JPH06132848A - Radio communication equipment - Google Patents

Abstract

PURPOSE:To eliminate necessity for a user to adjust the operating threshold value of a VOX circuit again every time peripheral noise is changed by changing the operating threshold value of the detecting operation of the VOX circuit according to an output signal showing the level of a peripheral noise. CONSTITUTION:In the frequency characteristic of a frequency selection circuit 9, a frequency equal to or lower than 200Hz can be detected to detect only the peripheral noise, and a DC output signal 10 is added to a bias signal 8 by an adder circuit 15 and inputted to a threshold value adjusting circuit 14. As a result, when the level of the peripheral noise is changed, the level of the signal 10 is also changed corresponding to it, and the operating threshold value of a VOX circuit 5 is changed as if adjusting an operating threshold value adjuster 6. Since the equipment is operated like this, the operating threshold value of the VOX circuit 5 is automatically changed each time even when noise conditions are fluctuated because a vehicle stops, travels or moves into a tunnel or the like. When any person makes a speak, a transmission circuit 3 is operated and when speaking is stopped, the state of stopping the transmission is kept. Then, the state is made optimum at all times, and it is not necessary for the user to adjust the threshold value again corresponding to the conditions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device used in an automobile, a ship, a train, an aircraft, or in a noisy area in a factory, and relates to both transmission and reception.

[0002]

2. Description of the Related Art In a wireless communication device that performs one-way communication using substantially the same carrier frequency for transmission and reception, a user's voice is transmitted through a microphone, and the other party's voice is transmitted as a sound wave from a speaker or an earphone. In a so-called voice communication device, which has been conventionally known as a transmission / reception switching method, there is a so-called press-to-talk (PTT) switch method in which a manual push button switch is continuously pressed during transmission and a modulation input in a microphone. There is a voice operating transmission (hereinafter referred to as VOX) system that detects the occurrence of an accident and automatically switches. The VOX method is widely used because it is convenient because the transmission / reception switching operation is automatically performed.

Further, even in a radio communication device, such as a portable telephone, which has a carrier frequency for transmission and reception sufficiently separated from each other, can perform transmission and reception at the same time, and does not require switching between transmission and reception. The VOX method is used to detect a silent period in which there is no modulation input and cut off transmission during this period to reduce power consumption of the power supply battery. This invention is such a VO
It relates to the improvement and application of the X circuit.

In recent wireless communication devices, the sending and receiving parts are generally integrated because of the limitation of the installation space.
There are many so-called transceivers. Figure 1
1 shows a typical example of the overall block configuration of such a conventional wireless communication device. In the figure, 1 is a microphone for converting human voice into an electric signal, 4 is an antenna for transmitting and receiving radio waves, 32
Is a speaker that outputs received voice, 40 is a transmission unit that processes a transmission signal, 41 is a reception unit that processes a reception signal, and 16 is a power supply circuit that supplies power to the transmission unit 40 and the reception unit 41. Since the VOX transmission / reception switching circuit described above is generally included in the transmission unit 40 and handled in many cases, here and in the following as well,
Do it that way.

FIG. 12 is a block diagram of a transmission unit 40 and a power supply circuit 16 of a conventional wireless communication apparatus for switching VOX systems, which is similar to that disclosed in Japanese Patent Laid-Open No. 2-52464. Although the receiving unit 41 is also used, the description is omitted for convenience of description. In the figure, 1, 4, 16, 40
Are the same as those in FIG. 2 is an audio signal processing circuit for amplifying the modulated input signal from the microphone 1,
A transmitting circuit 3 oscillates a carrier wave, receives a modulation input signal from the audio signal processing circuit 2, modulates the carrier wave, amplifies the power, and sends the amplified power to the antenna 4.

Reference numeral 5 denotes an input signal detection circuit that receives a modulated input signal from the microphone 1 and detects the presence or absence of the signal, which is also called a VOX circuit, and will be referred to as a VOX circuit in the following description. Reference numeral 6 is an operating threshold adjuster of the VOX circuit 5 composed of a variable resistor, a constant voltage is applied to both ends thereof, and the voltage taken out from the intermediate terminal is fed to a threshold adjusting circuit (described later). It has been entered. Reference numeral 7 denotes a modulated input signal output from the microphone 1, which includes ambient noise as well as human voice. Reference numeral 8 is a bias signal input from the operation threshold adjuster 6 to a threshold adjusting circuit (described later). Reference numeral 14 is a threshold adjustment circuit to which the bias signal 8 is input and which adjusts the operation threshold of the VOX circuit 5. The threshold adjustment circuit 14 forms a part of the VOX circuit 5 in terms of an electronic circuit, and when the VOX circuit 5 is described below, the threshold adjustment circuit 14 is also included in the description. is there.

The power supply circuit 16 is a power supply circuit capable of supplying power to the transmission circuit 3 or stopping supply of power according to the output of the VOX circuit 5 depending on the presence or absence of the modulation input signal 7. Reference numeral 17 denotes a transmission power line supplied from the power supply circuit 16 to the transmission circuit 3. The circuits other than the transmission circuit 3 are always supplied with power.

To explain the operation of the VOX circuit 5, FIG. 13 shows the input / output characteristics of the VOX circuit 5. FIG.
The horizontal axes of (a) and (b) are common and indicate the magnitude of the modulation input signal 7. The lower side (minus side) of the vertical axis of FIG. 13B indicates the magnitude of the bias signal 8. Figure 1
The vertical axis of 3 (b) indicates the sum value (addition value) of the magnitude of the modulation input signal 7 and the bias signal 8. FIG. 13A shows the output level of the VOX circuit 5. When the added value of FIG. 13B is negative, the output is zero, that is, it is judged that there is no modulation input signal 7, and it is positive. When the output is 1, it is determined that the modulated input signal 7 is present. The magnitude of the modulation input signal 7 whose output is inverted from 0 to 1 is called the operation threshold value of the VOX circuit 5. Hereinafter, it may be simply referred to as a threshold. .

The magnitude of the bias signal 8 can be varied widely enough by adjusting the operating threshold adjuster 6, so that the threshold value of FIG. It can be freely set up to the maximum value of. Strictly speaking, various measures have been taken to stabilize the circuit operation, such as the operation threshold having some hysteresis, but since it is not relevant here, the description thereof is omitted.

In order to explain the operation of the radio communication apparatus of FIG. 12 in detail, an example of a so-called transceiver in which a transmitter 40 and a receiver 41 are integrated in FIG.
The external view is shown. 1, 6 and 32 are shown in FIG. 9 and FIG.
Same as 2. Reference numeral 30 denotes a housing of the wireless communication device, in which the circuits shown in FIGS. 11 and 12 are housed. Three
An operation surface 1 is provided on one surface of the housing 30.

