JPH08251055A - Control signal sound muting device - Google Patents

Abstract

PURPOSE: To prevent a sound signal from decreasing in quality by providing an out-band tone oscillation circuit, a control signal generating circuit, a switch circuit, and an out-band tone detecting circuit, and eliminating an unnecessary sound by utilizing an out-sound-band signal. CONSTITUTION: On a transmitter side, a transmission start signal 103 and a control signal 101 are inputted prior to transmission and a transmission part 3 is actuated to make an out-band tone signal 105 rise and a control signal 104 rise a slight delay time later, thereby sending them to a receiver side. On the receiver side, they are received, a switch circuit 21 is opened with the signal 105 to completely cut off the input of the signal 104, received the slight delay time later, to the speaker circuit 6, thereby eliminating this unnecessary sound. The transmission of the signal 105 is stopped in synchronism with the falling of the signal 104, so the switch circuit 21 is closed on the receiver side at the same time with the completion of the reception of the signal 104 and a sound signal to be sent next is inputted to the speaker circuit 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control signal sound muffling device, and more particularly to a control signal sound muffling device used in a radio transceiver for switching and transmitting a voice signal or a control signal.

[0002]

2. Description of the Related Art A control signal sound canceling device of this type is generally used in combination with a fixed installation type VHF band radio transceiver, and the radio transceiver uses a DTME (Dual tone multi-ereq) for a push button dial.
uency) signal or MSK (Minimum f)
When an in-band control signal such as a case shift keying signal is transmitted in advance as an audio signal, the receiver side unnecessarily sounds the control signal in this audio band at the receiver side. It is used for the purpose of blocking.

Heretofore, this type of control signal sound canceller has divided an audio band into an audio signal and a control signal, and transmitted the signals in different bands so that the control signal does not enter the audio signal. There is something.

As another method, Japanese Patent Application No. 61-03 / 1986
As described in 1921, when transmitting a control signal as a digital signal using subcarriers, a delay is given to the audio signal, the control signal is identified within this delay time, and the audio speaker is turned on. There is something to control not to sound.

[0005]

As described above, the conventional control signal sound muffling device divides the sound band into the band of the sound signal and the control signal in the former method.
There is a problem that the band for the audio signal becomes narrower and the sound quality deteriorates.

Further, in the latter method, although it is possible to completely prevent the control signal from being output to the speaker, the circuit prevents the speaker from outputting an unnecessary sound while the control signal is being detected. There is a problem that a circuit is complicated because a delay circuit for an audio signal is required and a control signal is detected at high speed to control a speaker output.

[0007]

In the control signal sound erasing apparatus of the present invention, when the wireless transceiver for switching and transmitting a voice signal or a control signal transmits the control signal, the control signal is the voice signal on the receiver side. Control signal for preventing a speaker connected to the output terminal from ringing. Inputting the control signal in a muffler and generating an out-of-band tone signal outside the band of the audio signal in synchronization with the input of the control signal. An out-of-band tone oscillating circuit input to the out-of-band tone transmission input of the wireless transceiver, and converting the control signal into a band frequency of the voice signal to give a predetermined delay time to the voice transmission input of the wireless transceiver. The control signal generation circuit to be input and the output signal from the voice reception output of the wireless transceiver are normally connected to the output terminal side of the voice signal, and when the switch control signal is input, A switch circuit that opens the switch, an out-of-band tone detection circuit that extracts the out-of-band tone signal from the output signals from the out-of-band tone reception output of the wireless transceiver, and outputs the switch control signal, and the voice reception output. And a control signal detection circuit for extracting the control signal from the output signal and outputting the control signal.

[0008]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of this embodiment.

At the transmitter side, a control signal 101 such as DTMF, MSK or the like which is inputted prior to the audio signal 102.
Out of band tone oscillating circuit 12 which generates out of band tone signal 105 which rises simultaneously with control signal 101.
The control signal generation circuit 11 converts the control signal 101 into an audio frequency, delays the rise time of a switch circuit on the receiver side, and sends out the control signal 104 to the transmission unit 3.
The control signal sound canceling device (transmitting unit) 1 is constituted by the above. The transmitting unit 3 is activated by the transmission start signal 103 input simultaneously with the control signal 101, and transmits the input control signal 104 or audio signal 102 to the antenna 4. And send it to the receiver side.

