SU1225046A1 - Receiver of selective ringing signal with reference signal - Google Patents

Abstract

The invention relates to multi-channel communication systems and can be used for selective calling from serviced stations included in the linear path of the system over a service link. The number of received call frequencies is increased. The device includes an amplifier-limiter 2, a front driver (FF) 3, a detector 4, a switch 5, a reversible counter 6, a clock generator 7 (GTI), a decoder 8, and a coincidence pulse counter 9 (SIS). The operation of the device is divided into cycles, each of which consists of four phases of the same duration. The division into cycles and phases carries the GTI 7. The SIS 9 bit determines the number of cycles needed / to make a decision about the presence of a ring signal. SIS 9 protects the device from random conversational signals with a frequency close to the reference frequency. An overflow of SIS 9 indicates an abnormal frequency at the input signal, and at the output of SIS 9 a device trigger signal appears. The detector 4 additionally protects the device from conversational signals. The goal is achieved by the introduction of FF 3, detector 4, switch 5 and SIS 9, 1, or ill. g you O1 about 4 F

Description

The invention relates to multichannel communication systems and is intended to provide the possibility of selective calling from serviced stations that are part of the linear path of the system, over the service link. .

The aim of the invention is to increase the number of received ring frequencies.

The drawing shows a block diagram of a selective call receiver with a reference signal. ,

The device contains the first input 1 of the device, the amplifier-limiter 2, the front driver 3, the detector 4, the switch 5, the reversing counter 6, the clock pulse generator 7, the decoder 8, the coincidence pulse counter 9, the second input 10 of the device.

The proposed device works as follows.

The call signal of the service link, coming from the channel of the service link, arrives at the amplifier-limiter 2, which is predetermined to amplify the ring signal to the desired value and limit it. From the output of the amplifier-limiter 2, the ringing signal arrives at the shaper of 3 fronts, where its shape is transformed into a powerful one with the same frequency. From the output of the 3-front generator, the ringing signal arrives at the switch 5, to the second input of which from the tone call generator (not shown), located in the transmitting part of the service communication systems, the reference signal is continuously received in the form of a pulse sequence with the reference frequency, which is equal to the call frequency of the service call assigned to this station. If the ringing (F) and reference (RD-) frequencies are close or

 Sew on

are equal, i.e. if the conditions are met

on

& F,

(one)

where l f is the response frequency band

receiver,

then the receiver is triggered and a potential emerges at its output. If this

the condition is not fulfilled, the receiver does not work and the ringing potential does not appear at the output.

The operation of the receiver is divided into cycles, each of which consists of four phases of the same duration. This division into cycles and phases is carried out by a clock pulse generator 7. In the first phase of each cycle, from the output of the generator 7, a signal appears, setting the reversible counter 55 6 to the initial state.

In the second phase of each cycle at the command of the generator 7. arriving at the corresponding

0

s

0

5 o

0

0 5

The main input of the switch 5, the switch 5 connects the reference signal to the input of the reversible counter 6.

By the beginning of the third phase of the cycle, a logical combination of ones and zeros appears at its outputs, corresponding to the number of reference frequency pulses counted during the second phase. With the beginning of the third phase, the switch 5 disconnects the reference signal from the output of the addition of the reversible counter 6 and connects the output of the 3 front generator to the subtraction input of the reversible counter 6, providing the subtraction of the counted number of pulses. If the ring frequency is larger than the reference frequency, then for the modular operation of the overflow output of the reversible counter 6, is connected to the input of the switch 5. Then at the moment the reversing counter 6 goes through zero, the output of the overflow occurs a pulse switching the output of the 3 front generator to the folding reverse input counter 6.

The receiver response band is determined by connecting the lower bits of the 6 k reversible counter. decipheror 8, and in this case it is a multiple of 2 - 1 and is -. .

If condition (1) is fulfilled, then at the moment of termination of the third phase of the cycle, all outputs of the high bits of the reversible counter 6 turn out to be logical zeros.

At the beginning of the fourth phase of the cycle, at the command of the generator 7, the auxiliary input of the descrambler 8 is gated, and in the case of fulfillment of the condition (1), a coincidence pulse arrives in the counter 9 of the coincidence pulses. The counter size 9 determines the number of cycles needed to make a decision about the presence of a ring signal. In this case, the counter 9 protects the receiver from random conversational signals with a frequency close to the reference frequency.

Overflow of counter 9 indicates the presence of a ringing signal at the input, and a device response signal appears at its output.

Detector 4 provides additional protection from conversational signals. If there are conversational signals at the input, then in the pauses between them, the output of the detector 4 connected to the setup input of counter 9 of coincidence pulses is a signal that sets counter 9 to its initial state.

Claims (1)

Invention Formula A selective call receiver with a reference signal, containing an amplifier-limiter, a serially connected counter and a decoder, as well as a clock pulse generator, characterized in that, in order to increase the number of received wake frequencies, it is connected in series with the front-side driver and the switch. connected by a detector and a pulse counter coincidence, the counter is reversible, with the output of the amplifier-limiter connected to the input of the front driver, the output of T Sogo one with a detector input and the first output of the switch - with the input of adding the reverse Editor T. Parfenova. Order 1965/60 Compiled by V. PanishchIs Techred. ITayoshoshka Corrector L. Pilipenko Circulation 624 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 the counter, the input of which is subtracted, is connected to the second output of the switch, the second and third inputs of which are connected to the corresponding outputs of the clock generator, the third output of which is connected to the reset input of the reversible counter, the overflow output of which is connected to the first output of the clock generator, the fourth output of which connected to the auxiliary input of the decoder, the output of which is connected to the input of the pulse counter of coincidence, and the inputs of the decoder to the p-outputs of the higher bits of the reversible counter ka, and the input of the limiting amplifier is the first input of the device, and the fourth input of the switch is the second input of the device.