RU2000673C1 - Device for receiving additional information digital signals - Google Patents

Abstract

Using; radio engineering, data transmission and reception systems - digital signals of additional information. SUMMARY OF THE INVENTION: A device for receiving digital additional information signals comprises a channel selector 1, an intermediate frequency amplifier 2, a video processor 3, interface units 4.1 and 4.2, a teletext decoder 5, an additional information presence determination unit 5, and a control unit 6. The invention improves the processing speed of information. 2 ill.

Description

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The invention relates to radio engineering, in particular, to a system for transmitting and receiving data of digital additional information signals (magazines) as part of a television signal, and can be used in existing collective and individual television reception networks to receive alphanumeric and graphic information by a subscriber .

The aim of the invention is to increase the speed of information processing.

Figure 1 presents a functional structural diagram of the proposed device; Fig. 2 shows a control unit.

The device comprises a channel selector 1, an intermediate frequency amplifier 2, a video processor 3. the first and second interface units 4.1 and 4.2, a programmable unit 5 for detecting, processing and recording additional information, a control unit 6. In this case, the first input of the channel selector 1 is connected to the input of the device, the output is to the input of the intermediate frequency amplifier 2, the first output of which is connected to the input of the video processor 3, the second output is to the input of the second channel selector 1, the group of outputs of the video processor 3 is connected to the first group of inputs of the block .4.1. the first group of outputs of which is connected to the first group of inputs of the programmable block 5 for determining the availability, processing and registration of additional information.

The control unit 6 (see Fig. 2) comprises a buffer memory 7 (memory), a digital-to-analog converter 8 (DAC), a controlled range switching key 9.1, and a frequency-controlled controlled key 9.2. The outputs of block 4.2 (see Fig. 1) are connected to the inputs of blocks 7, 8, and 9.2, the outputs of block 7 are connected to the corresponding inputs of block 9.1, the control input of block 9.2, controlled by the control input of block 6, is connected to the third output of amplifier 2 (see figure 1). The outputs of blocks 8, 9.1 and 9.2. which are the switching outputs of the radio channels of block B (see Fig. 1), are connected to the corresponding switching inputs of the channel selector 1.

The device operates as follows. The broadcast television radio signal is fed to the input of the device connected to the input of the channel selector 1. At the output of the selector 1, a signal of the corresponding channel at the intermediate frequency is extracted. From the output of the selector 1 channels, the intermediate frequency signal is fed to the input of amplifier 2, the output of which

the envelope of the signal (video signal) is extracted. In addition, the amplifier 2 has automatic gain control (AGC) and automatic frequency control (AFC) systems. The AGC system stabilizes the gain in selector 1 and block 2, which is achieved by connecting the second output of amplifier 2 to the second input of selector 1.

AFT system is used to provide

frequency settings for the maximum reliability of the received information. The AFC system is connected through the third output of the selector 2 to the control input of unit 6

5 (block 9.2. FIG. 2).

The video signal (full color television signal) allocated at the output of the selector 2 is fed to the input of the video processor 3.

0There are two options.

Option 1 - the signal supplied to the input of the video processor 3, contains digital signals of additional information. Option 2 - the signal arriving at

5 input of the video processor 3, does not contain digital signals of additional information.

In the first case, information packets, a clock signal, which is a product of phasing the internal highly stable generator and received packets, as well as other synchronizing pulses of lines, fields, etc., are allocated to the group of outputs of the video processor 3.

5 These signals from the group of outputs of the video processor 3 are fed to the first group of inputs of block 4.1, in which the received information is recorded, its preliminary processing and reading into block 5

0 determining the availability, processing and recording of additional information. In addition, in block 4.1, bytes of overhead information and own data information are extracted. In bytes of service information, the bit synchronization code, the number of the transmitted log and other attributes associated with the format and display of pages of alphanumeric information (on the screen) are selected

0 display, printer, etc.)

