JPH08274742A - Time-division multiplex transmission system - Google Patents

Abstract

PURPOSE: To transmit a speech signal without including noise components in the speech signal by using the same transmission for sending control signal. CONSTITUTION: The signal processing parts 13 of a master set 1 outputs the control signal for controlling a terminal equipment to a speech superposition control part 15 and outputs the delayed control signal, generated by delaying the control signal by a specific time, to a modulation part 16. Further, the speech superposition control part 15 generates and outputs speech superposition control signal to the modulation part 16. Speech superposition control signal pulses rise a time, longer than the delay time and shorter than a next change point, at a change point of the control signal pulses, and falls at the next change point. The modulation part 16 modulates the speech signal from a speech input part 14 and superposes it on the delayed control signal only when the speech superposition control signal pulse is high. Thus, the speech signal can be transmitted without including a noise component due to the influence of higher harmonic components in the speech signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time division multiplex transmission system for performing signal transmission by time division multiplex between a master and a plurality of terminals or between a plurality of terminals via a transmission line. .

[0002]

2. Description of the Related Art FIG. 7 is an overall configuration diagram of a time division multiplex transmission system according to a conventional example. Five terminal units 2a to 2e are connected to the base unit 1 via a transmission line L, and a predetermined address is set for each of them.

FIG. 8 is a block diagram of a base unit 1 according to a conventional example. The main | base station 1 has the transmission / reception part 11, the demodulation part 12, the signal processing part 13, the audio | voice input part 14, and the modulation | alteration part 16. Here, the transmission / reception unit 11 transmits the transmission signal input from the modulation unit 16 via the transmission line L to the terminals 2a to 2a.
In addition to transmitting to e, the transmission signal transmitted from the terminals 2a to 2e is received via the transmission line L. The demodulation unit 12 demodulates and extracts the voice signal included in the transmission signal input from the transmission / reception unit 11, outputs the voice signal as voice, and outputs the input transmission signal to the signal processing unit 13. . The signal processing unit 13 generates a control signal for controlling the terminals 2a to 2e and generates the control signal.
6 is output. The voice input unit 14 outputs the voice of a person or the like to the modulator 16 as a voice signal. The modulation unit 16 modulates and superimposes the voice signal input from the voice input unit 14 on the control signal input from the signal processing unit 13, and further includes the address data of the terminals 2a to 2e to transmit the transmission signal. Is output to the transmission / reception unit 11.

FIG. 9 is a block diagram of terminals 2a to 2e according to a conventional example. The terminals 2a to 2e include the transmission / reception unit 21.
The address recognition unit 22, the demodulation unit 23, the signal processing unit 24, the voice input unit 25, and the modulation unit 27. Here, the transmission / reception unit 21 transmits the transmission signal input from the modulation unit 27 to the master device 1 and the other terminal devices 2a to 2e, and also transmits from the master device 1 and the other terminal devices 2a to 2e. It receives the transmitted signal. The address storage unit 22 extracts address data included in the transmission signal received by the transmission / reception unit 21, and recognizes whether or not the transmission signal is transmitted to itself. The demodulation unit 23 demodulates and extracts a voice signal included in the transmission signal input from the address storage unit 22 and outputs the voice signal as a voice, and at the same time, the input transmission signal is processed by the signal processing unit 2
4 is output. The signal processing unit 24 controls itself based on the control signal in the transmission signal and generates a control signal for controlling the other terminals 2a to 2e and outputs the control signal to the modulation unit 27. The voice input unit 25 outputs the voice of a person or the like as a voice signal to the modulator 27. The modulation unit 27 modulates and superimposes the voice signal input from the voice input unit 25 on the control signal input from the signal processing unit 24, and includes the address data of the terminals 2a to 2e to be transmitted / received as a transmission signal. It is output to the unit 21.