Reference numeral 33 is a volume controller for adjusting the output volume of the speaker 32. The operation threshold adjuster 6 for adjusting the operation threshold of the VOX circuit 5 is provided on the surface of the operation surface 31, and has a structure that can be easily adjusted by the user of the wireless communication device. There is. Since this type of transceiver type wireless communication device does not mean that the user is a complete layman, many of these adjustments are made on the assumption that the user will make adjustments in response to changes in the conditions during communication. An operating knob is provided on the operation surface 31.

When ambient noise suddenly increases during use of such a wireless communication device, the user must urgently perform the next operation. That is, (1), (2) VO is transmitted due to noise even though no voice is transmitted.
In order to prevent the X circuit from becoming a transmission state,
Or adjust the VOX circuit so that the other party hears the noise itself when not talking. (3) Make your voice louder so that your voice will not be defeated by surrounding noise. (4) Increase the volume so that the other party's voice from the speaker is not erased by surrounding noise. These problems will be described in detail below.

In order to explain the first problem of such a wireless communication apparatus, FIG. 15 is an explanatory view of the operating state of the VOX circuit. FIG. 15 shows the relationship between the loudness of the input sound to the microphone 1 and the output of the VOX circuit 5 as an example in which the wireless communication device is mounted on an automobile and used. Figure 1
The horizontal axes of 5 (a) to (e) have a common time axis. or,
For convenience of explanation, the time is divided into 0 to t ₉ .
Each time division indicates a time of about several seconds to several tens of seconds. FIG. 15A shows an example of a change in the volume of the transmitted voice (not including ambient noise) to the microphone 1. That _{t 1 ~t 2, t 4 ~t} 5, t 7 ~t 9
In between, it shows that the person is talking to the microphone 1.

FIG. 15B shows an example of changes in the level of ambient noise (not including human voice) around the microphone 1. In other words, time _{0~t 3, t 3 ~t 6,} t 6 ~
shows a case where has changed the ambient noise over t _8, t ₈ ~t ₉ and 4 times. FIG. 15C shows the change in the level of the modulated input signal 7 output from the microphone 1 by combining the sound of FIG. 15A and the ambient noise of FIG. 15B, and also, Two types of high and low operation threshold levels of the VOX circuit 5 necessary for explanation are shown. FIG. 15 (d),
(E) shows the operating state of the VOX circuit 5, and (d) shows VO.
The operation threshold of the X circuit 5 shows a low value shown in FIG. 15C, and FIG. 15E shows a high value.

In FIG. 15, reference numeral 18 denotes the volume level of the voice of the transmitted voice that enters the microphone 1, which will be referred to as a voice level hereinafter. Reference numeral 19 denotes a level of ambient noise that enters the microphone 1, which is hereinafter referred to as a peripheral sound level. Reference numeral 20 denotes a modulation input signal 7 for a sound obtained by adding the sound level 18 and the ambient sound level 19.
Signal level and is hereinafter referred to as the modulation input level. As an example of the operation threshold level of VOX circuit 5, 21 indicates a threshold level set low, and 22 indicates a high threshold level. Here, the VOX circuit 5 is 1 at the same time.
Although it is possible to have only one threshold level, for convenience of explanation, two levels are shown simultaneously on the same figure. 23 is the output of the VOX circuit 5 when the operation threshold level is set to a low threshold level 21, and 24 is the output when the operation threshold level is set to a high threshold level 22,
The output of the VOX circuit 5 is shown.

Next, the operation will be described. Figure 15 (b)
In the figure, from time 0 to t _{3, the} vehicle equipped with the wireless communication device is stopped, and the ambient sound level 19 is relatively low. Further, after time t _3, the vehicle is traveling and the circumferential sound level 19 is high. Also, time t ₆
Between ~t ₈ is due to the vehicle runs, for example, in a tunnel, which shows a case where Shuon level 19 becomes particularly high. After time t ₈ , the vehicle exited the tunnel,
Shuon level 19 down to the same level again time t ₃ ~t ₆ between levels.

Now, the operation threshold value of the VOX circuit 5 is as shown in FIG.
The case where the low threshold level 21 shown in 5 (c) is set will be described. In this case, the output of the VOX circuit 5 is shown at 23 in FIG. 15 (d) as described above. First, from time 0 to t ₁ , the modulation input level 20 is lower than the low threshold level 21, so the output of the VOX circuit 5 is zero as shown at 23 in FIG. At this time, no power is supplied to the transmission power line 17, and the transmission circuit 3 does not transmit. Next, between time t _{1 and} t _2, the modulation level 20 becomes higher than the low threshold level 21 because the voice level 18 is high, and the output 23 of the VOX circuit 5 becomes 1. At this time, power is supplied to the transmission power line 17, and the transmission circuit 3 performs transmission. Between times t _{2 and} t ₃ ,
No transmission is performed as in the case of time 0 to t ₁ . That is, when the ambient sound level 19 is low as shown from time 0 to t ₃ , it is transmitted when the user makes a voice toward the microphone 1, and when the voice is stopped, the transmission is stopped and the reception state is set. The control to say is done normally.

After time t ₃ , the vehicle starts to travel, and as a result, the ambient sound level 19 becomes high, and the modulation input level 20 always exceeds the low threshold level 21 regardless of whether the voice level 18 is high or low. Output of VOX circuit 5
3 always becomes 1 irrespective of the presence or absence of the input voice, and is always in the transmitting state and cannot be received.

With this, normal communication cannot be performed,
Or it does not save power. Therefore, after the time t ₃ , the operation threshold adjuster 6 of FIG. 14 is adjusted to raise the operation threshold level of the VOX circuit 5 to the high threshold level 22 shown in FIG. 15C. explain. In this case, as shown in FIG. 15E during the time t _{3 to} t ₆ , when the audio level 18 becomes high, the output 24 of the VOX circuit 5 becomes 1 and the transmission is performed, and when the audio level 18 becomes low, the output is made. 24 becomes 0, the transmission is stopped, and the operation according to the purpose is performed.

However, even if the high threshold level 22 is set, the vehicle enters the tunnel (wireless communication is possible from inside the tunnel, as will be described later in detail) as shown from time t _{6 to} time t ₈ When the sound level 19 is further increased, the modulation input level 20 always exceeds the high threshold level 22 regardless of whether the voice level 18 is high or low, and the transmission state is always set against the user's will. Expected behavior does not occur.

