JPS603231A - Data signal sound attenuating system - Google Patents

Abstract

PURPOSE:To prevent generation of silent state and click noise by transmitting a pre-signal before a data signal transmitted intermittently together with a voice signal and decreasing an output level of a voice circuit during the reception period of the data signal. CONSTITUTION:A voice entering a microphone 1 is converted into a voice signal A at an amplifier 2 at the transmission side and fed to a transmitter via a changeover device 3. A control circuit 10 generates the pre-signal and the data signal B via an FSK modulator and also transmits the signal B to the transmitter by changing over the changeover switch 3. A signal C having the signal B in a part of the signal A is transmitted from an antenna 5 via the transmitter. Then the voice signal received is sounded from an amplifier 45 at the reception side and a speaker 46 via a switch circuit 47. Since a control circuit 40 at the reception side opens the circuit 47 in receiving the pre-signal, the input level of the data signal received after the pre-signal to the amplifier 45 is divided by resistors 43, 44. Thus, the sounding level of the data signal is reduced remarkably in comparison with the voice signal.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is directed to a communication system in which a data signal is intermittently transmitted along with a voice signal on one communication path, such as a personal radio device which has been developed in recent years. This article relates to the data signal sound attenuation method used in the communication method.

[Technical background of the invention]

Conventionally, there is a conventional wireless system in which a predetermined data signal is intermittently superimposed and transmitted in order to identify radio waves transmitted.

Therefore, in this system, after the communication path is formed, the communication operation is performed without any control.

The data signal sound caused by the data signal is intermittently broadcast to the caller from the speaker or the like.

This data signal tone is extremely unpleasant and harsh to the caller. This is because the modulation depth of data signals is generally set to be equal to or higher than the voice level in order to ensure a certain error rate, and as a result, the data signal sound is perceived as quite loud to the caller. Because it opens.

[Problems with background technology]

Therefore, various methods have been devised to eliminate this annoying data beep.

For example, one method is to cut off the communication path.
.

With this method, silence suddenly occurs during a call, which may be strange to the person on the receiving end.

Also, for example, if the audio amplifier's power supply circuit is configured to control the disconnection of the communication path, a clicking sound will be generated when the communication path is connected again, creating another annoying noise. Lick to do it.

[Purpose of the invention]

The present invention has been made by focusing on the above-mentioned points.
It is an object of the present invention to provide a data signal sound attenuation method which can suppress ℃ data from becoming gibberish in a simple configuration and allows comfortable telephone calls.

[Summary of the invention]

Therefore, in the present invention, a prefix signal is sent from the transmitting side so as to be positioned before the data signal, and when the receiving side detects this prefix signal, at least the audio circuit is The above objective was achieved by reducing the output level.

[Embodiments of the invention]

The present invention will be explained below with reference to the drawings.

FIG. 1 is a configuration diagram of an embodiment of a transmitting side device applied to the present invention, where l is a microphone, 2 is a transmitting side amplifier (
It's called TAMP. ), 3 is a switch, 4 is a transmitter, 5 is an antenna, 6 is a modulator at F8, and IO is a transmitting side control circuit. The sending side control circuit 10 connects the signal C to the switch 3xTAMP2 side as a high signal at LJ level when transmitting an audio signal, and switches the signal C as an "H" level when transmitting a prefix signal and a data signal. The device 3 is connected to the FSK modulator 6 side. Next, this sending operation will be explained.

First, when the transmission side control circuit 10 needs to transmit a data signal, it creates a data signal, changes the signal level from "L" level to "H" level, and makes it possible to transmit a take signal. Then, at F8, the modulator 6 inputs the prefix 4 one bit at a time in synchronization with the falling edge of the highly accurate transmission clock b.
The g signal and the take signal are introduced into the FSK modulator 6.

