JPS62274842A - Radio communication equipment - Google Patents

Abstract

PURPOSE:To attain mutual simultaneous talking between a master station and plural slave stations without hindrance such as crosstalk in each one channel of transmission/ reception radio channel by using the same frequency for the master station and the plural slave stations and controlling the frequency sequentially at a high speed with a synchronizing signal from the master station. CONSTITUTION:An optional station is used as the master station A and others are used as slave stations B, the transmission frequency of the master station A and the reception frequency of the plural slave stations B are assigned to the same radio channel, the transmission frequency of the slave stations B and the reception frequency of the master station are assigned to one and same radio channel having the different frequency from the above frequency, a synchronizing signal is superimposed onto the sending signal from the master station A at all times, the sending period of each station is set in advance so as not to be overlapped with that of other station in the slave stations B, the sending period of its own station is controlled automatically by using the synchronizing signal and the stations are operated sequentially according to the set sending period. Thus, the simultaneous mutual talking between the master station and the plural slave stations B is attained without crosstalk by using the radio channel for each transmission/reception.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a wireless communication device, and particularly to a wireless communication device suitable for simultaneous mutual communication between a large number of people.

[Conventional technology]

Traditionally, wireless communication devices that allow multiple people to talk to each other at the same time are
As discussed in "Electronic Communication Handbook" edited by the Institute of Electronics and Communication Engineers, published by Ohmsha, 1979, pages 1107 to 1115, the simplex system.

There were multiple systems and semi-duplex systems. In the simplex system, one radio channel is required for one call line, and in the duplex and semi-duplex systems, two radio channels are required, and for multiple people to talk to each other at the same time, call lines for each person are required. becomes.

[Problem that the invention attempts to solve]

In the conventional example described above, it is necessary to allocate radio frequencies for multiple channels in order for multiple people to communicate with each other at the same time. especially,
With wireless communication devices that use weak radio waves, the communication range is usually about 100 meters, and if you make a call within this range, you will be operating the wireless devices at close range, so reception due to cross modulation may occur. This has caused problems such as reduced sensitivity, adjacent channel interference, and intermodulation, which can impede wireless communication.

Furthermore, one or two radio channels are required for each communication line, and consideration must be given to the radio channel plan to avoid interference from spurious radiation waves. For example 400~
In the 420 MHz band, there are approximately 25 wireless channels, and even if there is no interference mentioned above, the maximum number of lines that can be used simultaneously is 25 lines (single call system), which requires dozens of people to talk to each other at the same time. In some cases, there were problems that could not be addressed.

- An object of the present invention is to provide a wireless communication device that allows simultaneous communication between a master station and a plurality of slave stations using one wireless channel for transmission and one reception, without problems such as interference.

[Means for solving problems]

The above purpose is to set any one of the multiple radio stations as a master station and the others as slave stations, to assign the transmission frequency of the master station and the reception frequencies of multiple slave stations to the same radio channel, and to The transmission frequency of the station and the reception frequency of the master station are assigned to the same radio channel channel with a frequency different from the above, and a periodic signal is always superimposed on the transmission signal of the master station. This is achieved by setting the transmission timing in advance so as not to overlap with that of other stations, automatically controlling the transmission timing of the own station using the synchronization signal, and sequentially operating the transmission timing according to the set transmission timing.

[Effect]

Since the transmission frequency of the master station and the reception frequency of the plurality of slave stations are the same, the voice of the master station can be received by the plurality of slave stations. Since the transmission frequency of multiple slave stations is the same as the reception frequency of the master station,
The audio from the slave station can be received by the master station. Here, since there are multiple slave stations and their transmission frequencies are the same, interference will occur if they transmit at the same time.6 Therefore, in order to avoid interference, the transmission times of the two types of slave stations are set in advance so that they do not overlap with each other, and the Control is performed sequentially at high speed using synchronization signals from the station.

