SU1195461A1 - System for repeating call tone via channel with delta modulation - Google Patents

Abstract

The invention relates to the field of telecommunications and provides a rise in the noise immunity of the broadcast of a dial tone. On the transmitting side, an input tone signal arrives at the receiver 4 of the tone call and at the delta modulator 2. The pulses of the clock generator 1 delta modulator 2 converts the input signal to pulse sequence. When a tone call signal arrives at a frequency i at the output of the receiver 4 of the tone you W ft: t-aK .--: e call, a control signal is generated, postoyuyutsya to the switch (K) 5. In this case, through K 5 to channel 6 with delta -modulation receives a pulse sequence of the form of a square wave with a period of 1 / f, formed by a divider of 3 frequencies on the pulses coming from the clock generator 1.. On the receiving side, the pulse sequence of the form of a square wave enters the delta-demodulator 7 and through the low-pass filter 10 to the receiver9 of a tonal call. The receiver 9 of the tonal call forms a control signal, which is sent to K 8. In this case, K 8 (L is sent to the system output by a signal from the low-pass filter 10. When transmitting the main information on the transmitting side through K 5, channel 6 is delta -modulation receives a pulse sequence from the delta modulator 2, and on the receiving side, a signal from the costa of the delta demodulator 7, 1 or 10 is transmitted through the K 8

Description

The invention relates to telecommunications, in particular to communication systems with time division of channels and delta modulation.

The aim of the invention is to simplify the device and increase the noise immunity of broadcasting a tonal call.

 The drawing shows a structural electrical circuit of the system of broadcasting a tone call over a channel with delta modulation.

The system of broadcasting a tone call over a delta-modulated channel contains a clock generator 1, a delta modulator 2, a divider 3 frequencies on the transmitting side, a dial tone receiver and a switch 5, channel 6 with delta modulation, and on the receiving side delta demodulator 7 switch 8, receiver 9 dial tone and filter 10 low frequencies ..

The device works as follows.

The input tone signal is fed simultaneously to the input of the delta modulator 2 and to the input of the receiver 4 tone call. Delta-modulator 2 at the time points determined by the pulses from the clock generator 1, the delta transforms the input tone signal into a pulse sequence received at the second input of the switch-. ra 5. Connected to the clock generator 1 divider 3 frequency, having

the division factor r-z produces at its output a pulse output sequence a square wave with

period of impulses -, coming in turn, at the first input of the switch 5.

When broadcasting via a tone call signal channel with a frequency f, a 4 tone call receiver is triggered.

At the same time, at the output of the tone call receiver 4, a control signal is generated that acts on the control input of the switch 5 and provides the connection of channel 6 with delta modulation to the output of the frequency divider 3.

 As a result, in channel 6 with delta-modulation, there will be a pulse sequence of the form of a square wave with a pulse following period, which passed the 1P filter

low frequencies, eliminating the harmonic components in the spectrum of the pulse sequence, is converted into a tone signal with a frequency f, which will trigger the receiver 9 tone call.

At the output of the receiver 9 tonal

A control signal will be generated from which the switch 8 provides a connection to the output of the low-pass filter 10, i.e. recovery will occur.

call tone signal. In the absence of broadcasting via the tone call signal channel, when basic information is transmitted to channel 6 with delta modulation, switch 5 will switch on the output of delta modulator 2 and, therefore, switch 8 will connect the output of the system by switch 8 module of torus 7 realizing

with a certain accuracy, the restoration of the original tone of the basic information.

Claims (1)

Invention Formula A delta-modulated channel call broadcasting system, comprising a clock generator, a delta modulator, a frequency divider, a tone call receiver and a switch on the transmitting side of the delta modulated channel, the delta modulator input and the tone receiver input the call is combined, the control input of the delta module is connected to the first output of the clock generator, the second output of which is connected through the frequency divider to the first input of the switch, the output of the delta module is connected to the second input the switch whose control input is connected to the output of the dial tone receiver, the switch output is connected to the delta-modulated channel, and on the receiving side of the channel With delta modulation, a delta demodulator, a switch and a dial tone receiver, the delta demodulator input is connected to a delta modulation channel, and the output of the delta modulator is connected to the first input of the switch, characterized in that devices and enhancements 3 1195461 translation of sound modulation is introduced to the bottom call, on the transmitting side of the channel, and the output of the lower filter With delta modulation, the frequency divider is connected to the second comtot input and is divided by the del-mutation factor and the input of the tonal call receiver, whose output is connected --- where t is the frequency.calling control input of the switching signal, the period following it -ra and lowpass filter input pulses of the clock generator, and is connected to the input of the delta-demodule on the receiving side of the channel from the delta-torus.