That is, when the ambient sound level 19 changes according to the running condition of the vehicle or the running environment, the set level of the operation threshold value adjuster 6 shown in FIG. 14 is often changed to change the VOX circuit. The operating threshold of 5 must often be changed accordingly. Although it can be said that the operation threshold adjuster 6 can be easily adjusted as shown in FIG. 14, when the user of the wireless communication device is also driving the vehicle, the operation threshold adjuster 6 cannot be actually operated. Many. In the past, it has been considered that wireless communication cannot be performed in tunnels due to the shielding effect of the ground, but such troubles are noticeable because the number of tunnels that can communicate has increased due to the installation of guide wires. Is becoming.

The second problem of the wireless communication device will be described. The wireless communication device is not limited to one used by a wireless engineer as shown in FIG. 14, and there are wireless communication devices used by an untrained ordinary person. A car phone and a mobile phone are typical ones. An example of the appearance is shown in the external view of the mobile phone in FIG. 16, 1, 4, 31 to 33 are the same as those in FIGS. Reference numeral 34 is a mobile phone housing. Reference numeral 35 is a number push button for inputting the number of the other party of the call, and reference numeral 36 is a hook switch which operates when the housing 34 is housed in a predetermined position and ends the communication.

In the case of a car phone or a mobile phone, the user is often an amateur who has no knowledge of wireless technology. Therefore, it is difficult to adjust the VOX circuit 5 without some technical understanding. The operation threshold value adjuster 6 is not provided on the operation surface 31 or other surfaces.
In the case of such a small device, the operation surface 31 is
Not only the surface on which the number push button 35 is provided, but also all surfaces can be the operation surface.

In the case of the mobile phone shown in FIG. 16 as well, the VOX circuit 5 and the operation threshold adjuster 6 are provided as an internal circuit, and the operation threshold is an appropriate value, for example, when used in a vehicle. It is usually fixed at a relatively high value in consideration of vehicle noise. In some cases, the operation threshold adjuster 6 can be adjusted by using a special tool.
Although there is a structure that can be adjusted from the outer surface of 4, there is a structure that cannot be easily adjusted in any case.

As described above, in the case of the portable telephone, since the transmission and the reception can be performed at the same time, the VOX circuit 5 is not used for switching the transmission / reception, but during the absence of the transmission voice. Is used to stop the power consumption of a power supply battery (not shown). In the case of a mobile phone as well, the VOX circuit 5 may be activated due to an increase in ambient noise as shown in FIG. 15, but that only accelerates the consumption of the battery, and The fact that adjustment is not possible does not lead to communication failure, but instead the following problems occur.

For example, when making a call from a party venue, a festival site, etc., there is a case where it is desired to hear the surrounding sound to the other party in order to convey the atmosphere. However, as in the example shown in FIG. 16, if the operation threshold value of the VOX circuit 5 cannot be easily changed and the operation threshold value is set relatively high, Stops voicing, and at the same time, the VOX circuit 5 operates and the transmission is cut off. Therefore, even if it is desired to transmit the ambient sound, it cannot be transmitted.

Providing an adjustment knob of the operation threshold value adjuster 6 on the operation surface 31 of the portable telephone as a countermeasure is not a solution. This is because it is easily inferred that even if the user, who is an amateur, makes an inappropriate adjustment, even normal communication cannot be performed before the normal power saving operation.

In order to explain the third problem of the conventional radio communication device, the relationship between the loudness of the input sound to the microphone 1 and the output of the audio signal processing circuit 2 is shown in the signal characteristic diagram of FIG. In the figure, the horizontal axis represents the loudness of the input sound to the microphone 1. Here, the sound level 18 shown in FIG. 15A and the ambient sound level 1 shown in FIG.
9 and 9 are added. The vertical axis of FIG. 17 represents the output modulation degree of the audio signal processing circuit 2. Reference numeral 43 is a line showing the characteristic of the signal level. This includes both the characteristics of the microphone 1 and the characteristics of the audio signal processing circuit 2, but the sharing ratio between the two is irrelevant here and will not be described.

The characteristic line 43 is manufactured so as to show a saturation characteristic as shown in FIG. This is a necessary measure to prevent the communication quality from deteriorating due to excessive modulation of the carrier wave, resulting in overmodulation of the carrier wave, deterioration of sound quality, and spread of sidebands. It is also a treatment aimed at communicating a relatively quiet voice to the other party at a sufficiently high volume.

However, having the characteristics shown in FIG. 17 means that when the ambient sound level 19 becomes as high as the voice level 18 such as during the time t _{7 to} t _{8 in} FIG. This will cause the voice to be buried inside and difficult to hear. As a result, the clarity of communication is drastically reduced. As one example of measures against such a case, a method of canceling only the peripheral sounds by mutually canceling the peripheral sounds input from a plurality of microphones is conventionally known, but it is inconvenient in use. Yes, and not always common.

The simplest countermeasure that has been taken conventionally is
When the ambient noise becomes loud, the user who is transmitting the voice makes the voice louder. However, it is impossible for the user to know for himself how large it should be,
The conventional communication method has been to increase the voice only when requested by the communication partner. Therefore, there was a problem that communication efficiency declined, such as not being able to fully convey what was said, and having to repeat again.

In order to explain the fourth problem of the conventional radio communication apparatus, FIG. 18 is a detailed block diagram of the transceiver shown in FIG. 1-8, 14, 16, 1 in the figure
7, 32, 33, 40 and 41 are the same as those shown in FIG. 11, FIG. 12 or FIG. 37
Is a receiving circuit for processing a high frequency signal (not shown) received from the antenna 4 and outputting a sound signal, the output of which is connected to the volume adjuster 33.

Reference numeral 38 is an audio circuit that receives the output of the volume adjuster 33 and amplifies it to the electric power required to drive the speaker 32, and its output is connected to the speaker 32.
Reference numeral 39 denotes a reception power supply line that is supplied from the power supply circuit 16 to the reception circuit 37. When power is supplied to the transmission power supply line 17, power is not supplied to the reception power supply line 39, and the transmission power supply line 17 is also supplied. When the electric power is not supplied to the receiving power supply line 39, the receiving power supply line 39 is supplied with the electric power.

The reception power line 39 is used when the transmission frequency and the reception frequency of the wireless communication device are the same or close to each other, and an appropriate difference is provided between the transmission and reception frequencies as in a mobile phone. The transmitter circuit 3 and the receiver circuit 3
If 7 does not interfere even if they operate simultaneously, it is not used because it consumes little power.