The transmitting unit 3 remote-controls the other party's wireless device to the lower side of 0.05 to 0.3 kHz separately from the voice band of 0.3 to 3.0 kHz for transmitting the control signal 104 or the voice signal 102. Out of band tone signal 10
5 is input to the out-of-band signal input circuit of the transmitter 3 as one of the out-of-band signals of the voice. The out-of-band signal input circuit is a portion that is coupled to the audio signal in a state where the audio signal passes through pre-emphasis or the like in the transmission unit 3 and is separated in a band.

On the receiver side, a control signal sound canceling device (receiving unit) 2 for preventing a control signal sound from leaking to a receiving unit 5 for receiving a signal from the transmitter side via an antenna 4 and a speaker circuit 6. It is composed of The control signal sound canceller (reception unit) 2 outputs a switch signal 106 whose logical value changes from 0 to 1 when the transmitter-side out-of-band tone signal 105 is extracted from the out-of-band signal reception output of the reception unit 5. The external tone detection circuit 22 and the switch signal 10
When 6 is 0, the circuit is closed and the switch signal 1
A switch circuit 21 that opens when 06 is 1, and a control signal detection circuit 23 that extracts the control signal 104 from the output signal of the receiving unit 5 and returns it to a DC pulse signal and outputs the control signal 108.
It consists of and.

FIG. 2 is a timing chart of each signal for explaining the operation. That is, on the transmitter side, the transmission activation signal 102 and the control signal 101 are first input for transmission, the transmission unit 3 is activated, the out-of-band tone signal 104 and the control signal 103 with a slight delay time. And rise and are transmitted to the receiver side. On the receiver side, the switch circuit 21 is received by the out-of-band tone signal 104.
Opens, and the control signal 1 received with a slight delay time
The input of 04 to the speaker circuit 6 is completely cut off, and this unnecessary sound is erased. Sending out-of-band tone signal is control signal 1
Since the reception is stopped in synchronization with the fall of the signal 04, the switch circuit is closed at the same time as the reception of the control signal is completed on the receiver side, and the audio signal to be transmitted next is input to the speaker circuit.

The above embodiments have been described for the case of the 1: 1 combination of the transmitter side and the receiver side, but the same can be applied to the case of the 1: N combination as in the parent-child radio system. .

[0015]

As described above, the control signal sound erasing device of the present invention uses the voice out-of-band signal normally provided in this type of wireless transceiver, and does not need to be generated when the control signal is transmitted on the receiving side. Since the sound is erased, there is an effect that the sound band is not narrowed and the sound quality of the sound signal is not deteriorated, and the circuit scale can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a timing chart of signals of respective parts in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 control signal sound canceling device (transmitting unit) 2 control signal sound canceling device (receiving unit) 11 control signal generating circuit 12 out-of-band tone oscillation circuit 3 transmitting unit 5 receiving unit 22 out-of-band tone detecting circuit 23 control signal detecting circuit 21 switch Circuit 4 Antenna 6 Speaker circuit

Claims (1)

[Claims] 1. To prevent the control signal from ringing a speaker connected to an audio signal output terminal on the receiver side when a wireless transceiver for switching and transmitting an audio signal or a control signal transmits the control signal. Of the control signal sound muffler, the control signal is input, an out-of-band tone signal outside the band of the voice signal is generated in synchronization with the input of the control signal, and the out-of-band tone transmission input of the wireless transceiver is output. An out-of-band tone oscillator circuit, a control signal generation circuit for converting the control signal into the frequency band of the audio signal, giving a predetermined delay time and outputting the result to the audio transmission input of the wireless transceiver, and the audio signal of the wireless transceiver. A switch circuit that always connects the output signal from the reception output to the output terminal side of the audio signal and opens it when the switch control signal is input,
An out-of-band tone detection circuit that extracts the out-of-band tone signal from an output signal from an out-of-band tone reception output of the wireless transceiver and outputs the switch control signal; and And a control signal detection circuit for extracting and outputting the control signal sound.