JP2002076961A - Portable communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable communication device capable of eliminating noise components caused by timing control from speech signals without increasing the size of the device and costs. SOLUTION: A timing control unit 13 supplies a control signal required for an intermittent operation to a transmitter/receiver 12, and further also supplies to a dummy noise generation part 24. The dummy noise generation part 24 synchronizes with the control signal, while generating a dummy noise signal having a waveform pattern of a reverse phase. The dummy noise signal adjusted in a level by a reception side level adjustment part 25 and a reception speech signal output from a DA converter 15 are supplied to a reception noise elimination part 16, and the dummy noise signal is subtracted from the speech signal, thereby eliminating noise components. Further, the noise components are eliminated from a transmission speech signal with the same structure on a transmission side. Thus, the speech signal in which the noise caused by the intermittent operation is eliminated is transmitted and received, thereby realizing a comfortable communication in a mobile telephone system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable communication device such as a portable telephone device provided with wireless communication means, and more particularly to a portable communication device configured to intermittently control a wireless communication operation at a predetermined control timing. It belongs to the technical field.

[0002]

2. Description of the Related Art In recent years, in portable telephone devices which have been rapidly spreading, reduction in power consumption of products has conventionally been an issue. Further, in order to enable a large number of mobile telephone devices to be used in a certain area, it is necessary to secure a large number of communication channels. In order to realize such low power consumption and multi-channel, intermittent control of a transmission operation and a reception operation of a mobile phone device is adopted. That is, wireless communication is performed by allocating a transmission slot and a reception slot according to a preset control timing and periodically repeating the transmission operation and the reception operation of the audio data.

[0003]

When the intermittent control of the portable telephone device as described above is performed, a radio circuit such as a power amplifier alternately turns on and off in accordance with a control signal defining a control timing, and interlocks with the cycle. As a result, the operating current changes in a burst manner. Therefore, the power supply voltage may fluctuate in each part of the mobile phone device driven by the battery, and a noise component may be generated in synchronization with the control timing. As a result, even in the audio circuit, a noise component having the same cycle as the control timing is superimposed on the audio signal, and there is a possibility that the sound quality of the mobile phone device is degraded.

On the other hand, as a countermeasure against noise of the above-mentioned voice signal,
It is also conceivable to provide a power supply ripple elimination circuit or to surround the substrate with a large-scale shield case. However, these measures hindered the miniaturization of mobile phone devices,
The problem is to increase costs.

Accordingly, the present invention has been made in view of such a problem, and does not increase the size and cost of the apparatus, and eliminates noise components due to power supply fluctuations caused by timing control of intermittent operation. It is an object of the present invention to provide a mobile communication device that can be removed from a mobile communication device.

[0006]

According to a first aspect of the present invention, there is provided a portable communication device for transmitting and receiving a voice signal by wireless communication, wherein the portable communication device performs an intermittent operation of the wireless communication. Timing control means for generating a timing control signal to be controlled; and a pseudo-signal for generating a pseudo-noise signal by setting a waveform pattern of a noise component superimposed on the audio signal due to the intermittent operation based on the timing control signal. A noise generating unit; and a noise removing unit that removes the noise component by subtracting the pseudo noise signal from the audio signal.

According to the present invention, when the wireless communication of the portable communication device is started, an intermittent operation is performed based on the timing control signal, and a process for removing a noise component caused by the intermittent operation is performed. Then, a pseudo noise signal having a waveform pattern set based on the timing control signal is generated, and the noise is removed by subtracting the pseudo noise signal from the audio signal. Therefore, an unpleasant noise component included in the audio signal can be canceled by the pseudo noise signal in conjunction with the power control or the like accompanying the intermittent operation, and a portable communication device that allows a user to make a comfortable call can be realized. .

According to a second aspect of the present invention, in the portable communication apparatus according to the first aspect, the timing control signal is a rectangle which periodically repeats a high level and a low level in accordance with the state of the intermittent operation. And wherein the pseudo-noise generation means sets a rectangular wave having a phase opposite to that of the control signal as a waveform pattern.

According to the present invention, it is possible to use a timing control signal which is a rectangular wave having a constant period, and to easily generate a pseudo-noise signal synchronously with the timing control signal and having a waveform of an opposite phase. Therefore, it is possible to effectively remove the noise component from the audio signal without complicating the circuit configuration.