Although not shown in detail in the drawing, a switching circuit, a filter circuit and the like are provided so that the output of the transmitting circuit 3 does not directly enter the receiving circuit 37. The adjustment of the output volume of the speaker 32 when the communication device configured as described above is in the receiving state is adjusted only by the manual adjustment operation so that the sound becomes louder than the noise around the vehicle according to the user's judgment.

The so-called automatic sensitivity adjustment or automatic volume adjustment circuit, which has been widely used in the past, changes the signal strength during reception, such as fading or
This is to prevent the sound volume from changing due to the sensitivity fluctuation accompanying the movement caused by the directivity of the receiving antenna, which is different from the sound volume adjustment here.

Since the volume adjusting circuit of the audio output circuit 38 of the receiving section 41 of the conventional radio communication apparatus is constructed as described above, for example, when a vehicle enters a tunnel, the surrounding sound becomes loud and the sound of the speaker 32 becomes loud. Is difficult to hear, or when the engine is stopped by stopping the running and the surrounding sound is reduced and the sound of the speaker 32 seems too loud, the volume output from the speaker does not change. Since it does not exist, the operator has to readjust the volume adjuster 33 shown in FIGS. 12 and 14 each time as necessary, which is also very troublesome when the operation is performed while driving the vehicle. There was a problem.

[0038]

Since the conventional wireless communication apparatus is constructed as described above, the first problem is that the noise level around the transmitting side changes due to changes in the running state of the vehicle. Each time it fluctuates, the operation threshold adjuster 6 has to adjust the operation threshold in accordance with this fluctuation, so that the expected operation of the VOX circuit 5 cannot be obtained.

The invention described in claim 1 is made to solve the above-mentioned problems.
A wireless communication device having a VOX circuit that does not require the user to readjust the operation of the VOX circuit without unintentional movements even if the ambient noise changes due to stoppage or other changes in circumstances. The purpose is to get.

As a second problem, when the wireless communication device is a car phone or a mobile phone, it is difficult to ask the operator for technical understanding. Therefore, the operation of the VOX circuit 5 is prevented to prevent erroneous operation. Although the threshold adjuster 6 cannot be provided on the operation panel surface, the operation threshold of the VOX circuit 5 is of course adjusted in response to changes in ambient noise, and the VOX circuit 5 operates. There is a problem that the operation of the VOX circuit 5 cannot be easily stopped when it is difficult to stop the transmission.

According to the invention described in claim 2, when the wireless communication device is an automobile telephone or a mobile telephone, the V
It is an object of the present invention to obtain a circuit in which the operation of the OX circuit can be turned on / off and there is no risk of erroneous operation.

As a third problem, when the noise around the transmitting side becomes large during the communication, the talker does not have difficulty in hearing the communication partner because his or her voice is buried in the surrounding sound. There is a problem in that it is impossible to know for yourself whether or not to make the voice louder, unless you ask the other party for communication.

According to the third aspect of the present invention, the user can always know for himself whether or not the level of the loudness of the voice when transmitting is sufficient with respect to the loudness of the ambient noise on the transmitting side. The purpose is to obtain a wireless communication device capable of

As a fourth problem, in the conventional wireless communication device, when the noise around the receiving side becomes large or small, the volume of the received sound is appropriate when necessary. In addition, there is a problem that the user has to manually adjust.

It is an object of the present invention to obtain a voice circuit in which the user does not need to adjust the reception volume each time in response to changes in ambient noise.

[0046]

According to a first aspect of the present invention, there is provided a radio communication apparatus, wherein a frequency selection circuit for detecting ambient noise on the transmitting side from a modulated input signal, and a frequency selecting circuit for detecting the ambient noise. And a threshold adjusting circuit of the VOX circuit that changes the operation threshold of the VOX circuit according to the output signal of the selection circuit.

In the vehicle-mounted wireless communication device according to the second aspect of the present invention, a threshold opening / closing switch for keeping the VOX circuit inactive is provided on the operation surface of the portable telephone.

According to a third aspect of the present invention, there is provided a vehicle-mounted wireless communication device in which a subtraction circuit for obtaining a level difference between the output signal of the frequency selection circuit and the output signal of the microphone and the level of the difference signal are It comprises a judgment circuit for comparing and judging whether or not it is a predetermined value or more, and a display circuit which is provided on the operation surface of the wireless communication device and displays the output state of the judgment circuit.

Further, in the vehicle-mounted wireless communication device according to the invention described in claim 4, a voice output adjusting circuit for adjusting the voice output level by an electric signal is provided in the receiving section, and the voice output adjusting circuit outputs the microphone. Send the ambient noise signal on the receiving side detected from the signal through the frequency selection circuit,
The audio output level is adjusted.

Further, the radio communication device according to the invention of claim 5 comprises a signal before passing through a filter circuit for extracting a frequency component contained in a human voice from a modulated input signal and a signal after passing through the filter circuit. A detection circuit for detecting the level of ambient noise from the level difference, and a voice output adjustment circuit for adjusting the received voice output level according to the detected level of ambient noise are provided.

Further, in the wireless communication apparatus according to the invention described in claim 6, the level of the modulation input signal detected by the detection circuit is
A holding circuit that captures and holds in response to the output signal of the VOX circuit, and an audio output adjusting circuit for adjusting the received audio output level according to the level of the holding signal are provided.

Further, in the wireless communication apparatus according to the invention described in claim 7, the level of the modulation input signal detected by the detection circuit is
The wireless communication device is provided with a holding circuit that captures and holds in response to an intermittent reception operation of the wireless communication device during standby, and a sound output adjusting circuit for adjusting a reception sound output level according to the level of the held signal.

Further, in the radio communication apparatus according to the invention described in claim 8, the level of the modulation input signal detected by the detection circuit is
The wireless communication device is provided with a holding circuit that is taken in and held between a call operation and the start of a call, and a voice output adjusting circuit for adjusting a received voice output level according to the level of the held signal. .

[0054]

According to the first aspect of the present invention, in the threshold value adjusting circuit, the frequency selecting circuit detects the VO in accordance with the output signal indicating the level of ambient noise detected and output from the modulation input signal.
By changing the operation threshold of the detection operation of the X circuit, when the ambient noise changes, the user can
A wireless communication device that does not require readjustment of the operation threshold of the X circuit is realized.

Further, the threshold open / close switch according to the second aspect of the present invention interrupts the input of the operation threshold to the VOX circuit at the time of operation, thereby continuously operating regardless of the presence or absence of the transmitted voice. The VOX circuit is set to have a modulation input signal.

The determination circuit according to the third aspect of the present invention determines whether the level difference between the output signal of the frequency selection circuit and the modulation input signal is a certain value or more, and the result is placed on the operation surface. By displaying on the display circuit, it is possible to confirm whether or not the loudness of the voice being transmitted is sufficient for the ambient noise.

