, of the useful signal and interference. Each of them consists of series-connected band-pass filter 6, 7, amplifier 8, 9, and driver 10, 11 pulses. The output of the imaging unit 10 in the channel 4 of the useful signal is connected via a delay element 12 to the signal input of the gate circuit 13. In the noise channel 5 there is a pulse counter 14, the counting input of which is connected to the output of the imaging unit 11 pulses in the same channel and through time relay 15 the quality of which can be used tilting cascade with one stable position, connected to its trigger input, and the output through the switch 16 is connected to the control input of the gate circuit 13.

The operation of the device is as follows.

Time relay 15 with one stable position of Bsegda falls into its pa6o4iee position when a positive part of the pulse is applied at its input. In this case, it gives, through its output, a working sign to the counter 14 pulses of the number, which counts the pulses received from the pulsed driver And so long until the time relay 15 returns to its original position after the time determined by the controlled constant of time. If during this time the positive part of the pulse arrives at its input, it is kept in its working position until the time elapsed, determined by the time constant. An impulse that occurs again at its input during this time extends this time again to a constant time. The number of pulses entering the channel of interference pulses during the time when the operating sign is applied to the counter 14 is determined by the relay 15. Accordingly, the number 14 includes continuously its own, counting from above, the first, second, third, fourth, and so on. potential. Switch 16 can be set after how many counted pulses this locking potential is transmitted further to valve circuit 13. In the proposed circuit, switch 16 has one switching handle with a sliding contact, which is connected to the output contacts counted from above: third, fourth, fifth and m . If the locking potential of the counter 14 is at the third, fourth, fifth, sixth or seventh output contact, then through the sliding

contact and knob switch 16 to get on the locking input of the valve circuit 13.

In the AZ diagram (see Fig. 2), the 5 signals from the amplifier 3 are presented to the parallel channels 4, 5. The L diagram shows the instantaneous signal at the output of the pulse generator 11, where .Vi means the useful signal and SS is the interference signal . In the 10 Lee diagram, uniform rectangular pulses correspond to useful pulses and have a time interval of at least Gd-, and the interference signal 55 becomes irregular along the length of the pulses, the time interval of which is at a maximum of TS. The minimum interval 7 d of the useful pulse at the same time is much larger than the maximum interval TS of the interference pulse. The length of time TSS signal interference depends largely on the difference in the frequency of the transmitted frequency. If the change difference is small, then a long interference signal is generated. If there is a large difference in frequency change, for example, if a constant frequency penetrates from the interference transmitter, the interference signal is relatively short. In the presented example, the duration of the interference signal Tss corresponds to the interference from the transmitter with a constant frequency.

0 When the positive part of the first impulse of the interference signal hits the input of time relay 15, it goes into its operating state and delivers operating potential to counter 14. Since during the time determined by the time constant of the relay 15, shown in diagram L15 as the duration of Ti5, the capital parts of the pulses are applied to the input of the relay 15, it is maintained in the working position until the interference signal dies out. The length of time 7) 5 of the relay 15 which is included in the operating floor box in this case is presented in the Aiy diagram. Counter 15 now counts running pulses of interference continuously and turns on

5 at each pulse of interference, the blocking potential is on its own, counted from above, first, second, third, etc., output. After the third impulse of the interferences, the locking potential falls on its third output and through

0 contact and the knob of the switch 16 - to the locking input of the valve circuit 13. From this point on, channel 4 of the NI useful pulses is locked until the switching potential of the switching input 16 is switched off by switching the relay 15 to its quiet position gate circuit 13. The interference signal 55 is now selected from the NI useful pulse channel. The output signal of gate circuit 13 contains only useful pulses and goes to a digital signal evaluation circuit (not shown).

In order to ensure that the 4 useful pulses .Vi are also selected from channel 4, the first interference signal pulses 55 are still in this

The channel has a delay element 12, which causes a certain difference in the running time between equivalent signals in channel 4 of the useful signal and in channel 5 of the interference. In the event that the signals in channel 4 of the near-signal, due to the longer signal path, slow down even more than in channel 5, element 12 may fall out.

The diagram of the device is applicable for the transfer of ipformatsin from the underlying response device to the fixed questioning device.

To explain, it was assumed that the interference signal always covers only one frequency section.

Claims (1)

1. US Patent No. 3665321, cl. H 04B 1/10, 23.05.72.