As a result, a plurality of slave stations will not be in a transmitting state at the same time, so simultaneous mutual communication between a master station and a plurality of slave stations can be realized without interference using one radio channel for each transmission and reception. Further, by mixing the voice of the slave station received by the master station with the voice of the master station and transmitting the mixture (operating as a so-called repeater), it is possible to make simultaneous calls between multiple slave stations.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a master station and a slave station of the present invention. FIG. 1(A) is a block diagram showing the configuration of the master station of the present invention, and numeral 1 indicates a control section which is the main device of the present invention. The control unit 1 includes a synchronizing signal generator 29, a frequency divider 4. AN
D circuit 3. Bypass filter (hereinafter referred to as HPF) 8.
It consists of a mixer 7. In addition, microphone 6, speaker 5
．． Wireless transmitter9. Wireless receiver 10. The antenna 11 is the same as the conventional master station. FIG. 1(B) is a block diagram showing the configuration of the slave station of the present invention, and 20 is a main carrier control section which is the main device of the present invention.

The main carrier control unit 20 includes a bandpass filter (hereinafter referred to as B
PF>24. HPF25. Reset pulse generator 22. Counter 21. The decoder consists of a 26° diode switch 29. Note that the microphone 279 and the frequency modulator 28. Wireless transmitter 30° wireless receiver 31. Speaker 23. The antenna 32 is the same as the conventional slave station component equipment.

The operation of the apparatus of the present invention will be explained below. For convenience of explanation, it is assumed here that the master station and four slave stations communicate with each other simultaneously using one wireless channel for each transmission and reception.

The synchronizing signal generator 2 shown in FIG. 1(A) includes NAND gates ICI and IC2 shown in FIG. 2, and resistors R1 to R4.
, a crystal oscillator X1.

Here, the NAND gates ICI and IC2 are, for example, 5N74
Use 00. The synchronization signal generator 2 includes a crystal oscillator x1
A pulse corresponding to the natural frequency of is output to line A4. As shown in FIG. 4(1), the pulse waveform of line A4 is an on-off repeated pulse with a pulse width and a pulse interval of T 1 ms, and its frequency is, for example, 10 KHz. One of the outputs of the synchronization signal generator 2 is sent to an AND circuit 3,
The other end is connected to frequency divider 4. The A, ND circuit 3 is an AND gate IC 5, for example, 5N7, as shown in FIG.
408. Similarly, the branching device 4 is, for example, 5N7
A quinary counter IC3 consisting of 490 and eg SN74
This is a monostable multivibrator IC4 consisting of 123. As shown in FIG. 4(2), the output A1 of the counter IC3 is outputted at a rate of one for every five output pulses (FIG. 4(1)) from the synchronizing signal generator. This output is converted into the waveform shown in the fourth [il (3)] by the monostable multivibrator IC4. Here, the pulse width Tδ is the time for four output pulses of the synchronization signal generator 2, and is set by the capacitor 01 and the resistor R5. The output A2 of the monostable multivibrator IC4 is input to the AND gate IC5, and the output A3 of the AND gate IC5 is as shown in Fig. 4 (4).
The waveform shown is obtained. That is, when the output of the monostable multivibrator IC4 is on, pulses P1 to P4 synchronized with the output pulses of the synchronization signal generator 2 are repeatedly output. These repeatedly generated pulses P1 to P4 are shown in Figure 1 (
It is input to the mixer 7 shown in A). The mixer 7 consists of an operational amplifier IC6 as shown in FIG.
In addition to the output pulse of C5 being input through resistor R6, the output A4, which is the sound from microphone 6 adjusted to a predetermined signal level by an amplifier consisting of resistors R12, R13 and operational amplifier IC9, is input through resistor R8. is input. Also, H
The signal of P F 8 is also input, but for the sake of explanation, it will be described here along with the operation of the slave station. In this way, the mixer 7 mixes the sound from the microphone 6 with the sound from the microphone 6 (see Figure 4).
) is mixed with the synchronizing signal which is the output A3 of the AND gate IC5 shown in FIG.
For example, antenna 1 is used as an FM radio wave (400 MHz).
It is radiated from 1. The structure of the wireless transmitter 9 is the same as that of the conventional device, so a detailed explanation will be omitted here.

