JP6730591B2 - Wireless communication device and communication control method - Google Patents

Description

The present invention relates to a wireless communication device having a noise canceling function and a squelch function and a communication control method.

A wireless communication device has a noise canceling function that suppresses noise components in the demodulated signal and a squelch that shuts off somewhere in the section from the demodulator to the speaker when there is a large amount of noise in the received signal to put it into a silent state. There is a function.

Patent Document 1 discloses a receiving device that can easily and appropriately set a squelch level.

JP2012-95365A

In a wireless communication device equipped with a squelch function as described in Patent Document 1, a user can set a threshold value (squelch sensitivity) at which noise level is used to switch on/off of audio output. On the other hand, the noise canceling function of the wireless communication device suppresses the noise component in the demodulated signal by about 1 to 3 dB and improves the sound quality. The noise cancellation performed does not affect the reception sensitivity of the wireless signal. Therefore, in a wireless communication device having both a noise canceling function and a squelch function, even if the noise canceling function works to improve the auditory reception sensitivity, the reception sensitivity of the wireless signal is poor and the noise level is near the squelch sensitivity. In this case, the noise level may exceed the threshold and the audio output may be turned off (squelch closed). In this case, the perceptual reception sensitivity feels the same as when the noise cancellation is not working.

The present invention has been made in view of the above problems, and in a wireless communication device having a noise canceling function and a squelch function, despite the fact that the noise canceling function works and the receiving sensitivity is good in hearing, The purpose is to prevent the squelch from closing near the squelch sensitivity.

In order to achieve the above object, the wireless communication device according to the first aspect of the present invention,
A wireless communication device having a squelch function and a noise canceling function,
A frequency conversion unit that performs frequency conversion of the reception signal captured by the antenna and outputs an IF signal that is an intermediate frequency signal,
A demodulation unit that demodulates the IF signal and outputs a demodulated signal;
An extraction unit that outputs a noise signal in which only a noise component is extracted from the demodulated signal output by the demodulation unit,
When the noise canceling function is on, a noise canceling unit that generates a noise canceling signal that suppresses noise components of the demodulated signal output by the demodulating unit,
When the noise canceling function is off, the demodulated signal is output by voice, and when the noise canceling function is on, an output unit that outputs the noise canceling signal by voice,
When the squelch function is on, when the voltage value indicated by the noise signal output by the extraction unit becomes equal to or higher than the first threshold value, the audio output of the output unit is stopped, and the voltage value indicated by the noise signal becomes the second value. A squelch control unit that permits the voice output of the output unit when it is less than a threshold value,
Equipped with
The first threshold value and the second threshold value when the noise canceling function is on are respectively set to values larger than the first threshold value and the second threshold value when the noise canceling function is off. ing.

Preferably, the first threshold value is set to a value larger than the second threshold value.

Preferably, the first threshold and the second threshold are set for each squelch level, and as the squelch level increases, the values of the first threshold and the second threshold decrease, and The difference between the first threshold value and the second threshold value is set to be large.

A communication control method according to a second aspect of the present invention is
A communication control method performed by a wireless communication device having a squelch function and a noise canceling function,
A frequency conversion step of performing frequency conversion of the reception signal captured by the antenna and outputting an IF signal which is a signal of an intermediate frequency;
A demodulation step of demodulating the IF signal and outputting a demodulated signal;
An extraction step of outputting a noise signal in which only a noise component is extracted from the demodulated signal output in the demodulation step,
When the noise canceling function is on, a noise canceling step of generating a noise canceling signal in which a noise component of the demodulated signal output in the demodulating step is suppressed,
An output step of outputting the demodulated signal as voice when the noise canceling function is off, and outputting the noise canceling signal as voice when the noise canceling function is on,
When the squelch function is on, when the voltage value indicated by the noise signal output in the extraction step becomes equal to or higher than the first threshold value, the audio output in the output step is stopped and the voltage value indicated by the noise signal becomes the second value. And a squelch control step that permits the audio output in the output step when it is less than the threshold value of
Equipped with
The first threshold value and the second threshold value when the noise canceling function is on are respectively set to values larger than the first threshold value and the second threshold value when the noise canceling function is off. ing.

According to the present invention, in a wireless communication device having a noise canceling function and a squelch function, it is possible to prevent the squelch from closing near the squelch sensitivity even though the noise canceling function works and the receiving sensitivity is good in hearing. It is possible.

