JP2648121B2 - Control signal sound silencer - Google Patents

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 phase shift keying signal is transmitted as an audio signal in advance, the control signal in the audio band unnecessarily sounds a speaker for an audio signal on the receiver side. Used to prevent

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.

In the latter method, although the control signal can be completely prevented from being output to the speaker, the circuit is designed to prevent unnecessary sound from being output from the speaker while detecting the control signal. There is a problem that a delay circuit for an audio signal is required, and a circuit is complicated because a control signal is detected at a high speed and a speaker output is controlled.

[0007]

A control signal sound canceling device according to the present invention is characterized in that when a radio transceiver for switching and transmitting a voice signal or a control signal transmits the control signal, the control signal is transmitted to a voice signal on the receiver side. A control signal sound muffling device for preventing a speaker connected to an output terminal from sounding, receiving the control signal and generating an out-of-band tone signal out of the band of the audio signal in synchronization with the input of the control signal. An out-of-band tone oscillation circuit for inputting to the out-of-band tone transmission input of the wireless transceiver, and converting the control signal into a band frequency of the audio signal and giving a predetermined delay time to the outgoing tone transmission input of the wireless transceiver. An input control signal generating circuit and an output signal from an audio reception output of the wireless transceiver are normally connected to an audio signal output terminal side and a switch control signal is input. A switch circuit for releasing the out-of-band tone signal from the output signal from the out-of-band tone reception output of the wireless transceiver, and outputting the switch control signal. And a control signal detection circuit for extracting and outputting the control signal from the output signal.

[0008]

Next, 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.

On the transmitter side, a control signal 101 such as DTMF or MSK, which is input 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 transmission unit 3 as one of the out-of-band signals. 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; a control signal detection circuit 23 that extracts the control signal 104 from the output signal of the receiving unit 5 and converts it back into a DC pulse signal to output a control signal 108
It is composed of

FIG. 2 is a timing chart of each signal for explaining the operation. That is, on the transmitter side, first, a transmission start signal 102 and a control signal 101 are input upon transmission, the transmitting unit 3 is started, and an out-of-band tone signal 104 and a control signal 103 are provided after a slight delay time. Are sent 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 to the speaker circuit 6 of 04 is completely cut off, and this unnecessary sound is eliminated. Transmission of 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.

Although the above embodiment has been described in connection with a 1: 1 combination of the transmitter side and the receiver side, the present invention can be similarly applied to the case of a 1: N combination as in a parent-child wireless system. .

[0015]

As described above, the control signal tone elimination apparatus of the present invention utilizes the out-of-band signal normally provided in this type of radio transceiver, and eliminates the unnecessary signal generated at the time of transmission of the control signal on the receiving side. Since the sound is deleted, there is an effect that the sound band is narrowed and the sound quality of the sound signal is not degraded, and the circuit scale can be reduced.

[Brief description of the 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)

(57) [Claims] 1. A wireless transceiver for switching and transmitting an audio signal or a control signal to prevent the control signal from sounding a speaker connected to an audio signal output terminal on the receiver side when transmitting the control signal. The control signal is inputted in the control signal sound muffling device, an out-of-band tone signal outside the band of the audio signal is generated in synchronization with the input of the control signal, and is output to the out-of-band tone transmission input of the wireless transceiver. An out-of-band tone oscillation circuit, a control signal generation circuit that converts the control signal into a frequency band of the audio signal, gives a predetermined delay time, and outputs the result to an audio transmission input of the wireless transceiver, and an audio signal of the wireless transceiver. A switch circuit that normally connects the output signal from the reception output to the audio signal output terminal side and opens the switch control signal when it 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.