Further, in the voice output adjusting circuit according to the invention described in claim 4, the received voice output level for receiving and outputting the signal of the communication partner is used as the output signal of the frequency selecting circuit for selecting the frequency component other than voice. By adjusting accordingly, the received voice output is automatically adjusted according to the size of the ambient noise.

Further, in the audio output adjusting circuit according to the invention described in claim 5, the received audio output level for receiving and outputting the signal of the communication partner is the level of the signal before and after passing through the filter circuit for extracting the audio frequency component. By adjusting according to the output signal of the detection circuit that detects the difference, the received voice output is automatically adjusted according to the magnitude of the ambient noise.

According to the sixth aspect of the present invention, in the voice output adjusting circuit, the holding circuit takes in and holds the received voice output level for receiving and outputting the signal of the communication partner in response to the output signal of the VOX circuit. The received voice output is automatically adjusted according to the level of ambient noise by adjusting according to the level of the modulated input signal.

According to the seventh aspect of the present invention, in the voice output control circuit, the holding circuit responds to the intermittent reception operation of the wireless communication device in the standby state of the reception voice output level for receiving and outputting the signal of the communication partner. Then, the received voice output is automatically adjusted according to the magnitude of the ambient noise by adjusting the level according to the level of the modulated input signal that is captured and held.

According to the eighth aspect of the invention, in the voice output control circuit, the holding circuit outputs the received voice output level for receiving and outputting the signal of the communication partner from the call operation of the wireless communication device to the start of the call. The received voice output is automatically adjusted according to the magnitude of the ambient noise by adjusting according to the level of the modulation input signal that is captured and held during the period.

[0062]

EXAMPLES Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a transmitting unit of a wireless communication apparatus according to an embodiment of the invention described in claim 1. In the figure, 1 to 8, 14, 16, 17, and 40 are the same as the conventional ones, and therefore their explanations are omitted. 9 is the modulation input signal 7
It is a frequency selection circuit that receives, selects a frequency component that is hardly contained in the human voice from among them, converts it into a DC signal proportional to the signal level, and outputs the DC signal. Reference numeral 10 is a DC output signal output from the frequency selecting circuit 9, and 15 is a threshold adjusting circuit of the VOX circuit 5 by adding the DC output signal 10 and the bias signal 8 from the operation threshold adjuster 6. It is an adder circuit for inputting to 14.

Here, the frequency selection circuit 9 in this embodiment, for example, is a low frequency signal which passes a low frequency signal of 200 Hz or less which is hardly contained in human voice but is often contained in vehicle noise. It is composed of a low pass filter and a detector for detecting the level of the signal passed through the low pass filter. As the filter used in the frequency selection circuit 9, a band stop filter that blocks passage of frequency components included in human voices, a high-pass filter that passes high frequency signals higher than frequency components contained in human voices. It is also possible to use.

For convenience of explaining the operation of the first embodiment, FIG. 2 is a frequency distribution explanatory diagram showing a difference in frequency components between ambient noise of a vehicle or the like and human voice. In FIG. 2, 1
Reference numeral 1 denotes a frequency component of a human voice, and 12 denotes a frequency component of a sound heard on a vehicle among noises generated by a vehicle (for example, an automobile). This figure shows a typical approximate value and is not accurate, but it shows that human voice has few components below 200 Hz, and vehicle noise contains many components below 200 Hz. Reference numeral 13 in FIG. 2 shows an example of selection characteristics of the frequency selection circuit 9 and shows that 200 Hz or less is selected.

The operation of FIG. 1 will be described. Since the frequency characteristic of the frequency selection circuit 9 is 200 Hz or less capable of detecting only the ambient noise shown in 13 of FIG. 2, the DC output signal 10 thereof is added to the bias signal 8 by the addition circuit 15 to the threshold adjustment circuit 14. When the ambient noise level 19 changes as a result of the input, the level of the DC output signal 10 also changes correspondingly, and the VOX circuit 5 operates as if the operation threshold adjuster 6 was adjusted. The threshold value changes. That is, as shown in FIG.
Changes, the operating threshold value of the VOX circuit 5 also changes in proportion to this.

On the other hand, even if a human voice is input, the output of the frequency selection circuit 9 does not change (due to the difference in frequency characteristics), so that the human voice does not change the operation threshold of the VOX circuit 5. Although the threshold value changes depending on the ambient noise, the DC output signal 10 of the frequency selection circuit 9
Since an averaging circuit, for example, a filter of about 0.5 seconds is used when converting to DC, the operation of the VOX circuit 5 does not cause so-called fluttering due to a sharp change in vehicle noise.

Since the vehicle operates as described above, the vehicle stops,
Even if the noise situation fluctuates due to running, entering a tunnel, etc., the operating threshold of the VOX circuit 5 automatically changes each time, and the transmitting circuit 3 is always in an optimum state, that is, if a person talks.
Operates and the transmission is stopped when the conversation is stopped, and the user does not need to readjust according to the situation.

Example 2. The second problem of the above-described conventional wireless communication device, that is, the operation threshold of the VOX circuit 5 is fixed and cannot be easily adjusted, may be inconvenient, which is described in the first embodiment. The use of inventions is increasingly encouraged. That is, as ambient noise increases, V
The operation threshold of the OX circuit 5 becomes high, which violates the request to transmit the ambient sound when not transmitting. A second embodiment of the present invention will be described as a means for solving the second problem including the problem promoted by the implementation of the first invention.

FIG. 3 is a block diagram showing a transmitting unit of a portable telephone set which implements the invention described in claim 2 in the case where the wireless communication device implementing the above-described first embodiment is a so-called telephone set. In the figure, reference numeral 29 is a threshold open / close switch inserted in the input of the threshold adjusting circuit 14. 1 to 1
Since 0, 14, 16 to 17 and 40 are the same as those in the first embodiment, description thereof will be omitted.

FIG. 4 is an external view showing an example of a portable telephone having the block diagram structure of FIG.
The numeral 9 is provided on the operation surface 31 that is easy to push when the telephone is held by hand. In the example of FIG. 4, the operation threshold value adjuster 6 for adjusting the VOX circuit 5 is built in and is not shown on the operation surface as in the conventional case.