It is a block diagram which shows the structural example of the radio|wireless communication apparatus which concerns on embodiment of this invention. It is a block diagram showing an example of functional composition of a radio communications equipment concerning an embodiment. It is a figure which shows an example of the squelch level table which concerns on embodiment. 6 is a flowchart showing an example of an operation of a reception process according to the embodiment. 6 is a flowchart showing an example of operation of squelch control processing according to the embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent parts are designated by the same reference numerals.

FIG. 1 is a block diagram showing a configuration example of a wireless communication device according to an embodiment of the present invention. The wireless communication device 1 includes an IF-IC 11, a squelch adjuster 12, a buffer amplifier 13, a TX/RX switch 14, a noise canceling IC 15, a mute switch 16, a low pass filter 17, an AF volume 18, an AF amplifier 19, a noise amplifier 20, a CPU 21, A microphone amplifier 22, a mute switch 23, a microphone adjuster 24, a limiter 25, a low-pass filter 26, an AF amplifier 27 and a frequency converter 28 are provided.

The IF-IC 11 frequency-converts the reception signal captured by the antenna to generate an IF (Intermediate Frequency) signal. The IF-IC 11 demodulates the IF signal to generate a demodulated signal and sends it to the squelch adjuster 12. The squelch adjuster 12 attenuates the demodulated signal received from the IF-IC 11 to an appropriate signal level. IF-IC 11 is provided with a band-pass filter, and outputs the noise signal only noise component is extracted from the demodulated signal squelch adjuster 12 has output is sent to a noise amplifier 20. The noise amplifier 20 amplifies the noise signal received from the IF-IC 11 to an appropriate signal level and sends it to the CPU 21.

The buffer amplifier 13 amplifies the demodulated signal generated by the IF-IC 11 to an appropriate signal level. The TX/RX switch 14 is a switch for switching between transmission and reception, and sends the demodulated signal output from the buffer amplifier 13 to the noise canceling IC 15 during reception. When the noise canceling function is on, the noise canceling IC 15 generates a noise canceling signal in which the noise component of the demodulated signal received from the TX/RX switch 14 is suppressed. The noise canceling IC 15 sends the generated noise canceling signal to the mute switch 16. When the noise canceling function is off, the noise canceling IC 15 sends the demodulated signal received from the TX/RX switch 14 to the mute switch 16 as it is. When the mute switch 16 is closed (when the squelch is open), the noise cancellation signal or the demodulation signal is sent to the low pass filter 17.

The low-pass filter 17 removes unnecessary high frequency components from the noise cancel signal or the demodulated signal received from the noise cancel IC 15 and sends them to the AF volume 18. The AF volume 18 adjusts the volume of the noise cancellation signal or the demodulation signal received from the low-pass filter 17, and sends it to the AF amplifier 19. The AF amplifier 19 amplifies the noise cancel signal or the demodulated signal received from the AF volume 18 to an appropriate signal level and sends the amplified signal to the speaker. The speaker outputs the noise cancellation signal or the demodulation signal received from the AF amplifier 19 as a voice.

When the squelch function is ON, the CPU 21 opens the mute switch 16 (closes the squelch) when the voltage value of the noise signal received from the noise amplifier 20 is equal to or higher than the first threshold value, and when the voltage value is less than the second threshold value, the mute switch 16 is activated. Control (open squelch). When the noise canceling function is on, the CPU 21 sets the first threshold value and the second threshold value to larger values than when the noise canceling function is off. When the squelch function is off, the CPU 21 does not control opening/closing of the mute switch 16, and the mute switch 16 is closed (squelch is open). Alternatively, the squelch function may be always on.

The microphone amplifier 22 acquires a sound collection signal obtained by converting the sound collected by the microphone into an electric signal and amplifies it to an appropriate signal level. The TX/RX switch 14 sends the sound collection signal output from the microphone amplifier 22 to the mute switch 23 during transmission. When the mute switch 23 is closed, the sound collection signal is sent to the microphone adjuster 24. The microphone adjuster 24 attenuates the sound collection signal received from the mute switch 23 to an appropriate signal level. The limiter 25 limits the amplitude of the sound collection signal attenuated by the microphone adjuster 24 so as to be constant, and sends it to the low-pass filter 26. The low-pass filter 26 removes unnecessary high-frequency components from the sound collection signal received from the limiter 25 and sends it to the AF amplifier 27. The AF amplifier 27 amplifies the sound collection signal received from the low-pass filter 26 to an appropriate signal level and sends it to the frequency conversion unit 28. The frequency conversion unit 28 modulates a carrier wave generated by a local oscillator (not shown) with a sound collection signal to generate a transmission signal. The transmission signal generated by the frequency conversion unit 28 is transmitted from the antenna.

