SU934575A1 - Device for transmitting and receiving complementary information in communication channel - Google Patents

Description

(54) TRANSMISSION AND RECEIVING DEVICE ADDITIONAL INFORMATION IN THE COMMUNICATION CHANNEL

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The invention relates to radio engineering and can be used to transmit and receive additional information signals in a communication channel involved in the transmission of programs,

A device for transmitting and receiving additional information in a canapé is known, containing on the transmitter side an additional information sensor and series-connected reference generator, modulator and adder, and on the receiving side series-connected band-pass filter and detector p 3

However, this device does not provide sufficient noise immunity of additional information signals for different types of broadcast programs, for example, speech, music, etc., due to the restriction on the choice of permissible level of additional information signals. Increasing the level of these signals leads to distortion of the signals of broadcast programs.

The purpose of the invention is to increase the noise immunity of the transmission of signals for additional information without distorting the main signals of the broadcast programs.

To achieve the goal, a device containing a sensor of additional information on the transmitting side and

Claims (1)

10 consecutively coupled reference oscillator, modulator and adder, and on the receiving side a series-connected band-pass filter and detector, an amplitude detector and integrator connected in series are introduced on the transmitting side. In this case, the input of the amplitude detector is combined with the signal input of the adder. The output of the integrator is connected to the input of the modulator, which is balanced. The output of the sensor for additional information is connected to the modulating input of the reference generator. At the receiving side, the output of the detector is connected to the input of the integrator, the output of which is the output of the device. The drawing shows the structural electrical circuit of the device. The device for transmitting and receiving additional information in the communication channel contains, on the transmitting side, consecutively connected sensor 1 of additional information, reference generator 2, modulator 3 and adder 4, as well as an amplitude detector 5 and integrator 6 connected in series. The input of the amplitude detector 5 is combined with the signal input of the adder 4, the output of the integrator 6 is connected to the input of the modulator 3, which is balanced. On the receiving side, the output of the band-pass filter 7 through the detector 8 is connected to the input of the integrator 9 whose output is the output of the device. The device works as follows. From the program source, a broadcast signal is fed to detector 5, where it is detected. From the output of integrator 6, a broadcast signal f is sent to one of the inputs of the balanced modulator 3. Its second input from reference oscillator 2 receives a signal modulated by the additional information signal from sensor 1; In this case, at the output of the balanced modulator 3, a modulated signal appears, the amplitude of which is correlated with the amplitude of the envelope of the vegetative signal. From the output of the balanced modulator 3, the modulated additional information signal is fed to the adder 4, where it is matched with the broadcast signal and transmitted to the communication channel. On the receiving side, the subscriber receives a sum signal in which the additional information signals are masked by the components of the broadcast program signal spectrum. . Therefore, from the point of view of better masking of the additional information signals, the frequency of the reference oscillator 2 is selected in the frequency range from 200 to 1000 Hz, since the probability of occurrence of the spectral components in this frequency range with various types of signals of the broadcast program programs is greatest. At the same time, the components of the spectrum of the additional information signal and the spectrum components of the broadcast program signal are separated by a bandpass filter. In this case, the useful signal will be additional information, and the noise will be the signal of the broadcast programs. After being detected in the detector 8, they arrive at the integration block 9, where the additional information signals supplied to the output of the block 9 are extracted. The proposed device allows the additional information to be transmitted over a busy communication channel with the level of the additional information signals almost equal to the envelope level. broadcast signal. In this way, a high signal-to-noise ratio is provided for the signals of additional information without distorting the signals of the broadcast programs. Formula of the Invention A device for transmitting and receiving additional information in a communication channel, containing on the transmitting side an additional information sensor and serially connected reference oscillator, modulator and adder, and on the receiving side serially connected bandpass filter and detector, characterized in that To increase the noise immunity of the transmission of additional information signals without distorting the main signals, an amplitude detector and an integrator are inserted on the transmitting side; In this case, the input of the amplitude detector is combined with the signal input of the adder, the integrator's output is connected to the modulator input, which is balanced, the additional information sensor output is connected to the modulating input of the reference oscillator, and on the receiving side, the detector output is connected to the input of the integrator, the output of which is the output of the device. Sources of information taken into account in the examination 1, German Application No. 2350081, Cl, H 04 And 7/04, published, 27.07.78, (prototype).