According to a third aspect of the present invention, in the portable communication apparatus according to the first aspect, the level of the pseudo noise signal is adjusted in accordance with a state of wireless communication and supplied to the noise removing unit. And adjusting means.

According to the present invention, after the pseudo noise signal is generated, the level of the pseudo noise signal is appropriately adjusted according to the state of wireless communication, and then used for the above-described noise removal. Therefore, for example, even when the level is switched in multiple stages according to the electric field strength or the like, the adjustment can be performed so that an appropriate pseudo noise level can be obtained.

According to a fourth aspect of the present invention, in the portable communication apparatus according to the first aspect, the noise removing unit subtracts the pseudo noise signal from a received voice signal to reduce a noise component on the receiving side. It is characterized by including reception noise removal means for removing, and transmission noise removal means for removing the noise component on the transmission side by subtracting the pseudo noise signal from the transmission voice signal.

According to the present invention, the process of removing the noise component on the receiving side and the process of removing the noise component on the transmitting side are separately performed based on the pseudo noise signal. Therefore, it is possible to easily cope with the case where the operation conditions and the configuration of the transmission and the reception are different, and it is possible to make a comfortable call for both the user of the portable communication device and the other party of the call.

According to a fifth aspect of the present invention, in the portable communication device according to the fourth aspect, the level of the pseudo noise signal is adjusted in accordance with the state of wireless communication and supplied to the reception noise removing unit. It is characterized by further comprising a receiving-side level adjusting means, and a transmitting-side level adjusting means for performing level adjustment of the pseudo noise signal in accordance with a state of wireless communication and supplying the adjusted level to the transmission noise removing means.

According to the present invention, for a pseudo noise signal,
After separately performing level adjustment on the receiving side and the transmitting side, processing for removing noise components is performed. Therefore, it is possible to easily cope with the case where the level setting of transmission and reception and the degree of influence of noise are different, and it is possible to make a comfortable call for both the user of the portable communication device and the other party of the call.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, an example will be described in which the mobile communication device of the present invention is applied to a mobile phone device that wirelessly transmits and receives audio signals as digital data.

FIG. 1 is a block diagram showing a schematic configuration of the portable telephone device according to the present embodiment. The mobile phone device shown in FIG. 1 includes an antenna 11, a radio unit 12, a timing control unit 13, a reception data processing unit 14, a DA converter 15, a reception noise removal unit 16, and a reception audio amplifier 17.
, Receiver 18, microphone 19, transmission audio amplifier 20, transmission noise removing unit 21, AD converter 22
A transmission data processing unit 23, a pseudo noise generation unit 24,
It comprises a reception-side level adjustment unit 25 and a transmission-side level adjustment unit 26.

In the above configuration, the antenna 11 transmits and receives radio waves to and from the base station installed in the area where the portable telephone device is located, supplies a received signal to the radio unit 12 and outputs the received signal from the radio unit 12. The transmitted signal is radiated as a radio wave.

The radio section 12 includes an antenna switch 12a, a receiving circuit 12b, and a transmitting circuit 12c. The antenna changeover switch 12a connects the antenna 11 to the reception circuit 12b or the transmission circuit 12c.
Means for switching to one of the above. Further, when diversity reception is performed in the mobile phone device, a configuration in which the antenna switch 12a is controlled to switch the connection with the antenna 11 can be adopted. The switching timing of the antenna switch 12a is defined by a control signal supplied from the timing control unit 13. The switching timing of the antenna switch 12a will be described later.

The receiving circuit 12b included in the radio unit 12 includes:
After performing a reception operation on a reception signal input from the antenna 11 via the antenna changeover switch 12a and passing through a high-frequency circuit including a reception amplifier and a filter,
The extracted reception data is output to the reception data processing unit 14. In the receiving circuit 12b, the above-described receiving operation is intermittently performed during the period of the receiving slot determined by the control signal from the timing control unit 13.

The transmission circuit 12 included in the radio section 12
c performs a transmission operation on the transmission data output from the transmission data processing unit 23, amplifies the transmission signal modulated based on the transmission data by the transmission power amplifier, and transmits the amplified signal to the antenna 11 via the antenna switch 12a. Output. In the transmission circuit 12c, the above transmission operation is executed intermittently during the period of the transmission slot determined by the control signal from the timing control unit 13.