FIG. 2 is a block diagram showing a functional configuration example of the wireless communication device according to the embodiment of the present invention. The wireless communication device 1 includes a frequency conversion unit 31, a demodulation unit 32, an extraction unit 33, a noise cancellation unit 34, an output unit 35, a squelch control unit 36, and a transmission unit 37 as a functional configuration. The frequency conversion unit 31 frequency-converts a reception signal input from the antenna to generate an IF signal. The IF-IC 11 in FIG. 1 functions as the frequency conversion unit 31. The demodulation unit 32 demodulates the IF signal generated by the frequency conversion unit 31 to generate a demodulation signal. The demodulation unit 32 sends the generated demodulation signal to the extraction unit 33 and the noise cancellation unit 34. The IF-IC 11 and the buffer amplifier 13 in FIG. 1 function as the demodulation unit 32.

The extraction unit 33 extracts a noise signal from the demodulated signal received from the demodulation unit 32 and sends it to the squelch control unit 36. The IF-IC 11, the squelch adjuster 12, and the noise amplifier 20 in FIG. 1 function as the extraction unit 33. When the noise canceling function is on, the noise canceling unit 34 generates a noise canceling signal in which the noise component of the demodulated signal received from the demodulating unit 32 is suppressed. The noise canceling unit 34 sends the generated noise canceling signal to the output unit 35. When the noise canceling function is off, the noise canceling unit 34 sends the demodulated signal received from the demodulating unit 32 to the output unit 35. The noise canceling IC 15 of FIG. 1 functions as the noise canceling unit 34. When the noise canceling function is on, the output unit 35 adjusts the noise canceling signal received from the noise canceling unit 34 and outputs the sound through the speaker. When the noise canceling function is off, the output unit 35 adjusts the demodulated signal received from the noise canceling unit 34 and outputs the sound through the speaker. The low-pass filter 17, the AF volume 18, and the AF amplifier 19 in FIG. 1 function as the output unit 35.

When the squelch function is on, the squelch control unit 36 stops the voice output of the output unit 35 (closes the squelch) when the voltage value of the noise signal received from the extraction unit 33 becomes equal to or higher than the first threshold value, and the second squelch function is performed. When it is less than the threshold value, control is performed to permit the audio output of the output unit 35 (open the squelch). When the squelch function is off, the squelch control unit 36 does not control the audio output of the output unit 35. The CPU 21 and the mute switch 16 in FIG. 1 function as the squelch control unit 36. The squelch control unit 36 stores a squelch level table indicating the first threshold value and the second threshold value when the noise cancellation function is on and the first threshold value and the second threshold value when the noise cancellation function is off. The output unit 35 is controlled with reference to this. Here, the squelch level table stored in the squelch control unit 36 will be described with reference to FIG.

FIG. 3 is a diagram showing an example of a squelch level table according to the embodiment. In the squelch level table of FIG. 3, the squelch level LV. 1-LV. 10 is set. The higher the squelch level, the more difficult it is to open the squelch (the first threshold and the second threshold are smaller), and the lower the squelch level is, the easier the squelch is opened (the first threshold and the second threshold increase. ). “Open” indicates the second threshold value during normal standby when the noise canceling function is off. In the example of FIG. 3, the LV. The set value of 1 is the voltage value of the noise signal when the test radio signal of the power level “−14 dBu” is input, and the LV. The set value of 10 is the voltage value of the noise signal when the test wireless signal of the power level “−4 dBu” is input. "Open" squelch level LV. 2 to LV. The setting value of 9 is LV. 1 and the LV. Values between the set values of 10 are distributed at equal intervals.

“Open Scan” indicates the second threshold value during the scan operation in which the wireless communication device 1 causes the reception frequency to transition within a predetermined band when the noise canceling function is off. At the same squelch level, the second threshold value of “Open Scan” is larger than the second threshold value of “Open” so that the squelch can be opened more easily during the scan operation than during the normal standby. “Close” indicates the first threshold value during normal standby when the noise canceling function is off. “Open (NC)” indicates the second threshold value during normal standby when the noise canceling function is on. “Close (NC)” indicates the first threshold value during normal standby when the noise canceling function is on. The values of “Open (NC)” and “Close (NC)” at the same squelch level are “Open” and “Open” so that the squelch is easier to open when the noise cancel function is on than when it is off. The value is larger than the value of “Close”.