An FM radio wave radiated from the antenna 1 is received by the radio receiver 31 from the antenna 32 of the slave station shown in FIG. 1(B), and output as a low frequency signal after FM detection. Since the wireless receiver 31 is equivalent to a conventional device, a detailed explanation of its operation will be omitted. Since the output of the wireless receiver 31 is a mixture of the audio signal and the synchronization signal, the audio signal is separated by the BPF 24.
The synchronization signal is separated by HPF25. The BPF24 includes an operational amplifier ICl0 and resistors R21 to R2 as shown in FIG.
5 and capacitors CIO to C12. Since the audio frequency band is usually about 0.5 KHz to 3 KHz, the low cut frequency is set to 0.5 KHz by the combination of resistor R22 and capacitor C11.
The combination of resistor 23 and capacitor 10 makes the high cut frequency 3KHz. Sound is output from the speaker 23 via the capacitor C12. In this way the first
The audio input from the microphone 6 of the master station shown in FIG. 3A can be heard through the speaker 23 shown in FIG.

On the other hand, the synchronization signal is generated by the HPF 25, which consists of the operational amplifier C11 shown in FIG.
separated and formatted. The low cut frequency of operational amplifier ICI 1 is determined by resistors R26, R27 and capacitor C13,
Set in C14. Here the synchronization signal is 10KH
z, the low cut frequency is set to 8KHz. The output of the operational amplifier C11 is shaped by a Schmitt inverter IC12 and output as a rectangular wave pulse train shown in FIG. 4(4). This output is input to the reset pulse generator 22 and counter 21, respectively. The reset pulse generator 22 is composed of a retrigger type stable multivibrator ICl3 (for example, SN74123), and outputs a signal for resetting the counter 21. The reset timing is at the falling edge (when changing from on to off) as shown in Figure 4 (4)
As shown in FIG. 4 (5), the reset pulse is on while the synchronization pulses P1 to P4 are being input, and after the synchronization pulse P4 is turned off, the reset pulse is turned off.

The on/off timing of the reset pulse shown in FIG. 4(5) is set by the resistor RIO and capacitor C9 of the retrigger type monostable multivibrator ICl3 shown in FIG. The counter 21 is, for example, a binary coded 0-base counter IC 14 using 5N7490A. , the binary coded decimal counter IC14 receives the first synchronization signal from the Schmidt inverter C12 as shown in FIG.
Output terminal A is turned on, when the second input is input, output terminal A is turned off and output terminal B is turned on, when the third input is input, output terminals A and B are turned on, and when the fourth input is input, output terminal A is turned on. , B are turned off and the output terminal C is turned on. Furthermore, when a reset pulse is input, output terminals A to D are turned off. These output signals are input to a binary coded decimal-decimal decoder IC15 (for example, 5N7442A). 2
Evolution 1 o base-decimal decoder I (,15, binary evolution 1
A decimal output (output terminals 0 to 9) corresponding to the input power is obtained.

Since this output is off when the binary coded 10 input is on, it is inverted via the inverter IC16 (for example, 5N7404). Among the four slave stations, slave station A is a binary coded decimal-decimal decoder IC.
It is connected to the output terminal (1) of l3, and similarly connected to (4) at the fourth slave station. Therefore, the output A5 of the inverter IC 16 of each branch office is turned on at the timings shown in FIG. 4 (6) to (9). Here, the sound from the microphone 27 is modulated by a frequency modulator 28, for example, 34
It is output as an FM signal of MHz±ΔF.

Since the frequency modulator 28 is equivalent to the conventional device, a detailed explanation of its operation will be omitted. The above FM signal is capacitor C14
~016. Diode switch 29 consisting of diode D1 and coil L1. Wireless transmitter 30. It is radiated via the antenna 32 as an FM radio wave with a frequency f2 (for example, 408 M, Hz).

The frequency f2 is here the output 34 M of the frequency modulator 28
The explanation is given as 408M, Hz, which is 12 times Hz, and the 12 times multiplication is performed by the wireless transmitter 30.

