SU949829A1 - Signal transmission device - Google Patents

Description

(54) SIGNAL TRANSMISSION DEVICE

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The invention relates to communication technology and can be used in time-division / channel separation information transfer systems.

A device for transmitting signals with frequency modulation and time division channels is known, comprising a serially connected phase detector, an active low pass filter, a memory key, a serially connected synchronizer, a switch, a controlled oscillator connected to the input of the phase detector, the other input of which is connected to a generator reference frequency 1.

However, the output signal of the known device has a phase discontinuity due to disconnection from the path by the time of generator tuning, which leads to the expansion of the transmitted spectrum, reduction of information content with transmission over several channels, and limiting the system performance.

The purpose of the invention is to increase the speed of signal transmission over several radio channels without breaking the phase.

This goal is achieved by the fact that in a known device for transmitting signals with frequency modulation and time division of channels containing a serially connected phase detector, an active low pass filter, a memory key, serially connected synchronizer, switch, controlled oscillator connected to the input of the phase detector , the other input of which is connected to the reference frequency generator, is introduced in series with a highly stable voltage source, a shift signal generator, Q ha and an adder, connected to the second input of the controlled generator, serially connected trimming pulse extractor and switching pulse shaping unit, the output of which is connected to the control, memory key input, while the synchronizer output is connected to the control input of the shift signal generator and to the first input of the allocation unit adjustment pulses, the second input of which is connected to the output of the commutator.

FIG. 1 is a circuit diagram of the proposed device; in fig. 2 shows voltage and signal diagrams in a device circuit.

The device for transmitting signals with frequency modulation and time division channels contains a phase detector 1, an active lowpass filter 2, a key 3 of memory, a synchronizer 4, a switch 5, a controlled oscillator 6, a reference frequency generator 7, a source of highly stable voltage, a driver 9, a shift signal, an adder 10, a trimming pulse extraction unit 11, a switching pulse generation unit 12, as well as a modulator 13 and a harmonic filter 14.

The device works as follows.

Useful information from the input of the switch 5 (Fig. 2a), controlled by the synchronizer pulses of the synchronizer 4 (Fig. 26), is fed to the input of the controlled generator b through the modulator 13. At this, the carrier frequencies of the controlled generator 6 are modulated. Harmonic filter 14 provides suppression of carrier harmonics present in its spectrum. The frequency stability of the controlled oscillator 6 is determined by a phase locked loop (PLL) operating at the fundamental frequency f | and consisting of a generator 7 of the reference frequency of the phase detector 1, an active low pass filter 2, an adder 10, and a key 3 of the memory. The adjustment is made during a certain pulse selected in the modulating signal (for example, a frame synchronization pulse) allocated by the adjustment pulse extracting unit 11 (Fig. 2c) and entering the switching pulses into the generation unit 12. The generated switching pulses, -admissions to the memory key 3, close the PLL of the controlled oscillator b, and the frequency fi is adjusted by the signal of the reference frequency generator 7.

The error signal received as a result of the adjustment of the controlled generator by the PLL circuit is memorized by the memory key 3 until the next adjustment pulse arrives. C) the steel carrier frequencies jj .... emitted in the frequency transmission gaps are obtained by applying an additional pulse signal from a highly stable voltage source 8 (Fig. 2 g) through the shift signal generator 9.

controlled by the sync pulses, to the error signal coming from the key 3 of the memory to the second input of the controlled oscillator b (Fig. 2e, e). In this case, part of the voltage is applied to the input of the key 3 of the memory entering the PLL ring, which ensures the same stability of the main fi and shifted frequencies iz ... arriving at the output of the device (Fig. 2 g) through the harmonic filter 14.

Thus, the proposed device allows to increase the transmission rate of a highly informative signal over several radio channels by no less than 10 times with a high stability of the output frequencies, without phase discontinuity and expansion of the occupied frequency band.

Claims (1)

Invention Formula A device for transmitting signals with frequency modulation and time division of channels, containing a series-connected phase detector, an active low-pass filter, a memory key, a series-connected synchronizer, a switch, a controlled oscillator connected to the input of a phase detector, the other input of which is connected to a generator frequencies, characterized in that, in order to increase the speed of transmission of a signal over several radio channels without interrupting the phase, serially connected sources are introduced into it a sub-stable voltage, a shift signal conditioner and an adder connected to the second input of the controlled generator, serially connected trimming pulse extractor and switching pulse shaping unit whose output is connected to the control key of the memory key, while the synchronizer output is connected to the control input a shift signal generator and to the first input of the trimming pulse extractor, the second input of which is connected to the output of the switch. Sources of information taken into account in the examination 1. Swiss patent No. 518031, cl. H 03 B 3/10, 1976 (prototype). 1 / year /