The i'sK modulator 6 sends this input signal a to the FSK switch 3 at the baseband. Therefore, the pre-signal and take-signal are sent via the transmitter 4 and antenna 5. Thereafter, when the transmission of all the take signals is completed, the transmitting side control circuit 1g returns the signal e to the "L" level and transmits the audio signal obtained from the microphone 2 again. Figure 1 shows the signal waveform of the Gokuri device, and Figure 2 shows the signal A.
The output of AMP2, signal -13, is the output of FSK modulator 6, signal V is the tli control signal of switch 3, and signal C is the output of switch 3.

Here, we will simply mention the data signal and the prefix symbol 1 (fj).The format of these signals is as shown in Figure 3, and the data signal is positioned immediately after the prefix signal. It has become.

Further, the prefix signal is formed by a bit synchronization signal and a frame synchronization signal. Therefore, the sender control fls1
01d, always transmit a preset prefix signal before transmitting the data signal.

FIG. 4 is a configuration diagram of an embodiment of a receiving side device applied to the present invention, in which 41 is an antenna, 42 is a receiver, 43.4
4 is a resistor, 45 is a receiving amplifier (referred to as RAMP),
46 is a speaker, 47 is a switch circuit that is closed when the detection signal e is at the rJ level and is open when it is at the rHJ level, and 48 is a circuit for guiding the baseband signal demodulated by the receiver 42. Here, it is assumed that the signal received by the receiving device is the signal transmitted from the above-mentioned transmitting device.

First, the transmitted audio signal is received by the receiver 42 via the antenna 41Y, where the signal is demodulated and then sent to the line 3. The γ demodulated signal sent to the line 3 is sent to the RAMP 4 via a switch circuit 47 consisting of an analog switch such as a relay or a transistor switch.
5 will be introduced. Therefore, the demodulated signal is amplified and then output from the speaker 46.

Incidentally, in this case, the switch circuit 47 is described as being in a closed state, but this point will be described later.

Next, the operation at this time when the prefix signal is detected is shown in Figure 5.
This will be explained with reference to FIG. FIG. 5 is a block diagram of the main parts of the receiving side control circuit 40, and 51 is a signal demodulator for F8.
52 is a bit synchronization circuit, and 53 is a control section. A pre-signal is sent to the antenna 41 instead of the audio signal. When received through the receiver 42, this prefix 48 is converted into an NRZ signal by the FSK signal demodulator 51, and this NRZ signal is introduced into the bit synchronization circuit 52 and the control section 53. The beginning of this prefix signal! 1S is a bit synchronization signal, and based on this signal, the bit synchronization circuit 52 aligns the phases of the bits of the input data signal and the reception clock output from the bit synchronization circuit 52 as shown in the timing chart of FIG. Note that the signal E in FIG. 3 is the reception clock output from the bit synchronization circuit 52, and the signal F is the N-Z signal output from the signal demodulator 51 at F8.

The control unit 53 opens and closes the switch circuit 47 according to the operation flow shown in FIG. 7 based on these signals E and F.

This control section 53 first resets the synchronization flag as an initial setting, and sets the output detection signal eq to LJ level. The data is compared with the data pattern of the frame synchronization signal set in advance.If the comparison results match, the control unit 53 sets the synchronization flag and then sets the detection signal e to the "H" level. Since the circuit 47 is in a closed state, the level of the signal (data signal) input to the RAMP 45 is changed to the level of the resistor 43.4.
4, and the sound level from the speaker 46 is significantly lower than that of the audio signal. by the way,
In a communication system in which the data signal length is set in advance, the control unit 53 measures time using an internal timer or the like, and the control unit 53 measures the time using an internal timer or the like, and outputs the detection signal e Y "HJ level" for a predetermined period after detecting the prefix signal. In a communication system where the length is irregular, the detection signal e may be set at the rHJ level until the data end signal inserted at the end of the data signal is detected.In other words, the control unit 53 may at least keep the detection signal e at the rHJ level during the reception period of the data <= signal. The detection signal is set to eGerHJ level, and the switch circuit 47
It is sufficient if it allows the device to be in an open state.

