SU1246415A1 - Device for transmission and reception of two television signals - Google Patents

Abstract

The invention provides improved quality of received signals by increasing the horizontal resolution. The device contains on the transmit side a switch. torus (k) 1, sync generator 2, delay line (LZ) 3 and two similar processing units (VO) 4.5. Each of these BDs contains K 6, LZ 7, two low-pass filters (LPF) 8.9, two equalizing LPs 10, 15, two modulators 11, 12, two adders 13, 14, differentiation unit 16, and 17 , phase shifter 18 at 90 °, band-pass filter (PF) 19. At the receiving side, the device contains an amplitude selector 20, K 21, two similar BO 22, 23, including K 24, LZ 25, subcarrier allocation unit 26 subcarrier frequency 27, phase shifter 28 at 90 ° C, two synchronous detectors 29, 30. The first signal goes to the BO 4 directly, and the second signal through LZ 3 (per line) - on BO 5. In BO 4 on the amount (L yn (“uG;

Description

Torus 13 receives signals of odd lines passed through LZ 7, LPF 8, equalizing LZ 10 and differentiation unit 16, and signals of even lines, pass through LPF 9 and equalizing LZ 15, In adder 13, the signals of even lines are predistorted to reduce the visibility relates to television and can be used for simultaneous transmission of two television (tv) signals over one standard communication channel.

The purpose of the invention is to improve the quality of received signals by increasing the resolution, horizontally,

Fig. 1 shows the structural electrical circuit of the device proposed; FIG. 2 shows diagrams explaining the operation of the device; FIG.

The device for transmitting and receiving two TV signals contains on the forward side the first switch 1, the sync generator 2, the first delay line 3 (LZ), the first 4 and the second 5 processing units. The first processing unit 4 contains the second switch 6, the second LZ 7, the first low-pass filter 8 (LPF), the second LPF 9, the first equalizer LZ 10, the first 11 and the second 12 modulators, the first 13 and second 14 adders, the second equalizer LZ 15 , differentiation unit 16, subcarrier generator 17, first phase shifter 18 by 90, band-pass filter (PF) 19, the second processing unit is made similar to the first one.

On the receiving side, the device contains an amplitude selector 20, the first switch 21, similar to the first 22 and second 23 processing units, including the second switch 24, LZ 25, subcarrier allocator 26, subcarrier generator 27, second phase shifter 28 by 90, first 29 and second 30 synchronous detectors. A device for transmitting and receiving two TV signals operates as follows.

The crosses of the quadrature interference from the signals of the odd lines after the partial suppression of one sideband in the FS 19, the Clock Generator 2 generates switching signals with a frequency equal to half the line frequency. From K 1, the common signal arrives at the receiving side, 2 Il.

The first TV signal (Fig. 2a, conditionally shows rows as rectangles) is fed to the input of the second switch 6, the second input of which from the clock generator 2 receives the switching signal with the frequency fo, and fo is equal to half the frequency of the rows fo / 2. From the first output of the second switch 6 odd lines of TV

About the signal (Fig, 2) through the second LZ 7, the first LPF 8 and equalizing LZ 10. arrive at the first input of the first modulator 11, the second input of which receives the subcarrier oscillation

5 frequency phase O from the generator 17 subcarrier. Signals of odd lines transferred to the subcarrier from the output of the first modulator 11 are transferred to the first input of the second adder 14.

20 From the output of the equalization LV 10, the signals of the odd lines are fed through the differentiation unit 16 to the first input of the adder 13, the second input of which receives the signals of the even lines

 (Fig. 2d) from the second output of the second switch 6 via the second low-pass filter 9 and J equalizing LZ 15, From the output of the first adder 13, the predistorted signals of the even lines arrive at the first input

30 of the second modulator 12, the second input of which receives the oscillation of the subcarrier frequency of phase 90 from the output of the generator 17 subcarrier through the first phase shifter 18,

35 From the output of the second modulator 12 transferred to the subcarrier predistorted signals of even lines arrive at the second input of the second adder 14, from the output of which the sum signal (FIG. 2) through the PF 19 goes to the first input of the first switch 1, P PF 19 partially one bo3 is suppressed

Cova strip. Even-row strings are predistorted to reduce the visibility of cross-quadrature interference from odd-row strings after partial suppression of one sideband.