In the block diagram of FIG. 3, the threshold open / close switch 29 is in the connected state when not pressed, and the DC output signal 10 of the frequency selection circuit 9 and the bias signal from the operation threshold adjuster 6 are input. The addition signal with 8 is transmitted to the threshold adjustment circuit 14. Further, when the switch is pressed, it is in a disconnection state and the operation threshold value becomes almost zero, and if there is a slight modulation input signal 7, the VOX circuit 5 operates. As a result, by pressing the threshold open / close switch 29, the user who is talking can be in a transmission state with a slight sound of the surroundings even when not speaking, and the other party can hear the surrounding noises. I can. The threshold open / close switch 29 does not set the level like the operation threshold adjuster 6, but is simply turned on / off, so that even an amateur can easily operate it.

In FIG. 3, the case where the operation threshold value of the VOX circuit 5 is automatically adjusted using the frequency selection circuit 9 and its DC output signal 10 shown in FIG. 1 has been described. This is shown as an example in which the first invention promotes the second problem as described above. To achieve the object of the invention described in claim 2, the frequency selection circuit 9 and the DC output signal 10 are , The same effect can be obtained without using it.

Example 3. Next, FIG. 5 is a block diagram showing an embodiment in which the invention described in claim 3 is applied to a wireless communication device, and FIG. 5 shows only a transmitting part in a transmitting / receiving circuit. In the figure, 25 is an averaging circuit for averaging the modulated input signal 7. 26 is a subtraction circuit, which obtains the difference between the DC output signal 10 of the frequency selection circuit 9 and the output of the averaging circuit 25.

Reference numeral 27 denotes a judgment circuit, which compares and judges the output of the subtraction circuit 26 with a constant value (not shown) inside the judgment circuit 27, and if the output of the subtraction circuit 26 is higher, for example. , Outputs a signal. Reference numeral 28 denotes a display circuit, which uses, for example, a display lamp or a character display device to display while the determination circuit 27 outputs a signal.

FIG. 6 shows an example of the external appearance of a wireless communication device using the block diagram of FIG. As shown, the display circuit 28
Is provided at a position on the operation surface 31 that is easy to see. Note that the other parts are the same as the corresponding parts in FIG.

The operation of the third embodiment will be described with reference to FIGS. Now, it is assumed that the transmission is performed from a place where the ambient noise is large. At this time, the modulated input signal 7 includes ambient noise as well as human voice. The averaging circuit 25 averages components of 200 Hz or higher corresponding to frequency components of human voice. That is, it can be said that the output of the averaging circuit 25 roughly represents the sound level, and the DC output signal 10 of the frequency selection circuit 9 roughly represents the noise level.

Therefore, the difference signal obtained by the subtraction circuit 26 roughly represents the size of the portion of the voice signal that is larger than the inner ambient noise. The comparison circuit 27 determines whether or not the size of the portion of the audio signal larger than the ambient noise is equal to or larger than a certain value. If the signal is sufficiently large, the display circuit 28 is turned on to notify that the voice is sufficiently loud. If the noise is low, the display circuit 2
8 lights up, but if there is noise, the display circuit 28 does not light up unless the loudness of the voice is increased according to the loudness of the noise.

In the third embodiment shown in FIG. 5, the output of the frequency selection circuit 9 is the same as in the first embodiment shown in FIG.
In order to show that the performance of the frequency selection circuit 9 in the third embodiment is exactly the same as that in FIG. 1 of the first embodiment, the invention described in claim 3 is connected. 1 shows a case where the apparatus is used in Example 1. That is, according to the third aspect of the invention, the same effect can be obtained even if the output of the frequency selection circuit 9 is not connected to the threshold adjustment circuit 14. Also, without the VOX circuit 5,
It can also be used in a so-called PTT switch type wireless communication device.

Further, the averaging circuit 25 shown in FIG. 5 may use the circuit included in the VOX circuit 5 without providing it independently. Further, the frequency characteristic of the averaging circuit 25 may be extracted by limiting an extremely narrow frequency of voice, for example, a range of 500 to 2000 Hz. By talking while seeing the lighting state of the display circuit 28, the talker can communicate while confirming that his or her voice is not buried in the ambient noise.

Example 4. Next, FIG. 7 shows a block diagram of a wireless communication apparatus according to an embodiment of the invention described in claim 4. In the figure, reference numeral 42 is a voice output adjusting circuit capable of changing the amplification factor by an electric signal, and amplifies or reduces the received voice signal which is the output of the receiving circuit 37. The DC output signal 10 of the frequency selection circuit 9 is input as an amplification factor control input of the audio output adjustment circuit 42.

To explain the operation of the audio output adjusting circuit 42, FIG. 8 shows an example of the characteristics of the audio output adjusting circuit. The horizontal axis of the figure shows the magnitude of the DC output signal 10 of the frequency selecting circuit 9, that is, the magnitude of ambient noise, and the vertical axis of the figure shows the amplification factor of the audio output adjusting circuit 42. When the DC output signal 10 of the frequency selection circuit 9 is zero, that is, when the ambient noise is zero, the amplification factor is 1, for example, and as the DC output signal 10 of the frequency selection circuit 9 increases, the amplification factor increases, for example, up to 5 It is set to about double. That is, the amplification factor increases as the ambient noise increases, and as a result, the received voice output from the speaker 32 becomes louder.

Since the microphone 1 and the frequency selection circuit 9 are always in operation regardless of whether the wireless device is transmitting or receiving, noise around the transmitter can be detected during transmission. It means that the noise around the receiver can be detected during reception.

As a result, when the ambient noise changes momentarily as the vehicle travels, the received sound volume emitted from the speaker 32 automatically changes in accordance with the ambient noise input from the microphone 1 that should originally be used for transmission. The operator does not need to make adjustments one by one and can always obtain a sufficient volume of audio output that is easy to hear.

In the block diagram of FIG. 7, the DC output signal 10 of the frequency selection circuit 9 is directly fed to the audio output control circuit 42.
However, it is also possible to insert a variable resistor in the middle so as to adjust the degree of change of the amplification factor appropriately. The change width of the amplification factor of the audio output adjusting circuit 42 shown in FIG. 8 may be changed from 1 or less, and the maximum value does not need to be 5 times.

In FIG. 7 of the fourth embodiment, the frequency selection circuit 9
The DC output signal 10 is connected to the threshold adjusting circuit 14 as in the case of the first embodiment. This is because the performance of the frequency selecting circuit 9 in the fourth embodiment is the same as that of the first embodiment. In order to show that it is exactly the same as that of No. 1, the case of using the invention described in claim 4 in the device of the first embodiment is shown. That is, in the invention described in claim 4, the same effect can be obtained even if the DC output signal 10 of the frequency selection circuit 9 is not connected to the threshold value adjustment circuit 14.
It can also be used in a so-called PTT switch type wireless communication device that does not have the VOX circuit 5.