The selectable bytes arrive at block 5. At the same time, when additional information is received at the outputs of the video processor 3, the corresponding information is transmitted to block 5. through block 4.1, which gives the command to connect the AFC system located in selector 2. This process is carried out by the following images AFC g of the third output selector 2 P. senior / hpet H.I management

key 9.2 (see Fig. 2), which opens when a command signal is received from block 5 through block 4.2 to the input of key 9.2. In this case, through the public key, the AFC circuit is connected to the channel selector 1, i.e. from the corresponding switching output of block 6, it is connected to the corresponding switching input of channel selector 1.

Packets of digital signals of additional information, the duration of which is equal to the length of one line of a television raster, contain information that allows, upon receipt of the packet, to determine the presence of errors in the received information. The presence of errors is recorded in block 5 after appropriate processing of the received information according to a known algorithm. The frequency adjustment is carried out according to the criterion of maximum reliability of reception, after which, by the command of block 5, block 9.2 of block 6 turns off the AFC system through block 4.2, and the optimal tuning frequency for this radio channel is stored in block 5.

In option 2, when there are no digital signals of additional information in the received radio channel, information from the group of outputs of block 4.1 to block 5 receives information about the absence of digital signals in this radio channel. In this case, in block 5, radio channel switching signals are generated within a given radio frequency range. These signals through the first group of outputs of block 5 in binary form through block 4.2 are fed to the input of the digital-to-analog converter 8 (Fig. 2), which is part of the control unit. An analog voltage is generated at the output of the DAC, proportional to the binary code at its input. This analog voltage from the output of control unit 6 is connected to the corresponding switching input of channel selector 1. In this case, as the analog voltage changes, the frequency changes until the frequency at the output of the selector 1 is equal to the nominal value of the intermediate frequency.

So there is a search for additional information signals on all radio channels of this range.

In the absence of additional information signals in this range, block 5, in accordance with the operation algorithm, makes a decision to switch to another range. This operation is carried out using block 5, which, in accordance with a predetermined program, produces a sequence of pulses. These pulses through

the first group of outputs of block 5 in bits go to the group of inputs of block 4.2. which is made functionally in the form of a shift register. At the output of block 4.2-5, a parallel binary code is generated. which is fed to the inputs of the control unit 6. The first bits of the binary code are fed to the input of block 7 and are used to form a voltage drop, which enables the desired radio frequency range to be switched on through block 9.1, by connecting the corresponding output of block 9.1, which is the switching output of the radio channels of block 6, to the corresponding input 5 of switching selector 1 channels.

The subsequent bits of the binary code are input to the DAC 8 and serve to switch the radio channels within the range, as described above.

0 Block 7 fixes this range to

the arrival of the transition team to another.

Block 5, which is part of the device, ensures the operation of the device according to the following algorithm. Sequentially bypasses 5 all ranges, fixing the radio channels in which digital signals of additional information are transmitted, fixing these channels in memory and the optimal tuning frequency for each channel. The time schedule for the occurrence of information signals over all radio channels is 0, and on the basis of this it forms the optimal algorithm for processing all information.

Thus, the proposed device 5 allows you to automatically select the optimal algorithm for processing and storing an array of data (alphanumeric and graphic information) transmitted via various TV broadcasting channels while minimizing the error per bit of received information.

Claims (1)

SUMMARY OF THE INVENTION A device for receiving digital signals of additional information, comprising 5 series-connected channel selector, a radio channel unit, a video processor and a first interface unit, the first input of the channel selector is an input of the device, its second input is connected to the second 0 output of the radio channel unit, characterized in that a programmable block for determining the presence, processing and recording of additional information, a second pairing unit 5 and a control unit, a control input are introduced in series orogo connected to the third output of the radio channel block, the outputs of the switching control unit of radio channels connected to respective inputs of the selector switch channels, the group of inputs of the programmable unit for determining the presence, processing and recording of additional information connected to the outputs the first coupler, and the second group of outputs with the second inputs of the first coupler. Fig 2