Therefore, as described above, the level of the unpleasant data signal sound can be lowered, so that discomfort can be alleviated.

FIG. 8 is a configuration diagram of another embodiment of the transmitting side device applied to the present invention, and the same reference numerals are used for the same main parts as in the if diagram, and the explanation thereof will be omitted. 8 is the switch 3 and the FSX modulator 6
A resistor 9 is connected in between, one end of which is grounded and the other end connected to the switch 3, and 7 which is connected in parallel to form a bypass with respect to the resistor 8, forming a switch circuit.

Further, this switch circuit 7 is in an open state when the signal d is at the HJ level [and is in a closed state when it is at the J level.

Next, Figure 9 shows the signal waveforms of each part and the transmitter side.
The transmission operation of this embodiment will be explained with reference to FIG. 10 showing the operation flow chart of the circuit 20.

First, the transmitting side control @l path 20 receives the signals c,
d is set to the "L" level, the switch 3 is connected to the TAMPZ side, and the switch circuit 7 is opened. When the transmission side sub-circuit 20 needs to transmit a data signal, it creates a take signal and changes the signals c and d from the Ill level to the Ill-1j level to enable data signal transmission.

Thereafter, the prefix signal 7 is transmitted one bit at a time in synchronization with the falling edge of the highly accurate transmission clock b obtained from the FSK modulator 6.
The signal is introduced into the FSK modulator 6. The FSX modulator 6 modulates this input signal a 'li F 8 K and sends it to the switch 3, but at this time the switch circuit 7 is in the open state, so the signal is divided by the resistor 8°9 and the level is changed. decreases. Therefore, the previous # signal whose signal level has been suppressed is transmitted via the transmitter 4 and the antenna 5. Next, sender control II! l! When the l path 20 finishes sending out all bits of the OIJ device code, the signal d is set to the rLJ level again and the switch circuit 7
is returned to the open state, and the data 1 signal is introduced into the modulator 6 at F8 one bit at a time. This data signal is FSK
After being modulated, the switch circuit 7 is activated and the data signal is sent to the switch 3, so unlike the pre-signal, the data signal is not level-suppressed (...After that, when all the data signals are sent out, , the transmitting side control circuit 2'0 also sets the signal C to "L".
level and enters the audio signal transmission state.

In this way, only the modulation level of the 'S1 signal is lowered and transmitted, and when this is received by the receiving device shown in Fig. 4, the level of the data signal sound is lowered and the discomfort is alleviated. At the same time, the level of the pre-signal sound can be lowered, so that the discomfort can be further reduced.

FIG. 11 is a block diagram of another embodiment of the transmitter 9111 device applied to the present invention, and FIGS. 1 and 8 are switching devices. In this embodiment, unlike the previous embodiment, a tone signal obtained by the tone signal generation circuit 81 is added to the prefix signal. Further, the modulation degree of this tone signal is set to be lower than the modulation degree of the data signal.

Next, the 121st section showing the operation flow of the send<g side control circuit 30.
The transmission operation of this embodiment will be briefly explained with reference to Kaoru.

First, the transmitting side control circuit 30 receives signals c and d as an initial setting.
is set to rLJ level, and switch 3 is set to TAMP side.
2 is connected to the FSK modulator 6911I. Then, when the transmitting side control circuit 30 needs to transmit a data signal,
Create a data signal and change signals c and d from ITLJ level to rHJ level. When the signal d reaches rHJ level, the switch 82 is connected to the tone signal generation circuit 81, so that the switch 82.3. A tone signal, which is part of the pre-signal, is transmitted via a transmitter 4 and an antenna 5. After transmitting the tone signal for a predetermined period of time using an internal timer or the like, the transmitting side control circuit 30 receives the signal d, sets it to the ILj level, connects the switch 82 to the FSK modulator 6, and starts the transmitting clock b. In synchronization with the downlink, it is sent one bit at a time to another prefix signal and a data signal, 1" 8K modulator 6. Therefore, data 4 is sent to the tone signal, which is a prefix signal.
The third issue is sent out.