Example 5. Next, FIG. 9 shows a block diagram of a wireless communication device according to an embodiment of the invention described in claim 5. In the figure, reference numeral 44 is a filter circuit for extracting the frequency component contained in the human voice from the modulated input signal 7, which is realized by a voice bandpass filter normally provided in the first stage of the wireless communication device. be able to. Reference numeral 45 is a subtraction circuit for obtaining the difference between the level of the modulated input signal 7 before passing through the filter circuit 44 and the level of the signal after passing through the filter circuit 44. 46 detects the ambient noise level from the signal output from the subtraction circuit 45, inputs it to the voice output control circuit 42, and receives the output signal level of the communication partner to output the received voice output level of the ambient noise. It is a detection circuit that is adjusted according to the level.

The modulated input signal 7 input from the microphone 1 is input to the filter circuit 44 to extract the frequency component contained in the human voice, which is input to the voice signal processing circuit 2 and the subtraction circuit 45. The modulation input signal 7 from the microphone 1 is also input to the subtraction circuit 45 as it is. Therefore, from the subtraction circuit 45, the modulated input signal 7 including the transmission voice before passing through the filter circuit 44 and the ambient noise, and the transmission voice signal from which the ambient noise component is removed by the filter circuit 44 are output. Only the ambient noise component, which is the difference between the two, is output. The detection circuit 46 detects the level of this ambient noise and inputs it to the audio output adjustment circuit 42. According to the output signal of the detection circuit 46, the voice output adjusting circuit 42 automatically adjusts the received voice output by changing its amplification factor to be small if the ambient noise level is low and to be large if it is high.

In the fifth embodiment as well, the VOX circuit 5 controls the power supply circuit 16.
It can also be used in a PTT switch type wireless communication device that does not have the circuit 5.

Example 6. Next, FIG. 10 shows a block diagram of a wireless communication device according to an embodiment of the invention described in claim 6.
In the figure, 47 is a detection circuit for detecting the level of the modulation input signal 7, and 48 is the VOX circuit 5 which supplies the level of the modulation input signal 7 detected by the detection circuit 47 for power saving. It is a holding circuit that responds to the signal output to the circuit 16 and captures and holds the signal, and inputs the level signal of the held modulation input signal 7 to the audio output adjusting circuit 42.

The modulated input signal 7 input from the microphone 1 is input to the audio signal processing circuit 2 and the detection circuit 47. The detection circuit 47 detects the level of the input modulation input signal 7, generates a DC signal corresponding to the level, and inputs the DC signal to the holding circuit 48. This holding circuit 48 is a VOX
The circuit 5 detects the presence or absence of the modulation input signal 7 and outputs a signal to control the power supply circuit 16, which switches between capturing and holding the DC signal output from the detection circuit 47. That is, when the transmission is off, the DC signal is taken in, and when the transmission is on, it is held. This makes it possible to capture the ambient noise level when there is no transmitted voice and to keep that value when there is transmitted voice. By inputting the signal held by the holding circuit 48 to the audio output adjusting circuit 42, the audio output adjusting circuit 42 changes the amplification factor of itself when the ambient noise level is low, and changes it greatly when the ambient noise level is high, Adjust the received audio output automatically.

Example 7. In the above-described sixth embodiment, the case where the holding circuit 48 is switched between loading and holding in accordance with the output signal of the VOX circuit 5 has been described. However, switching is performed in response to the intermittent reception operation in the standby state of the wireless communication device. Of course, the same effect as that of the sixth embodiment can be obtained. That is, when the wireless communication device is in the standby state,
Although the intermittent reception operation is performed, the DC signal output from the detection circuit 47 is switched between capturing and holding at that timing. Therefore, at the time of an incoming call, the level of ambient noise immediately before the start of the call can be held in the holding circuit 48, and if the holding signal controls the amplification factor of the audio signal adjusting circuit 42,
The received voice output can be adjusted automatically.

The seventh embodiment cannot cope with the temporal change of the ambient noise during a call, and is effective when used in the case where the ambient noise does not change much after the incoming call.

Example 8. In the sixth and seventh embodiments, the case where the DC signal is taken in and held in the holding circuit 48 according to the output signal of the VOX circuit 5 or the intermittent reception operation during standby has been described. The DC signal from the detection circuit 47 may be fetched and held during the time from the calling operation to the start of the call at any time, and the same effect as that of the sixth or seventh embodiment is obtained. That is, when a call is made from the wireless communication device, it takes several seconds from the time when the user performs a call operation until the time when the call is actually started due to the sequence relationship with the base station. Here, by capturing the DC signal output from the detection circuit 47 and holding it in the holding circuit 48 during that time, the level of ambient noise immediately before the start of the call can be held. By controlling the amplification factor of the audio signal adjusting circuit 42 by the holding signal of the holding circuit 48, the received audio output can be automatically adjusted.

The eighth embodiment cannot cope with the temporal change in the ambient noise during a call, and is effective when used in the case where the ambient noise does not change much after the call is made.

In the above description, an example in which the wireless communication device is loaded in a vehicle has been described, but communication used in a place where the noise level in the surroundings fluctuates, for example, in a noise area in a ship, an airplane, a train, or a factory. It is also applicable to all devices.

[0096]

As described above, according to the invention described in claim 1, since the operation threshold value of the VOX circuit is changed according to the level of the ambient noise detected by the frequency selection circuit, for example, the vehicle. Depending on the running condition and surrounding changes,
Even if the amount of noise around the transmitting side changes, the operation threshold of the VOX circuit is automatically adjusted according to the noise, and a wireless communication device that does not require the user to readjust is obtained. There is.

Further, according to the invention described in claim 2, in the telephone, the push-button switch, which is continuously in the transmission state by pressing it during a call, is arranged on the operation surface. , Regardless of whether the VOX circuit is operating or not
The effect is that a call including ambient noise can be easily made.

According to the third aspect of the present invention, the display circuit indicates that the level difference between the output signal of the frequency selection circuit and the modulation input signal exceeds a certain value. When the noise in the room becomes louder, the user can recognize whether or not the loudness of his / her own voice speaking into the microphone is sufficiently higher than the ambient noise, and communication can be performed efficiently. Is effective.

Further, according to the invention described in claim 4, since the audio output adjusting circuit is controlled by the output signal of the frequency selecting circuit, the speaker is influenced by the noise around the receiving side during reception. This has the effect of eliminating the need for the user to readjust the volume of the received voice output from the user.

According to the invention described in claim 5, the received voice output level is adjusted according to the output signal of the detection circuit for detecting the level difference between the signal before and after passing through the filter circuit for extracting the voice frequency component. With this configuration, there is an effect that the user does not need to readjust the volume of the received voice according to the magnitude of the ambient noise.