The second TV signal is delayed in LZ 3 for the duration of the line relative to the first TV signal, then processed in the second processing unit 5 similarly to the first TV signal and fed to the second input of the first switch 1 (Fig. 2e). The delay in LZ 3 is necessary 1 That the condensed signals of lines of the second TV signal get into the vacant - lower-case intervals of the first TV signal. In this case, the first and second TV signals must be synchronous and in-phase. The third input of the first switch 1 is given a switching signal of the hour

totoy

Yo

The common signal (Fig. 2) from the output of the first switch 1 through the transmitter, the communication channel and the high-frequency cascades of the receiver is fed to the input of the amplitude selector 20 and the first switch 21 of the receiving part, which also switches with the frequency fo (the amplitude selector has the line frequency is divided in half). The first output of the switch 21 receives signals from the rows of the first TV signal, and the second output signals from the rows of the second TV signal. The signals of the rows of the first TV signal are fed to the first inputs of the first 29 and second 30 synchronous detectors, as well as to the first input of the subcarrier allocation unit 26. In an under carrier allocation unit 26, the frequency and phase of the subcarrier produced by the subcarrier frequency generator 27 and received from the transmitter are compared.

Information about the frequency and phase of the subcarrier is transmitted in a protective flash interval located on the rear ledge of the horizontal damping pulse. As a result of the comparison, a control voltage is generated, which adjusts the frequency and oscillation phase of the oscillator 27 of the subcarrier frequency. From the generator output 27, the subcarrier subcarrier enters the second input of the first synchronous detector 29 and through the second phase shifter 28 the subcarrier with the phase shifted by 90 enters the second

input of the second synchronous detector 30. At the output of the first synchronous detector 29, signals of odd lines of the first TV signal are selected, and at the output of the second synchronous detector 30 — predicted signals of even lines of the first TV signal.

To bring the TV signal to the standard TYPE, the signals of the lines from the output of block 30 are delayed by the length of line H in LZ 25 and are then fed to the second input of the second switch 24, the first input of which is followed by odd lines from the output of the first synchronous detector 29. the third input of the second switch 24 is supplied with a switching signal with the frequency fo, resulting in

The output of the second switch block 24 signals of the rows of the first TV signal appear in the original sequence.

The second TV signal recovers 25 seconds in the second processing unit 23, similar to the first TV signal.

Claims (1)

Invention Formula A device for transmitting and receiving two television signals, comprising on the transmitter side a first switch, a synchronizer, a first delay line, a first processing unit, the first input of which is the first the input of the device, the second processing unit, the first input of which is connected to the output of the first delay line, the input of which is the second input of the device, the output of the synchronizer is connected to the second inputs of the first and second processing units, each of which contains a second switch, the first input of which is the first the input of the processing unit, and the output is connected to the input of the second delay line, the first and second low-pass filters, the first equalizing delay line, the first and second modulators, the first and second adders, the second input of the second th switch B. It is the second input of the processing unit, on the receiving side an amplitude selector, the output of which is connected to the first input of the first switch, the first and second processing units, each of which contains a second commutator, a delay line characterized by the fact that improving the quality of received signals by increasing resolution horizontally, on the transmitting side, a second equalizing delay line, a differentiation unit, a subcarrier generator “phase shifter by 90, a band-pass filter, and a second output of the second switch are connected through a series-connected second the low-pass filter and the second equilibrium delay line with the first input of the first szgmmator, the rotor output is connected to the first input of the second modulator, the output of the second l After the delay, the first low-pass filter is connected in series through the first equalizer, the first equalizing delay line and the differentiation unit to the second input of the first adder, the input of the differentiation unit is combined with the first input of the first modulator, the output of which is connected to the first input of the second adder, the second input is connected to the output the second modulator, the subcarrier generator output is connected to the second input of the first modulator and through the phase shifter to 90 with a second input of the second modulator, the output of the second adder is A bandpass filter is connected to the first input of the first switch, the output of the first delay line is connected via a second processing unit to the second input of the first switch, the third input of which is connected to the output of the clock generator, the output of the first switch is the output of the transmitting side of the device, at the receiving On each side, a subcarrier allocation unit, a 90 ° phase shifter subcarrier generator, first and second synchronous detectors are inserted, the first and second outputs of the first switch are connected respectively to the first inputs of the first and second processing units, the second inputs of which are connected to the output of the amplitude selector and the outputs are respectively the first and second outputs of the device, the first input of the block of the last subcarrier is connected to the first inputs of the first and second synchronous detectors and is the first The first input of the processing unit, the output of the first synchronous detector is connected to the input of the second switch, the output of which is the output of the processing unit, the output of the second synchronous detector is connected to the second input of the second switch through the delay line, the output of the subcarrier extractor is connected via a sequential connected subcarrier generator and phase shifter at 90 it is connected to the second input of the second synchronous detector, the input of the 90® phase shifter is combined with the second input of the first synchronous detector, the second generator output, brings The rails are connected to the second input of the subcarrier allocation unit, the third input of the second switch is the second input of the processing unit, the input of the amplitude selector is connected to the second input (First switch i and is the input side of the device).