In the time division multiplex transmission system shown in the above-mentioned conventional example, the modulators 16 and 27 are used when making a call.
In, in the control signals input from the signal processing units 13 and 24, the voice signals input from the voice input units 14 and 25 are modulated and superimposed, and address data is included as transmission signals from the transmission / reception units 11 and 21. The transmission signals transmitted to the base unit 1 or the terminals 2a to 2e via the transmission line L and received by the transmission / reception units 11 and 21 are demodulated in the demodulation units 12 and 23 to extract voice signals and output as voice. It had been.

[0006]

However, in the time division multiplex transmission system having the above configuration, the modulator 1
6 and 27, when the audio signal is modulated and superimposed on the control signal, the audio signal is superimposed in the vicinity of the change point of the control signal, and the noise component is added to the audio signal due to the influence of the harmonic component of the change point. There was a problem that it included a lot of.

Further, transmitting only the voice signal using another transmission line has a problem that the construction is complicated and the cost is increased.

The present invention has been made in view of the above points, and it is an object of the present invention to use a transmission line that is the same as the transmission line for transmitting a control signal to increase the noise component in the audio signal. An object of the present invention is to provide a time division multiplex transmission system capable of transmitting a voice signal without including it.

[0009]

According to the first aspect of the present invention,
The master unit and a plurality of terminals having a unique address are connected via a transmission line, and the master unit inputs a voice as a voice signal by inputting a signal processing unit that generates a control signal for controlling the terminal unit. A voice input unit for outputting, a modulator for modulating the voice signal input from the voice input unit and superimposing the control signal input from the signal processing unit, and including a predetermined address, and outputting as a transmission signal. A transmitting / receiving unit that transmits the transmission signal input from the modulating unit to the terminal unit and receives the transmitting signal transmitted from the terminal unit, and a transmitting signal from the terminal unit that is received by the transmitting / receiving unit. And a demodulation unit for demodulating and extracting a voice signal and outputting a voice,
The terminal device includes a signal processing unit that controls itself based on a control signal, a voice input unit that inputs voice and outputs the voice signal, and a signal processing that modulates the voice signal input from the voice input unit. And a modulator that superimposes the control signal input from the unit and outputs as a transmission signal, and a transmitter / receiver that transmits the transmission signal input from the modulator to the master unit and that receives the transmission signal transmitted from the master unit. An address recognition unit that extracts an address included in the transmission signal and recognizes whether it is a signal for itself, and demodulates a voice signal in the transmission signal from the base unit received by the transmission and reception unit. In a time division multiplex transmission system configured to perform transmission and reception of control signals and voice signals between the master unit and a plurality of terminal devices. Machine and edge A voice superimposing control unit for generating a voice superimposing control signal for designating a superimposing position of the voice signal on the control signal, the modulating unit adding the voice signal based on the voice superimposing control signal. Is modulated to be superimposed on the control signal.

According to a second aspect of the present invention, in the time division multiplex transmission system according to the first aspect, the signal processing section transmits a control signal to the voice superimposition control section, and at the same time, to the modulation section. A delay control signal obtained by delaying the control signal by a predetermined delay time is transmitted, and the voice superimposing control unit causes the pulse of the voice superimposing control signal to be longer than the delay time from the change point of the pulse of the control signal, and , Rising after a time shorter than the next change point of the control signal, falling at the next change point of the control signal, in the modulator, only when the pulse of the audio superposition control signal is a high pulse, The audio signal is modulated and superimposed on the delay control signal.

According to a third aspect of the present invention, in the time division multiplex transmission system according to the first aspect, the transmission signal is composed of two control signal bands and a voice signal transmission band. In the modulation section, the audio signal input from the audio input section is modulated and superimposed on the audio signal transmission band.

According to a fourth aspect of the present invention, in the time division multiplex transmission system according to the first aspect, the voice superimposing control signal is modulated by the modulating section only when the polarity of the control signal is one. It is characterized in that it is output as a transmission signal.