According to the invention described in claim 6, VO
Since the received signal output level is adjusted by the holding signal of the holding circuit that is taken in and held in response to the output signal of the X circuit, the user can adjust the received sound level according to the magnitude of the ambient noise. The effect is that there is no need to readjust.

Further, according to the invention described in claim 7, the reception voice output level is adjusted by the holding signal of the holding circuit fetched and held in accordance with the intermittent receiving operation of the wireless communication device during standby. Therefore, there is an effect that the user does not need to readjust the loudness of the received voice according to the magnitude of the ambient noise.

According to the invention described in claim 8, the reception voice output level is adjusted by the holding signal of the holding circuit which is taken in and held between the call operation of the wireless communication device and the start of the call. With this configuration, there is an effect that the user does not need to readjust the volume of the received voice according to the magnitude of the ambient noise.

[Brief description of drawings]

FIG. 1 is a block diagram showing a transmitting unit of a wireless communication device according to a first embodiment of the present invention.

FIG. 2 is a frequency distribution explanatory diagram for explaining the operation of the above embodiment.

FIG. 3 is a block diagram showing a transmitter of a wireless communication device according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing an external appearance of the mobile phone according to the embodiment.

FIG. 5 is a block diagram showing a transmitter of a wireless communication device according to a third embodiment of the present invention.

FIG. 6 is a perspective view showing the outer appearance of the wireless communication device according to the embodiment.

FIG. 7 is a block diagram showing a wireless communication device according to Embodiment 4 of the present invention.

FIG. 8 is an explanatory diagram showing characteristics of the audio output adjusting circuit in the above embodiment.

FIG. 9 is a block diagram showing a wireless communication device according to a fifth embodiment of the present invention.

FIG. 10 is a block diagram showing a wireless communication device according to a sixth embodiment of the present invention.

FIG. 11 is a block diagram showing an overall configuration of a conventional wireless communication device.

FIG. 12 is a block diagram showing a transmitter of a conventional wireless communication device.

FIG. 13 is an explanatory diagram showing input / output characteristics of a conventional VOX circuit.

FIG. 14 is a perspective view showing an appearance of a conventional wireless communication device.

FIG. 15 is an explanatory diagram showing an operating condition of a VOX circuit.

FIG. 16 is a perspective view showing an appearance of a conventional mobile phone.

FIG. 17 is a signal characteristic diagram showing the relationship between the volume of the sound input to the microphone and the output of the audio signal processing circuit.

FIG. 18 is a block diagram showing details of an entire conventional wireless communication device.

[Explanation of symbols]

 3 Transmitter Circuit 5 Input Signal Detection Circuit (VOX Circuit) 9 Frequency Selection Circuit 14 Threshold Adjustment Circuit 16 Power Supply Circuit 26 Subtraction Circuit 27 Judgment Circuit 28 Display Circuit 29 Threshold Open / Close Switch 31 Operation Surface 42 Voice Output Control Circuit 44 Filter circuit 45 Subtraction circuit 46 Detection circuit 47 Detection circuit 48 Holding circuit

Claims (8)

[Claims] 1. An input signal detection circuit for detecting the presence or absence of a modulation input signal given as a modulation input to a transmission circuit for transmitting a communication radio wave, and when the modulation input signal is not detected by the input signal detection circuit, In a wireless communication device equipped with a power supply circuit that cuts off or reduces the power supplied to the transmission circuit, a frequency selection circuit that selects a frequency of a component that is hardly contained in human voice from the modulation input signal, A wireless communication device comprising a threshold value adjusting circuit for changing an operation threshold value of a detection operation of the input signal detecting circuit according to an output signal of the frequency selecting circuit. 2. A threshold opening / closing switch for opening / closing an input of the threshold adjusting circuit is arranged on an operation surface for performing a wireless communication operation of the wireless communication apparatus.
The wireless communication device according to. 3. A frequency selection circuit for selecting a frequency of a component which is hardly contained in human voice from a modulation input signal given as a modulation input to a transmission circuit for transmitting communication radio waves, and an output of this frequency selection circuit. A subtraction circuit for obtaining the difference between the level of the signal and the level of the modulated input signal, a determination circuit for determining whether the level of the signal output from the subtraction circuit is a certain value or more, and the radio circuit A wireless communication device, comprising: a display circuit arranged on an operation surface for performing wireless communication operation of the communication device, the display circuit being operated by an output signal of the determination circuit. 4. A frequency selection circuit for selecting a frequency of a component which is hardly contained in human voice from a modulation input signal given as a modulation input to a transmission circuit for transmitting communication radio waves, and a signal of a communication partner is received. And a voice output adjusting circuit for adjusting the received voice output level to be output according to the level of the output signal of the frequency selection circuit. 5. A filter circuit for extracting a frequency component contained in a human voice from a modulation input signal given as a modulation input to a transmission circuit for transmitting communication radio waves, and a signal level before passing through the filter circuit. A subtraction circuit that finds the difference between the signal level after passing through, a detection circuit that detects the ambient noise level from the output signal of this subtraction circuit, and a received voice output level that receives and outputs the signal of the communication partner. To
A wireless communication device comprising: a voice output adjusting circuit for adjusting according to a level of ambient noise detected by the detecting circuit. 6. A detection circuit for detecting the level of a modulation input signal given as a modulation input to a transmission circuit for transmitting a communication radio wave, and a level of the modulation input signal detected by the detection circuit, the presence or absence of the modulation input signal. In response to the output signal of the input signal detection circuit that detects the signal, a holding circuit that captures and holds the signal, and a received voice output level that receives and outputs the signal of the communication partner, according to the signal level held in the holding circuit. A wireless communication device having a voice output adjusting circuit for adjusting. 7. A detection circuit for detecting the level of a modulation input signal given as a modulation input to a transmission circuit for transmitting a communication radio wave, and the wireless communication device waiting for the level of the modulation input signal detected by the detection circuit. The holding circuit that captures and holds in response to the intermittent reception operation when in the state and the reception voice output level that receives and outputs the signal of the communication partner are adjusted according to the signal level held in the holding circuit. A wireless communication device including a voice output adjustment circuit for performing the operation. 8. A detection circuit for detecting the level of a modulation input signal applied as a modulation input to a transmission circuit for transmitting a communication radio wave, and a detection circuit for making a call between the wireless communication device and the start of a call. A holding circuit that captures and holds the level of the modulated input signal detected by the detection circuit, and a received voice output level that receives and outputs the signal of the communication partner, according to the signal level held in the holding circuit. A wireless communication device having an audio output adjusting circuit for adjusting.