SU403110A1 - - Google Patents

Description

one

The invention relates to the field of communication technology, namely to television broadcasting systems.

A device for transmitting time signals over a television wedding channel is known, comprising on the transmitter side a test line signal generator, a signal input unit, a time signal source, a marking unit, a correction definition unit, an encoder, and on the receiving side a test line signal selector, a demodulator, Bullet selector, decoder, variable delay unit.

A disadvantage of the known device is the lack of efficiency and noise immunity of transmission.

The aim of the invention is to improve the efficiency and noise immunity of time signal transmission.

In the device of the proposed design, on the transmitting side, the input of the inserted modulator and the input of the marking unit are connected to the outputs of the signal generator of test lines, the second INPUT module is connected with the output of the encoder, and the outputs of the modulator and. The marking unit - with the inputs of the input unit for the signals of the test lines; on the receiving side, the output of the signal selector of the test lines is connected to the input of the decoder via a demodulator, service, and

to select a coded signal of a numerical correction, and between the output of the selector of the tagged pulse and the input of the non-time delay block, the block is connected

delays, the other inputs of which are connected to the delay setting unit, and the counting inputs of the delayed-delay unit and the variable delay unit are connected via a switch to the output of the pulse generator

high stability and with high speed source.

FIG. 1 shows the block diagram of the transmitting part of the device; in fig. 2 - block s.hema receiving part of the device.

The onable device contains on the transmitting side (Fig. 1) a time source 1, a correction determination unit 2, a marking unit 3, a generator of 4 test line signals, a signal input unit 5

test lines, modulator 6, kadr 7, and on the receiving side (Fig. 2) - selector 8 signals of test lines, selector9 of the marked signal, demodulator 10, block 11 constant delay, block 12 time delay, block 13 set delay, generator 14 high stability pulses, a decoder 15, a switch 16, and a time signal source (not shown in Fig. 2). The described device works as follows; nm way; : ...;,:; From the source of time signals, signals of an irreducible time scale, the duration of which is equal to the period of the following test line signals (or identification signals), are sent to start up the unit to determine the correction made, for example, as a digital time interval meter, and to the marking unit, which is also served One of the components of the control signals of the test lines, for example, a reference signal for measuring the amplitude-frequency characteristic, which is a pulse with two reference levels. This signal is generated in generator 4 during the transmission of this test string. The start of generator 4 is carried out by pulses generated by a signal inserter 5, to the input of which a full television signal is applied. The location of the triggering pulses generated by the block corresponds to the position of the frame damping pulse into which the test lines are inserted. When a signal joins with the signals transmitted by time, the marking unit provides for the modulation of a parameter of one of the components of the control signals of test lines, for example, switching the signal polarity. At the same time, a signal of a certain form will be transmitted as part of the test line at this moment. It should be noted that such a change in the signal does not affect the performance of its main function. Thus, during the coincidence of the signals in one of the zeros of the full television signal, a tagged signal will be transmitted, which is the reference for restoring the time scale. The signal from the output of the marking unit enters the signal input unit 5, and is also fed to the second input of the correction correction unit 2. The marked signal ensures the block 2 to stop, which corresponds to the end of the measurement of the interval Tn, equal to the delay of the beginning of the marking signal relative to the irregular time mark. At the outputs of block 2, a parallel code of a numerical correction is formed, corresponding to the value of Tn. These signals are fed to the inputs of encoder 7, which converts information about the duration of the interval -Gp into a serial code, which is necessary to transmit this correction using the test signals of the test lines. This encoder can be implemented, for example, in the form of a parallel code converter into a serial binary code with a period of following code elements equal to the frame length th. The encoder output is connected to a modulator, to the second input of which 4 separate components of the control signals of test lines or identification signals, such as sinusoidal nozzle packets, used to transmit information about numerical corrections, arrive from generator 4. 5 10 15 20 25 30 35 40 45 50 55 60 65 Each code element from the output of the encoder sequentially with a frame rate modulates defined parameters of selected components of their test signals of test lines or identification signals (for example, the phase of sinusoidal nozzle packets). The modulator output signals, carrying the information about the phase corrections, the signals from the output of the marking unit, which are the reference for restoring the time slides, as well as the other components of the test lines and the identification signals from the generator 4 output, add up to the full television signal in block 5 and enter the television broadcast channel (not shown in Fig. 1). From the output of the input unit of the television test lines, television signals containing test lines with marked and coded signals are fed to the television fuzz channel - to the cable line, to the television transmitter (pa not shown) and so on. At the receiving side of the prin TV signal signals, the test line signal selector selects the test line signals delayed relative to the transmitted signals by Tp - the propagation time on the television broadcast channel and highlighted The signals are fed to the input of the selector of the marked signal, which selects the marked signal, and to the input of the demodulator 10, which extracts the sequentially coded correction signal. The marked signal from the output of the selector 9 is fed to the input of a constant delay unit and a variable delay unit. The magnitude of the delay in block 11 is unchanged at a constant distribution time of the signals Tj3 in the channel of the television broadcast and is set in advance by the delay setting unit with regard to said signal propagation time. A constant delay unit together with a delay setting unit can be executed, for example, in the form of an electric counter with a preliminary setting of the capacity of the counter, which reads the pulses of the pulse generator. The signal from the output of the constant delay device is fed to the input of a time delay unit, made, for example, in the form of an electronic counter of a constant capacitance, the initial state of which is determined by the decoded numerical correction signals coming from the decoder. The decoder can be implemented, for example, in the form of a converter of serial binary code into parallel code. The maximum delay of the variable delay device is Tsper. The max is set to be equal to or longer than one frame, and the delay in the constant delay block is set to a longer time interval required to transmit the required number of code points. The variable delay block is performed in such a way that a valid delay in