Hereinafter, the values of "Open" and "Close" will be referred to as threshold values when noise cancellation is off, and the values of "Open (NC)" and "Close (NC)" will be referred to as threshold values when noise cancellation is on. In the squelch level table of FIG. 3, regarding the threshold value when noise cancellation is off and the threshold value when noise cancellation is on, the second threshold value is larger than the first threshold value at the same squelch level. In this way, by making a certain difference between the first threshold value and the second threshold value, it is possible to prevent the squelch from repeatedly opening and closing (fluttering) near the threshold value. Note that the higher the squelch level, the smaller the noise is used to control the opening and closing of the squelch. Therefore, in the example of FIG. 3, as the squelch level increases, the difference between the first threshold value and the second threshold value becomes larger (battery). In order to prevent the noise cancellation), a threshold value when noise cancellation is turned off and a threshold value when noise cancellation is turned on are set.

The transmitter 37 of FIG. 2 adjusts the sound collection signal input from the microphone and frequency-converts it to generate a transmission signal. The transmitter 37 transmits the generated transmission signal via the antenna. The microphone amplifier 22, the microphone adjuster 24, the limiter 25, the low-pass filter 26, the AF amplifier 27, and the frequency conversion unit 28 in FIG. 1 function as a transmission unit 37. Here, the operation of the reception process executed by the wireless communication device 1 will be described with reference to FIG.

FIG. 4 is a flowchart showing an example of the operation of the reception process according to the embodiment. The reception process starts when the wireless communication device 1 is activated. When the reception signal is not acquired from the antenna (step S11; NO), the frequency conversion unit 31 of the wireless communication device 1 repeats the process of step S11 and waits for acquisition of the reception signal. When the reception signal is acquired from the antenna (step S11; YES), the frequency conversion unit 31 frequency-converts the reception signal to generate an IF signal (step S12). The demodulation unit 32 demodulates the IF signal generated by the frequency conversion unit 31 to generate a demodulation signal (step S13). The demodulation unit 32 sends the generated demodulation signal to the extraction unit 33 and the noise cancellation unit 34.

The extraction unit 33 extracts a noise signal from the demodulated signal received from the demodulation unit 32 (step S14) and sends it to the squelch control unit 36. The squelch control unit 36 performs squelch control processing for controlling the opening and closing of the squelch based on the noise signal received from the extraction unit 33 (step S15). When the noise canceling function is on (step S16; YES), the noise canceling section 34 generates a noise canceling signal in which the noise component of the demodulated signal received from the demodulating section 32 is suppressed (step S17). The noise canceling unit 34 sends the generated noise canceling signal to the output unit 35. When the squelch is opened by the squelch control process of step S15 (step S18; YES), the output unit 35 adjusts the noise cancel signal received from the noise cancel unit 34 and outputs the sound through the speaker (step S19). ), the processing ends. When the squelch is closed by the squelch control processing in step S15 (step S18; NO), the processing ends.

On the other hand, when the noise canceling function is off (step S16; NO), the noise canceling unit 34 sends the demodulated signal received from the demodulating unit 32 to the output unit 35. When the squelch is opened by the squelch control processing in step S15 (step S20; YES), the output unit 35 adjusts the demodulated signal received from the noise canceling unit 34 and outputs the sound through the speaker (step S21). , The process ends. When the squelch is closed by the squelch control processing in step S15 (step S20; NO), the processing ends. Next, the squelch control processing defined in step S15 will be described with reference to FIG.

FIG. 5 is a flowchart showing an example of the operation of the squelch control processing according to the embodiment. When the noise canceling function is on (step S31; YES), the squelch control unit 36 of the wireless communication device 1 refers to the threshold value when the noise canceling is turned on in the squelch level table as shown in FIG. 3 (step S32). When the noise canceling function is off (step S31; NO), the squelch control unit 36 refers to the threshold value when noise canceling is off in the squelch level table as shown in FIG. 3 (step S33).

When the voltage value of the noise signal received from the extraction unit 33 is equal to or higher than the first threshold value (step S34; YES), the squelch control unit 36 stops the voice output of the output unit 35 and closes the squelch (step S35). ), the processing ends. When the voltage value of the noise signal received from the extraction unit 33 is less than the first threshold value (step S34; NO), the squelch control unit 36 determines that the voltage value of the noise signal is less than the second threshold value (step S36). ; YES), the audio output of the output unit 35 is permitted, the squelch is opened (step S37), and the process is ended. If the voltage value of the noise signal is greater than or equal to the second threshold value (step S36; NO), the process ends.