Since the wireless transmitter 30 is the same as the conventional one, a detailed explanation of its operation will be omitted. The diode switch 29 is turned on and off by the output of the inverter IC 16 as shown in FIG. In other words, when the output of the inverter IC16 is on, the diode D1 is on, and the output from the frequency modulator 28 is input to the radio transmitter 30 via the capacitors C14, C15 and the diode D1, and transmits an FM radio wave of frequency f2 to the antenna. 32. Inverter IC
When the output of the antenna 16 is off, the diode D1 is off and the input to the wireless transmitter 30 is cut off, so that no radio waves are transmitted from the antenna 32. Therefore, the timing of transmitting radio waves from the antenna 32 is the same as the on-timing of the inverter IC 16, and as shown in FIG. 4 (6) to (9), each of the four slave stations (slave stations A-B) It will be out of alignment. Therefore, the child MA-Ds do not transmit radio waves at the same time.

The radio waves sent out from the antenna 32 are received by the radio receiver 10 via the antenna 11 shown in FIG. 2, where they are demodulated to become an audio signal. The audio signal is processed by operational amplifier IC7,
I consisting of resistors RIO, R11 and capacitor C2
-r After removing unnecessary signals with P F 8, operational amplifier IC
8, resistors R14 and R15, and a capacitor C3, the signal is amplified to a predetermined level and output as audio from the speaker 5. Therefore, the sound from the microphone 27 shown in FIG. 3 can be heard through the speaker 5 shown in FIG. 2.

In the above-described operation, the master station and the four slave stations can talk to each other simultaneously, but the slave stations cannot talk to each other. For this reason, by inputting the audio output of the operational amplifier IC7 shown in FIG. There is. As a result, the wireless transmitter 9 operates as a so-called repeater, and the master station, four slave stations, and the four slave stations can communicate with each other simultaneously.

In the above explanation, the operation was limited to the master station and four slave stations. By lengthening the ON time of the reset pulse shown in FIG. 4 (5), slave stations can be easily added.

By the way, if the audio output of the HPF 8 of one master station is connected to the mixer 7 of another master station, simultaneous conversation can be made between the slave stations under the control of each master station.

〔Effect of the invention〕

According to the present invention, a simple additional device is attached to a master station and a plurality of slave stations, and simultaneous mutual communication between the master station and a plurality of slave stations can be realized without interference using one radio channel for each transmission and reception.

In addition, the voices of multiple slave stations received by the master station can be mixed with the voice of the master station and retransmitted (operating as a repeater), and simultaneous calls between multiple slave stations can be made, making effective use of radio waves. . Therefore, there is no need for complicated frequency allocation to prevent interference, and simultaneous communication between a plurality of radio stations is possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a wireless communication device according to the present invention, FIG. 2 is a diagram showing an example of the circuit configuration of a master station according to the present invention, and FIG. 3 is a diagram showing an example of the circuit configuration of a slave station according to the present invention. FIG. 4, which is a diagram showing an example, is a diagram showing the timing of various signals. ”, ... control unit of the master station, 2 ... synchronization signal generator, 3.
... A, N D circuit, 4 ... Frequency divider, 5 ... Speaker, 6 ... Microphone, 7 ... Mixer, 8 ...
- Bypass filter, 9... Wireless transmitter, 10...
Radio receiver, 11... Antenna, 20... Main carrier wave control unit, 21... Counter, 22... Reset 1 to pulse generator, 23... Speaker, 24... Band pass filter, 25... Bypass filter, 26...
Decoder, 27...Microphone, 28...Frequency modulator, 29...Diode switch, 30...Radio transmitter, 31...Radio receiver, 32...Antenna.

Claims (1)

[Claims] 1. A master station that includes a control unit that superimposes a synchronization signal on an audio signal, and a main carrier control that separates the synchronization signal and determines the transmission timing of each own station based on the synchronization signal. A wireless communication device for simultaneous mutual communication consisting of a plurality of slave stations equipped with a remote control unit. 2. In the wireless communication device according to claim 1, the control unit of the master station includes a circuit for separating audio signals transmitted from the plurality of slave stations and input of the audio signals by the master station itself. A wireless communication device comprising: a mixer for superimposing the audio signal and the synchronization signal. 3. In the wireless communication device according to claim 2, the mixer receives audio signals from a plurality of slave stations under the control of the other master station, which are received by and separated from the other master station. A wireless communication device characterized by comprising a terminal for inputting.