Next, the timing control section 13 generates a control signal for performing timing control corresponding to the communication protocol of the portable telephone device. Specifically, the timing control unit 13 supplies a reception timing control signal defining the reception slot to the reception circuit 12b and defines the transmission slot in order to allocate the reception slot and the transmission slot at regular intervals during a call. The transmission timing control signal is supplied to the transmission circuit 12b. In the radio unit 12, on / off control of the power supply in the receiving system and the transmitting system and switching control of the antenna switch 12a are performed.
It is executed based on a control signal supplied from the timing control unit 13. The transmission timing control signal from the timing control unit 13 is transmitted to the pseudo noise generation unit 24 as described later.
And is used as a timing reference for the waveform pattern of the pseudo noise.

Next, the reception data processing section 14 performs various signal processing on the reception data extracted by the reception circuit 12b and outputs a digital audio signal. Then, the DA converter 15 converts the digital audio signal output from the reception data processing unit 14 into an analog audio signal and outputs the analog audio signal.

Next, the reception noise removing section 16 removes the noise component caused by the intermittent operation contained in the analog audio signal output from the DA converter 15 by the pseudo noise generating section 24 and the receiving side level adjusting section 25. And outputs a received audio signal obtained by subtracting the received pseudo noise signal supplied via the analog audio signal from the analog audio signal. The operation of the noise removal in the reception noise removal unit 16 will be described later.

The received voice signal from which the noise component has been removed by the received noise removing unit 16 is supplied to the received voice amplifier 1.
After being amplified to a predetermined level by the receiver 7, the receiver 18
Is externally output as a received voice.

On the other hand, the microphone 19 generates a transmission voice signal based on the transmission voice input externally. Then, the transmission audio signal amplified to a predetermined level by the transmission audio amplifier 20 is input to the transmission noise removing unit 21.

The transmission noise removing section 21 removes the transmission pseudo-noise signal supplied from the transmission noise generating section 24 via the transmission-side level adjusting section 26 in order to remove the noise component caused by the intermittent operation included in the transmission voice signal. Is subtracted from the transmission audio signal to output an analog audio signal. The operation of the transmission noise removing unit 21 for removing noise will be described later.

Next, the AD converter 15 converts the analog voice signal from which the noise component has been removed by the transmission noise removing unit 21 into a digital voice signal and outputs the digital voice signal. And
After performing various signal processing on the digital audio signal output from the AD converter 22, the transmission data processing unit 23 generates and outputs transmission data to be wirelessly transmitted. As described above, the transmission data output from the transmission data processing unit 23 is transmitted as a radio wave from the antenna 11 via the transmission circuit 12c of the radio unit 12 and the antenna switch 12a.

In the configuration shown in FIG. 1, the positional relationship between the reception noise elimination unit 16 and the reception voice amplifier 17 is reversed.
The same effect can be obtained by arranging the reception noise removal unit 16 after the reception audio amplifier 17. In this case,
It is necessary to appropriately change the level of the reception pseudo noise signal supplied to the reception noise removal unit 16.

Next, with reference to FIG. 2, a process of generating a pseudo-noise signal and a process of removing noise from a received voice in this embodiment will be specifically described. FIG. 2 is a diagram showing a waveform pattern of each section of the mobile phone device of FIG.

In FIG. 2, the reception timing control signal (a), the transmission timing control signal (a), the analog audio signal (c) output from the DA converter 15, The reception pseudo noise signal (d) output from the reception-side level adjustment unit 25 and the reception audio signal (e) output from the reception audio amplifier 17 are shown in order in comparison with each other.

First, in the reception timing control signal of the waveform pattern a, a high level period corresponds to a reception slot, and a reception slot is repeatedly assigned at a constant period T. During this period, the intermittent operation in the reception circuit 12b is performed. A simple receiving operation is performed. Further, in the transmission timing control signal of the waveform b, a period in which the reception slot is at a high level prior to the reception slot corresponds to the transmission slot, and the transmission slot is repeatedly assigned with a period T like the reception slot,
During this period, the intermittent transmission operation in the transmission circuit 12c is performed. Note that the cycle T is set to, for example, about 50 ms.