According to a fifth aspect of the present invention, in the time division multiplex transmission system according to the first to fourth aspects, the signal processing unit also generates a control signal for controlling another terminal, It is characterized in that control signals and voice signals are transmitted and received between a plurality of terminals.

According to a sixth aspect of the present invention, in the time division multiplex transmission system according to the fifth aspect, the modulation unit and the demodulation unit of the terminal device are set in advance so that they cannot be modulated and demodulated, and a telephone call is desired. The signal processing unit of the terminal device generates a request signal for requesting a call and transmits the request signal to the master unit, and the master unit performs the call based on the content of the received request signal. The control signal for operating the modulator and demodulator of the device is transmitted.

According to a seventh aspect of the present invention, in the time division multiplex transmission system according to the fifth or sixth aspect, the modulation section and the demodulation section of the terminal unit have characteristics of modulation and demodulation for each terminal unit that makes a call. It is characterized by having to assign.

[0016]

According to a first aspect of the present invention, a voice superimposing control unit for generating a voice superimposing control signal on the control signal is added to the master unit and the terminal unit, and the modulating unit adds the voice superimposing control signal. The audio signal is modulated based on the above to specify the position to be superimposed on the control signal, and the noise component due to superimposing the audio signal in the vicinity of the change point of the control signal is not included in the audio signal. Can be

According to a second aspect of the present invention, in the time division multiplex transmission system according to the first aspect, the signal processing unit transmits a control signal to the voice superimposition control unit, and also to the modulation unit. A delay control signal obtained by delaying the control signal by a predetermined delay time is transmitted, and the voice superimposing control unit causes the pulse of the voice superimposing control signal to be longer than the delay time from the change point of the pulse of the control signal, and , Rising after a time shorter than the next change point of the control signal, falling at the next change point of the control signal, in the modulator, only when the pulse of the audio superposition control signal is a high pulse, The audio signal is modulated and superimposed on the delay control signal, and a noise component is included in the audio signal by superimposing the audio signal on a portion excluding the vicinity of the change point of the delay control signal. It can be so no.

According to a third aspect of the present invention, in the time division multiplex transmission system according to the first aspect, the transmission signal is composed of two control signal bands and a voice signal transmission band, and by the voice superimposition control signal, In the modulator, the voice signal input from the voice input unit is modulated and superimposed on the voice signal transmission band, so that the voice signal can be prevented from containing a noise component.

According to a fourth aspect of the present invention, in the time division multiplex transmission system according to the first aspect, the voice superimposing control signal is modulated by the modulating section only when the polarity of the control signal is one. Then, the signal is output as a transmission signal, and the voice signal can be modulated and transmitted without considering the vicinity of the change point of the control signal.

According to a fifth aspect of the present invention, in the time division multiplex transmission system according to the first to fourth aspects, the signal processing section also generates a control signal for controlling another terminal. Therefore, control signals and voice signals can be transmitted and received between a plurality of terminals.

According to a sixth aspect of the present invention, in the time division multiplex transmission system according to the fifth aspect, the modulation unit and the demodulation unit of the terminal device are set in advance so that they cannot be modulated and demodulated, and a call is to be made. The signal processing unit of the terminal device generates a request signal for requesting a call and transmits the request signal to the master unit, and the master unit performs the call based on the content of the received request signal. A control signal for operating the modulation unit and the demodulation unit of the device is transmitted, and only the modulation unit and the demodulation unit of the terminal device that performs the call are operated, and the communication can be performed between the predetermined terminal devices. .