In the receiving side device which receives such a type of signal, 55 is a tone detection path. The receiving operation will be explained with reference to FIG. 14 showing the operational flow of the receiving side control circuit 40. When a tone signal, which is the prefix 4M, is transmitted, received via the antenna 41 and receiver 42, and detected by the tone detection circuit 55, the tone detection circuit 5
5 outputs a tone detection signal q. The control unit 53 is
When this tone detection signal G is detected, the detection signal eYrHJ
level. After that, when a frame synchronization signal is received, a synchronization flag is set, and the data signal to be inputted thereafter is received. At this time, if the frame synchronization signal is not detected even after a predetermined period of time has elapsed since the tone detection signal G was output, the control unit 53 forcibly sets the detection signal e to the "L" level and enters the audio signal reception state. By recursing in this way, it is possible to lower the level of the i= sound for some of the prefix signals such as data No. 43 and frame synchronization No. 4W, and the level of No. 4g, whose level is not lowered, becomes a tone that is not harsh on the ears. Since it is a signal, discomfort can be further reduced. Incidentally, if the tone signal is a tone multi-frequency signal, malfunctions caused by voice can also be reduced. Furthermore, in all of the embodiments described above, the signal level is lowered by voltage division using resistors, but the present invention is not limited to this; for example, the signal level may be lowered by changing the gain of the amplifier.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to suppress the ringing sound with a simple configuration, and it is possible to make a comfortable call. Also, since there is no disconnection of one communication path,
It is possible to prevent the clicking sound when the communication line is disconnected, and also eliminates the feeling of strangeness in the silent state.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of a transmitting device applied to the present invention, FIG. 2 is a signal waveform diagram of each part thereof, and FIG. 3 is a prefix signal and data signal sent from this transmitting device. Figure 4 is a diagram showing the configuration of an embodiment of the receiving side device applied to the present invention, Figure 5 is a configuration diagram of its main parts, and Figure 6 is a signal waveform diagram of its main parts. , FIG. 7 is an explanatory diagram of its operation, FIG. 8 is a configuration diagram of another embodiment of the transmitting side device applicable to the present invention, FIG. 9 is a signal waveform diagram of each part thereof, and FIG.
The figure is an explanatory diagram of its operation, FIG. 11 is a configuration diagram of still another embodiment of the sending side device applied to the present invention, FIG. 12 is an explanatory diagram of its operation, and FIG. FIG. 14 is a diagram illustrating the main part of another embodiment of the receiving device, and FIG. 14 is an explanatory diagram of its operation. 3...Switcher, 6...FSK modulator, 7...
・Switch circuit, 8.9...Resistance, lO・20...
・φ sending side control circuit, 40...receiving side control circuit i, 4
3.44...Resistance, 47...Switch circuit, 5
1...F8 is a signal demodulator, 52...Bit synchronization circuit, 53 is a patent attorney Norichika Kensuke (and 1 other person)
Figure 3 Concave Figure δ Figure 9 C-eup's Isshin Ichiyanagi-nabe Saving Silence

Claims (4)

[Claims] (1) In a communication system in which a data signal is intermittently transmitted along with an audio signal on a communication channel, the transmitting side transmits a device signal for a predetermined period of time before transmitting the data signal, and the receiving side transmits a device signal for a predetermined period of time before transmitting the data signal. When the prefix 1 is detected,
3. A data signal sound attenuation method characterized in that the output level of an audio circuit is reduced at least during the reception period of the data signal received after the data signal is received. (2) The data signal sound attenuation method according to claim (1), characterized in that the modulation degree of the preceding item 16 is lower than the modulation degree of the data signal. (3) At least a part of the prefix signal is a tone signal and is characterized by red bean paste.Claims (1) or (2)
Data signal sound attenuation method described in Section 2. (4) The data signal sound attenuation method according to claim (3), characterized in that the multi-frequency signal is a tone signal having a -syr configuration with a small number of pre-signals.