Next, it can be seen that the analog audio signal of the waveform pattern c has a waveform pattern in which a noise component is superimposed at a constant period on a sinusoidal signal component. That is, the original received voice signal component is represented in a sine wave shape, and the noise signal component superimposed thereon has a proportional relationship with the transmission timing control signal of the waveform pattern b. As shown by the dotted line in the figure, discontinuous ripple occurs in the analog audio signal at the timing when the level of the transmission timing control signal switches, and the level of the analog audio signal is increased when the transmission timing control signal is at a low level. , When the transmission timing control signal is at a high level, the level of the analog audio signal is reduced.

Such a noise signal component proportional to the transmission timing control signal is caused by power supply control in the transmission circuit 12c. That is, during the transmission slot, the transmission power is turned on, and the current consumed in the transmission system increases. As a result, the power supply voltage of the battery-driven mobile phone device fluctuates, affecting the signal level on the receiving side. It is. In particular, it is greatly affected by the on / off control of the transmission power amplifier that consumes a large amount of power. The effect of power control by the reception timing control signal is negligible because the current consumed in the reception system is relatively small.

When sound is output in the state of the waveform pattern c, unpleasant noise is generated for the user. Therefore, in this embodiment, the following noise countermeasures are taken. First, the pseudo noise generation unit 24 generates a reception pseudo noise signal. As shown in FIG. 2, the reception pseudo-noise signal has a waveform pattern of a predetermined level in which the polarity is reversed while being synchronized with the timing control signal defining the transmission slot as described above.

In the pseudo noise generator 24, the transmission timing control signal is supplied from the timing controller 13, so that
As shown by the waveform pattern d in the figure, the level change point can be accurately synchronized with the transmission timing control signal. The level of the reception pseudo noise signal is set to a predetermined level in consideration of noise received by the reception system.
Here, it is generally assumed that, under the same design conditions, the effect of noise is also substantially the same.

The reception pseudo-noise signal generated in this way is subjected to level adjustment by the reception-side level adjustment section 25. When using a mobile phone device, the transmission power can be switched and set in multiple stages according to the state of wireless communication,
As a result, the level of the pseudo-noise reception signal is appropriately adjusted by the reception-side level adjustment unit 25 in order to compensate for the fluctuation of the influence of noise. For example, the radio unit 12 is controlled to increase the transmission power under a weak electric field and decrease the transmission power under a strong electric field. For this reason, the current consumption fluctuates every moment depending on the wireless situation, and it is necessary to control the level of the received pseudo noise signal so as to follow this.

When the received pseudo-noise signal whose level has been adjusted as described above is supplied to the reception noise removal section 16, the reception voice signal from which the noise component has been removed is obtained as shown by the waveform pattern e in FIG. can get. When the waveform pattern e is compared with the waveform pattern c, since noise due to transmission timing control has been removed, no unpleasant noise is generated for the user.

In FIG. 2, the pseudo noise signal generation processing and the noise removal processing have been described by taking the receiving system as an example. However, the case of the transmitting system can be similarly considered. However, since the influence of noise differs between the transmission system and the reception system, the level adjustment in the transmission-side level adjustment unit 26 needs to be changed from the setting in the reception-side level adjustment unit 25.

As described above, according to the present embodiment, the noise component superimposed on the audio signal due to the timing control for the radio unit 12 can be effectively removed. At this time, since the pseudo noise signal is generated by the pseudo noise generator 24 based on the control signal supplied from the timing controller 13, a waveform pattern accurately synchronized with the noise can be obtained. Also, the receiving-side level adjusting unit 25
Since the level adjustment is performed on the pseudo-noise signal in the transmission-side level adjustment section 26 and the transmission-side level adjustment section 26, it is possible to easily cope with the case where the influences of the noises on the reception side and the transmission side are different.

Next, a modified example of this embodiment will be described with reference to FIG. FIG. 3 is a block diagram illustrating a schematic configuration corresponding to FIG. 1 in a case where noise removal processing using a pseudo noise signal is performed by digital operation.

