JPS63185242A - Voice duplex communication equipment - Google Patents

Abstract

PURPOSE:To automatically eliminate an inverted crosstalk due to the voice of an opposite talker in use, by deciding the presence/absence of the signals of a low group and a high group, and controlling the switches of a low group side circuit and a high group side circuit in a circuit on a reception side. CONSTITUTION:A control circuit 113 decides the presence/absence of the voice signal of the low group by a reception signal from a distributor 112, and outputs a first control signal for opening/closing a first switch 114, and the switch 114 opens/closes the low group side circuit Lg by the control signal. Similarly, the control circuit 113 decides the presence/absence of the voice signal of the high group by the reception signal, and outputs a second control signal for opening/closing a second switch 115, and the switch 115 opens/closes the high group side circuit Hg by the control signal. In such a way, since it is possible to eliminate the inverted crosstalk due to the voice of the opposite talker using a speech path momentarily and automatically, thereby, satisfactory call can be obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an audio duplex communication system that transmits and receives two different audio signals, and in particular divides one audio band of an audio signal transmission path into a low group and a high group. The present invention relates to an audio duplex communication device that transmits and receives different audio signals of 2° and 2° depending on a low group and a high group.

[Conventional technology]

A conventional voice duplex communication device is configured as shown in FIG. 2, for example. This involves inputting two different audio signals from audio input terminals 201 and 202, and passing them through low-pass filters 203 and 204, respectively.
Extract the low frequency components of the audio band.

The output of the low-pass filter 203 is directly sent to the combiner 207.
and the output of the other low-pass filter 204 is
A modulator 205 modulates the amplitude of the carrier wave with a carrier wave from an oscillator 208, and a bandpass filter 206 extracts only the lower sideband. A combiner 207 combines the output of the low-pass filter 203 and the output of the band-pass filter 206 and outputs the result to an output terminal 208 for transmission.

In this way, two different audio signals are arranged and transmitted in one audio band.

A received signal input from a reception input terminal 210 is split into two by a distributor 211, and one of the branched signals passes through a low-pass filter 212, where only the low group signal is extracted and output to an audio output terminal 216. be done. The other branched signal is passed through a bandpass filter 213 to extract only the high group signal, frequency-converted by a demodulator 214, and returned to the same state as the transmitting side through a low-pass filter 215, and then sent to the audio output terminal. 217.

In this way, using one audio signal transmission path,
It is possible to send and receive two different audio signals.

[Problem that the invention seeks to solve]

Since the conventional voice duplex communication device described above arranges two communication paths within one voice band, a filter with steep attenuation characteristics is required to realize this. However, due to the need to economically construct the device, a certain degree of lack of damping characteristics is tolerated. For this reason, the separation between the two channels is not sufficient, so that, for example, on the receiving side, while listening using one channel, transmission during the channel using the other channel may be interrupted. The speaker on the other side hears what is being said as inverted crosstalk. Particularly, when the person on the other end of the line stops talking on one line, the voice of the other person on the other line becomes reverse crosstalk and hits your ears, making it difficult to have a good conversation. There is.

[Means to solve the problem]

The audio duplex communication circuit of the present invention is an audio duplex communication device that divides one audio band of a transmission path into a low group and a high group, and transmits and receives two different audio signals by the low group and high group. A switch for freely opening and closing the low group and high group circuits on the receiving side of the audio duplex communication device, and a switch for controlling the presence or absence of each of the low group and high group audio signals on the receiving side. The present invention is characterized by comprising a control circuit that monitors and controls opening and closing of the switches according to the status.

[For production]

Therefore, the present invention uses the low group and the high group to automatically remove reverse crosstalk caused by the voice of the other party who is using the device, thereby providing a good conversation.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of one embodiment according to the present invention. Comparing FIG. 1 with FIG. 2 of the conventional example, the difference is that the transmitting circuits Tp and 'r are the same, and only the receiving circuits Rp and R are different. This is the distributor 1 in the receiving circuit R in Figure 1.
12. A control circuit 113 and switches 114 and 115 are provided as shown.

Note that one audio input terminal 101 is connected to a coupler 107 via a low-pass filter 103, and the other audio input terminal 102 is connected to a low-pass filter 104 and a modulator 1.
05. Combiner 107 via bandpass filter 108
The coupler 107 is connected to the transmission output terminal 108.

Further, the reception input terminal 110 is connected to a distributor 111,
The distributor 111 includes a switch 115. Bandpass filter 1
16. Demodulator 117. It is connected to the audio output terminal 121 via a low-pass filter 119, and further connected to the distributor 1.
11 is a distributor 112. Switch 114. It is connected to an audio output terminal 120 via a low-pass filter 118. The carrier wave oscillator 109 is connected to the modulator 105 and the demodulator 117, and the control circuit 113 is connected to the distributor 1.
12 and switches 114 and 115, respectively.

The audio reception signal input to the reception input terminal 110 is supplied by the first distributor 111 to the low group side circuit Lg and the high group side circuit Hg, respectively. Furthermore, the low group side circuit Lg
The received signal is also supplied to the control circuit 113 by the second distributor 112 located at the second distributor 112 .

The control circuit 113 determines the presence or absence of a low group audio signal based on the received signal from the distributor 112, and controls the first switch 114.
The switch 11 outputs a first control signal for opening and closing the switch 11.
4 opens and closes the low group side circuits t and g according to this control signal. Similarly, the control circuit 113 determines the presence or absence of a high group audio signal based on the received signal, and outputs a second control signal for opening and closing the second switch 115, and the switch 115 receives this control signal. to open and close the high group side circuit Hg.

The operation of the control circuit 113 and both switches 114, 115 is determined as shown in the following table.

Table 1 Control status of control circuit and switch V [Effects of the invention] As explained above, the present invention divides the audio band into a low group and a high group, and transmits two different audio signals. A voice duplex communication device that transmits signals, which determines the presence or absence of low group and high group signals in the receiving circuit, and opens and closes the circuits provided in the low group side circuit and the high group side circuit respectively depending on the presence or absence of the signal. By providing a means to control the device, if the other party interrupts the conversation during a conversation using both the high and low groups, the switch is operated accordingly, and the other party who is using the other communication path is interrupted. Since the reverse crosstalk caused by voice is instantly and automatically removed, there is an effect that a good conversation can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure is a block diagram showing a conventional example. 101.102...Audio input terminal, 103.1
04,118,119...Low pass filter,
105...Modulator, 10B, II
EI...Band pass filter, 107...
......Coupler, 108...
・Transmission output terminal, 109......Carrier wave oscillator, 110......Reception input terminal, 111.11:'......Distribution Vessel, 113...
...... Control circuit, 114.115...
...Switch, 117...Demodulator, 120.12
1...Audio output terminal.

Claims (1)

[Scope of Claims] An audio duplex communication device that divides one audio band of a transmission path into a low group and a high group, and transmits and receives two different audio signals by the low group and the high group. A switch for freely opening and closing the low group and high group circuits on the receiving side of the duplex communication device, and monitoring the presence or absence of each of the low group and high group audio signals on the receiving side, A voice duplex communication device comprising: a control circuit that controls opening and closing of the switches depending on the state thereof.