According to a seventh aspect of the present invention, in the time division multiplex transmission system according to the fifth or sixth aspect, the modulation section and the demodulation section of the terminal unit have characteristics of modulation and demodulation for each terminal unit that performs communication. Is assigned so that it is possible to prevent crosstalk between terminals.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The overall configuration of the time division multiplex transmission system is the same as the configuration shown in FIG. 7 as a conventional example. FIG. 1 is a block diagram showing an example of a master device 1 according to the present embodiment, which includes a transmission / reception unit 11, a demodulation unit 12, and a signal processing unit 13.
The audio input unit 14, the audio superimposition control unit 15, and the modulation unit 16 are included. Here, the transmission / reception unit 11 transmits the transmission signal input from the modulation unit 16 to the terminals 2a to 2e and receives the transmission signal transmitted from the terminals 2a to 2e. The demodulation unit 12 demodulates and extracts the voice signal included in the transmission signal input from the transmission / reception unit 11, outputs the voice signal as voice, and outputs the input transmission signal to the signal processing unit 13. . The signal processing unit 13 generates a control signal for controlling the terminals 2a to 2e and outputs the control signal to the voice superimposing control unit 15, and also a delay control signal obtained by delaying the control signal by a predetermined delay time t is modulated by the modulation unit 16. Is output to. The voice input unit 14 outputs the voice of a person or the like to the modulator 16 as a voice signal. The voice superimposition control unit 15 includes the modulation unit 1.
The delay control signal input to 6 is generated as a voice superimposition control signal for designating the superposition position of the voice signal input from the voice input unit 14, and is output to the modulation unit 16. The modulation unit 16 modulates and superimposes the audio signal input from the audio input unit 14 on the delay control signal input from the signal processing unit 13 based on the audio superposition control signal input from the audio superposition control unit 15. However, the address data of the terminals 2a to 2e is included and output as a transmission signal to the transmission / reception unit 11.

FIG. 2 is a signal waveform diagram showing an example of the control signal, the delay control signal, and the voice superimposing control signal according to the present embodiment. The pulse of the voice superimposing control signal is longer than the delay time t from the change point of the pulse of the control signal and shorter than the next change point of the control signal (in the present embodiment, the delay time t is 2).
It is generated such that it is started after the double time) and then dropped at the next change point. Then, only when the pulse of the voice superimposing control signal is a high pulse, the modulator 16 is set so that the voice signal is modulated and superimposed on the delay control signal. Therefore, as shown in FIG. 3, the voice signal can be superimposed on a portion excluding the vicinity of the change point of the delay control signal, and the noise component due to the harmonic component of the change point of the delay control signal is included in the voice signal. Can be prevented.

FIG. 4 shows the terminals 2a to 2e according to this embodiment.
It is a block diagram showing an example. The terminals 2a to 2e are
Transmission / reception unit 21, address recognition unit 22, and demodulation unit 23
It includes a signal processing unit 24, a voice input unit 25, a voice superimposing control unit 26, and a modulation unit 27. It should be noted that parts that operate in the same manner as those of the blocks of the parent device 1 shown in FIG. 1 are given the same names, and description thereof is omitted here. The address recognition unit 22 is a transmission signal transmitted to itself by extracting address data included in transmission signals input from the transmission / reception unit 21 from the master device 1 and the other terminals 2a to 2e. It is to recognize whether or not. The signal processing unit 24 controls itself based on the control signal in the transmission signals transmitted from the master device 1 and the other terminals 2a to 2e, and also controls the other terminals 2a to 2e. The control signal is generated and output to the audio superimposing control unit 26, and the delay control signal obtained by delaying the control signal by a predetermined delay time t is output to the modulation unit 27.

The operation of this embodiment will be described below.
Note that, here, for convenience of explanation, the main device 1 to the terminal device 2a are referred to.
The communication will be described as an example. The base unit 1 has a voice input unit 1
When the voice is not input to 4, the delay control signal generated by the signal processing unit 13 and delaying the control signal for controlling the terminal 2a is transmitted / received as the transmission signal by including the address data through the modulation unit 16. It is transmitted from the unit 11 to the terminal 2a.

When a voice is input to the voice input unit 14, the voice input unit 14 outputs it as a voice signal to the modulator 16. Then, the modulating unit 16 adds the voice input from the voice input unit 14 to the delay control signal input from the signal processing unit 13 only when the pulse of the voice superimposing control signal input from the voice superimposing control unit 15 is a high pulse. The signal is modulated and superposed, and the address data of the terminal device 2a is included and transmitted as a transmission signal from the transmission / reception unit 11 to the terminal device 2a via the transmission line L.