In FIG. 3, the antenna 11 and the radio unit 1
2, a timing control unit 13, and a reception data processing unit 14
, A DA converter 15, a receiving voice amplifier 17,
Receiver 18, microphone 19, and transmission audio amplifier 20
, The AD converter 22, and the transmission data processing unit 23 have the same configuration as that in FIG. On the other hand, in FIG.
, The reception-side level adjustment unit 32, and the transmission-side level adjustment unit 3
3, the reception noise removal unit 34, and the transmission noise removal unit 35
FIG. 1 shows that each of them is configured corresponding to a digital operation.
Is different from

The pseudo-noise generator 31 sets a waveform pattern similar to that shown in FIG. 2 as digital data, and outputs a pseudo-noise signal by reading out the digital data at a predetermined timing, for example, by holding it in storage means.

The digital data output from the pseudo noise generator 31 is adjusted by the receiver-side level adjuster 32 by digital operation to adjust the level of the digital signal to the receiver. The transmission-side level adjustment unit 33 performs appropriate level adjustment on the transmission side by digital operation. The receiving-side level adjusting unit 32 and the transmitting-side level adjusting unit 33 include a receiving-side level adjusting unit 25 and a transmitting-side level adjusting unit 26 shown in FIG.
What is necessary is just to set the same level adjustment amount as.

The reception noise removal unit 34 performs the above-described subtraction processing by digital operation using the digital data output from the reception data processing unit 14 and the digital data output from the reception-side level adjustment unit 32.
Similarly, the transmission noise elimination unit 35 performs the above-described subtraction processing by digital operation using the digital data output from the AD converter 22 and the digital data output from the transmission-side level adjustment unit 33.

As described above, in the modified example shown in FIG. 3, since the noise removal processing is performed by the digital operation using the digital data, the circuit configuration can be simplified.
In particular, all of the digital arithmetic processing can be integrated in a specific IC, which is advantageous for miniaturization of products.

[0047]

As described above, according to the present invention,
Since a noise component caused by intermittent operation of wireless communication is effectively removed, a portable communication device capable of realizing comfortable wireless communication can be provided without increasing the size and cost of the device.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a mobile phone device according to an embodiment.

FIG. 2 is an explanatory diagram of a process of generating a pseudo noise signal and a process of removing noise from a received voice in the embodiment.

FIG. 3 is a block diagram illustrating a schematic configuration of a mobile phone device according to a modified example of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Antenna 12 ... Radio | wireless part 12a ... Antenna changeover switch 12b ... Reception circuit 12c ... Transmission circuit 13 ... Timing control part 14 ... Reception data processing part 15 ... DA converter 16, 34 ... Reception noise removal part 17 ... Reception audio amplifier 18 ... Receiver 19 ... Microphone 20 ... Transmission audio amplifier 21, 35 ... Transmission noise removing unit 22 ... AD converter 23 ... Transmission data processing unit 24,31 ... Pseudo noise generating unit 25,32 ... Receiving side level adjusting unit 26,33 ... Transmitter level adjuster

Claims (5)

[Claims] 1. A portable communication device for transmitting and receiving an audio signal by wireless communication, comprising: a timing control unit for generating a timing control signal for controlling an intermittent operation of the wireless communication; and the audio signal due to the intermittent operation. A pseudo noise generating means for setting a waveform pattern of a noise component to be superimposed on the audio signal based on the timing control signal, and removing the noise component by subtracting the pseudo noise signal from the audio signal. And a noise removing unit. 2. The timing control signal is a rectangular wave that periodically repeats a high level and a low level in accordance with a state of the intermittent operation. 2. The portable communication device according to claim 1, wherein is set as a waveform pattern. 3. The portable communication apparatus according to claim 1, further comprising: a level adjusting unit that adjusts a level of the pseudo noise signal according to a state of wireless communication and supplies the pseudo noise signal to the noise removing unit. . 4. The reception noise removal means for removing a noise component on a receiving side by subtracting the pseudo noise signal from a reception speech signal, and subtracting the pseudo noise signal from a transmission speech signal. 2. The mobile communication device according to claim 1, further comprising: a transmission noise removing unit that removes a noise component on a transmission side by using the transmission noise removing unit. 5. A receiving-side level adjusting means for performing level adjustment of the pseudo noise signal according to a state of wireless communication and supplying the adjusted level to the reception noise removing means, and a level of the pseudo noise signal according to a state of wireless communication. The mobile communication device according to claim 4, further comprising: a transmission-side level adjustment unit that performs adjustment and supplies the adjustment to the transmission noise removal unit.