As described above, according to the wireless communication device 1 having the noise canceling function and the squelch function according to the embodiment, even though the noise canceling function works and the receiving sensitivity is good in hearing, the squelch is generated near the squelch sensitivity. It is possible to suppress closing.

The embodiment of the present invention is not limited to the above embodiment. The configuration of the wireless communication device 1 in the above-described embodiment is an example, and for example, the wireless communication device 1 may be a transceiver having a transmission/reception function, or may have only a reception function. When the wireless communication device 1 has only the reception function, the TX/RX switch 14, the microphone amplifier 22, the mute switch 23, the microphone adjuster 24, the limiter 25, the low-pass filter 26, the AF amplifier 27, and the frequency conversion unit 28 in FIG. The transmitter 37 in FIG. 2 may be omitted. The antenna, the microphone, and the speaker may be built in the wireless communication device 1 or may be external devices. The first threshold and the second threshold may be the same value.

1 wireless communication device 11 IF-IC
12 Squelch adjuster 13 Buffer amplifier 14 TX/RX switch 15 Noise canceling IC
16 Mute Switch 17 Low Pass Filter 18 AF Volume 19 AF Amplifier 20 Noise Amplifier 21 CPU
22 Microphone Amplifier 23 Mute Switch 24 Microphone Adjuster 25 Limiter 26 Low Pass Filter 27 AF Amplifier 28 Frequency Converter 31 Frequency Converter 32 Demodulator 33 Extractor 34 Noise Canceler 35 Output 36 Squelch Control 37 Transmitter

Claims (4)

A wireless communication device having a squelch function and a noise canceling function,
A frequency conversion unit that performs frequency conversion of the reception signal captured by the antenna and outputs an IF signal that is an intermediate frequency signal,
A demodulation unit that demodulates the IF signal and outputs a demodulated signal;
An extraction unit that outputs a noise signal in which only a noise component is extracted from the demodulated signal output by the demodulation unit,
When the noise canceling function is on, a noise canceling unit that generates a noise canceling signal that suppresses noise components of the demodulated signal output by the demodulating unit,
When the noise canceling function is off, the demodulated signal is output by voice, and when the noise canceling function is on, an output unit that outputs the noise canceling signal by voice,
When the squelch function is on, when the voltage value indicated by the noise signal output by the extraction unit becomes equal to or higher than the first threshold value, the audio output of the output unit is stopped, and the voltage value indicated by the noise signal becomes the second value. A squelch control unit that permits the voice output of the output unit when it is less than a threshold value,
Equipped with
The first threshold value and the second threshold value when the noise canceling function is on are respectively set to values larger than the first threshold value and the second threshold value when the noise canceling function is off. Wireless communication device. The wireless communication device according to claim 1, wherein the first threshold value is set to a value larger than the second threshold value. The first threshold value and the second threshold value are set for each squelch level, and as the squelch level increases, the first threshold value and the second threshold value decrease, and the first threshold value and the second threshold value decrease. The wireless communication device according to claim 2, wherein the difference between the threshold value and the second threshold value is set to be large. A communication control method performed by a wireless communication device having a squelch function and a noise canceling function,
A frequency conversion step of performing frequency conversion of the reception signal captured by the antenna and outputting an IF signal which is a signal of an intermediate frequency;
A demodulation step of demodulating the IF signal and outputting a demodulated signal;
An extraction step of outputting a noise signal in which only a noise component is extracted from the demodulated signal output in the demodulation step,
When the noise canceling function is on, a noise canceling step of generating a noise canceling signal in which a noise component of the demodulated signal output in the demodulating step is suppressed,
An output step of outputting the demodulated signal as voice when the noise canceling function is off, and outputting the noise canceling signal as voice when the noise canceling function is on,
When the squelch function is on, when the voltage value indicated by the noise signal output in the extraction step becomes equal to or higher than the first threshold value, the audio output in the output step is stopped and the voltage value indicated by the noise signal becomes the second value. And a squelch control step that permits the audio output in the output step when it is less than the threshold value of
Equipped with
The first threshold value and the second threshold value when the noise canceling function is on are respectively set to values larger than the first threshold value and the second threshold value when the noise canceling function is off. Communication control method.

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