When the transmission / reception unit 21 of the terminal device 2a receives the transmission signal transmitted from the master device 1, the address recognition unit 22 extracts the address data included in the transmission signal and transmits it to itself. The transmission signal is output to the demodulation unit 23 when the transmission signal is determined to be the transmission signal that has been transmitted and when it is recognized that the transmission signal is for itself. Demodulator 2
The demodulator 3 demodulates and extracts the voice signal superimposed on the input transmission signal, outputs the voice signal as voice, and outputs the transmission signal to the signal processing unit 24. Signal processing unit 24
Controls itself based on the control signal in the transmission signal. When the delay control signal is not input to the modulation unit 16, only the voice signal input from the voice input unit 14 is transmitted as a transmission signal including address data.

Therefore, in the present embodiment, based on the voice superimposing control signal, the modulating unit 16 modulates and superimposes the voice signal on the portion excluding the vicinity of the change point of the delay control signal. The master device 1 or the terminal device 2 does not include many noise components due to the influence of harmonic components in the audio signal.
can be sent to a.

FIG. 5 is a signal waveform diagram showing an example of a transmission signal according to another embodiment of the present invention. In this embodiment, the transmission signal is composed of the control signal band and the voice signal transmission band, and the voice signal input from the voice input units 14 and 25 is modulated and superimposed on the voice signal transmission band. Therefore, it is not necessary to superimpose the voice signal in consideration of the vicinity of the change point of the control signal, and the voice signal can be transmitted to the master device 1 or the terminals 2a to 2e without including many noise components. .

FIG. 6 is a signal waveform diagram showing an example of a transmission signal according to another embodiment of the present invention. In the present embodiment, in the modulators 16 and 27, the signal processors 13 and 24 are included.
The voice signal input from the voice input units 14 and 25 is modulated and transmitted as a transmission signal to the master device 1 or the terminals 2a to 2e only when the polarity of the control signal input from the device is one. Then, the voice signal in the received transmission signal is demodulated and extracted by the demodulation units 12 and 23, and output as voice. Further, the signal processing unit 13 converts the received transmission signal into
A control signal in the transmission signal is extracted by using a low-pass filter or the like, and control is performed based on the control signal.

Therefore, in the present embodiment, it is not necessary to consider modulating the audio signal and superimposing it on the control signal in a portion excluding the vicinity of the change point of the control signal which contains a lot of noise components. The voice signal can be transmitted to the master device 1 or the terminals 2a to 2e without including many components.

In the above embodiment, the terminals 2a-2
Although the demodulation unit 23 and the modulation unit 27 of e are set in advance so that the audio signal can be modulated and demodulated, the present invention is not limited to this, and the demodulation unit 23 and the modulation unit 27 stop operating in advance, that is, the audio signal. Are set so that they cannot be modulated and demodulated, and when a call is to be made in the terminals 2a to 2e, the demodulation section 23 and the modulation section 27 of its own are operated, and the demodulation section 23 of the terminals 2a to 2e to make a call. And a request signal for requesting to operate the modulator 27 to the master device 1, and the master device 1 causes the signal processor 13 to demodulate the demodulators 23 of the terminals 2a to 2e based on the content of the request signal. A control signal for operating the modulator 27 is generated and transmitted from the transmitter / receiver 11. Then, when the terminal devices 2a to 2e that have received the control signal recognize that the address recognition unit 22 is the signal for themselves, the signal processing unit 24 enables the demodulation unit 23 and the modulation unit 27 of their own to enable the predetermined terminals. You may make it talk with the devices 2a-2e.

In the above-described embodiment, a call is made between the pair of terminals 2a to 2e and between the base unit 1 and the terminals 2a to 2e, but it is not limited to this. If there are a large number of terminals 2a to 2e that want to make a call, the demodulation unit 23 and the modulation unit 27 perform the modulation and demodulation so as to have different modulation and demodulation characteristics, so that the communication can be performed without crosstalk. You can

[0035]

According to the first aspect of the invention, the modulator modulates the audio signal based on the audio superposition control signal and superimposes the audio signal on the control signal. By superimposing signals, noise components due to the influence of harmonic components at the change points of control signals can be excluded, and the same transmission line that transmits control signals can be used It was possible to provide a time division multiplex transmission system capable of transmitting a voice signal without including a lot of noise components in the.

According to a second aspect of the present invention, in the time division multiplex transmission system according to the first aspect, the signal processing unit transmits the control signal to the voice superimposing control unit and transmits the control signal to the modulation unit. The delay control signal delayed by a predetermined delay time is transmitted, and the voice superimposition control unit makes the pulse of the voice superposition control signal longer than the delay time from the change point of the pulse of the control signal, and Raise after a time shorter than the change point, and fall at the next change point of the control signal,
In the modulator, the audio signal is modulated and superposed on the delay control signal only when the pulse of the audio superposition control signal is a high pulse. Therefore, the audio signal is added to the part excluding the vicinity of the change point of the delay control signal. It is possible to prevent the noise component from being included in the audio signal by superposing.

According to a third aspect of the present invention, in the time division multiplex transmission system according to the first aspect, the transmission signal is composed of two control signal bands and a voice signal transmission band, and the modulation unit uses the voice superposition control signal. In the above, since the voice signal input from the voice input unit is modulated and superimposed in the voice signal transmission band, it is possible to prevent the voice signal from containing a lot of noise components.

According to a fourth aspect of the present invention, in the time division multiplex transmission system according to the first aspect, the voice superimposition control signal is
Only when the control signal has one polarity, the modulator modulates the audio signal and outputs it as a transmission signal. Therefore, the audio signal is modulated and transmitted without considering the vicinity of the change point of the control signal. be able to.

According to a fifth aspect of the present invention, in the time division multiplex transmission system according to the first to fourth aspects, the signal processing unit also generates a control signal for controlling another terminal device. Therefore, control signals and voice signals can be transmitted and received between a plurality of terminals.

According to a sixth aspect of the present invention, in the time division multiplex transmission system according to the fifth aspect, the modulation unit and the demodulation unit of the terminal are set in advance so that they cannot be modulated and demodulated, and when a call is desired, The signal processing unit of the terminal device generates a request signal for requesting a call and transmits the request signal to the master device, and the master device demodulates and demodulates the terminal device that performs the call based on the content of the received request signal. Since the control signal for operating the unit is transmitted and only the modulation unit and the demodulation unit of the terminal device that performs the call are operated, the call can be performed between the predetermined terminal devices.

According to a seventh aspect of the present invention, in the time division multiplex transmission system according to the fifth or sixth aspect, the modulation section and the demodulation section of the terminal device have characteristics of modulation and demodulation for each terminal device that performs a call. Allotment is made so that it is possible to prevent crosstalk between terminals.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a parent device according to an embodiment of the present invention.

FIG. 2 is a signal waveform diagram showing an example of a control signal, a delay control signal, and an audio superimposed signal according to the present embodiment.

FIG. 3 is a signal waveform diagram showing a transmission signal according to the present embodiment.

FIG. 4 is a block diagram showing an example of a terminal device according to the present embodiment.

FIG. 5 is a signal waveform diagram showing a transmission signal according to another embodiment of the present invention.

FIG. 6 is a signal waveform diagram showing a transmission signal according to another embodiment of the present invention.

FIG. 7 is an overall configuration diagram of a time division multiplex transmission system according to a conventional example.

FIG. 8 is a block diagram of a parent device according to a conventional example.

FIG. 9 is a block diagram of a terminal according to a conventional example.

[Explanation of Codes] 1 Parent unit 11 Transmitter / receiver 12 Demodulator 13 Signal processor 14 Voice input unit 15 Voice superimposition determiner 16 Modulator 2a to 2e Terminal device 21 Transmitter / receiver 22 Address recognizer 23 Demodulator 24 Signal processor 25 Audio input unit 26 Audio superposition determination unit 27 Modulation unit L transmission line

Claims (7)

[Claims] 1. A master unit and a plurality of terminals having a unique address are connected via a transmission line, and the master unit inputs a voice and a signal processing unit for generating a control signal for controlling the terminals. A voice input section for outputting as a voice signal, and a voice signal input from the voice input section is modulated and superimposed on a control signal input from the signal processing section, and a predetermined address is included as a transmission signal. A modulation unit that outputs, a transmission / reception unit that transmits the transmission signal input from the modulation unit to the terminal device, and that receives the transmission signal transmitted from the terminal device,
And a demodulation unit that demodulates and extracts a voice signal in a transmission signal received from the terminal unit by the transmitting and receiving unit and outputs a voice, and the terminal unit controls itself based on the control signal. A signal processing unit for performing, a voice input unit for inputting voice and outputting as a voice signal, a voice signal input from the voice input unit is modulated and superimposed on a control signal input from the signal processing unit, and transmitted. A modulation unit that outputs as a signal, a transmission signal that is input from the modulation unit is transmitted to the master unit, a transmission / reception unit that receives the transmission signal transmitted from the master unit, and an address included in the transmission signal is extracted. Address recognition unit that recognizes whether or not it is a signal to itself,
A demodulation unit that demodulates and extracts a voice signal in a transmission signal from the base unit received by the transmission / reception unit and outputs a voice, and between the base unit and a plurality of terminals. In a time division multiplex transmission system for transmitting and receiving a control signal and a voice signal, a voice superimposing control signal for designating a superimposing position of the voice signal on the control signal is generated in the master unit and the terminal device. A time division multiplex transmission system, wherein a voice superimposing control unit is added, and the modulating unit modulates the voice signal based on the voice superimposing control signal and superimposes the voice signal on the control signal. 2. The signal processing unit transmits a control signal to the voice superimposition control unit, and transmits a delay control signal obtained by delaying the control signal by a predetermined delay time to the modulation unit, The voice superimposition control unit, the pulse of the voice superimposition control signal is longer than the delay time from the change point of the pulse of the control signal, and rises after a time shorter than the next change point of the control signal, It is made to fall at the next change point of the control signal, and in the modulating unit, the voice signal is modulated and superimposed on the delay control signal only when the pulse of the voice superimposing control signal is a high pulse. The time division multiplex transmission system according to claim 1, which is characterized in that. 3. The transmission signal is composed of two parts, a control signal band and a voice signal transmission band, and the voice superimposition control signal is inputted from the voice input part to the voice signal transmission band in the modulator part. 2. The time division multiplex transmission system according to claim 1, wherein the modulated audio signal is modulated and superimposed. 4. The audio superimposing control signal is adapted to modulate the audio signal and output it as a transmission signal in the modulating section only when the polarity of the control signal is one. The described time division multiplex transmission system. 5. The signal processing unit is also configured to generate a control signal for controlling other terminal units, and to transmit and receive control signals and voice signals between a plurality of terminal units. The time division multiplex transmission system according to any one of claims 1 to 4. 6. A request for requesting that the signal processing unit of the terminal device make a call when the modulation unit and the demodulation unit of the terminal device are set in advance so that they cannot be modulated and demodulated, and when a call is desired. Generate a signal and send it to the base unit,
6. The master unit transmits a control signal for operating a modulation unit and a demodulation unit of the terminal device that performs the call based on the content of the received request signal.
The described time division multiplex transmission system. 7. The modulation and demodulation unit of the terminal device is characterized in that modulation and demodulation characteristics are assigned to each of the terminal devices that perform communication.
The described time division multiplex transmission system.