JP3024550B2 - Audio level compensation circuit for mobile terminal equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to terrestrial mobile communication [hereinafter referred to as PDC (Personal Digital).
The present invention relates to a mobile terminal device which can be used in combination with mobile satellite communication and, more particularly, to an audio level compensation circuit of a mobile terminal device which can always receive an appropriate audio level.

[0002]

2. Description of the Related Art In recent years, PDC communication has rapidly spread. Such PDC communication does not cover the entire area on the ground, and the area with low traffic is out of the service range in terms of economy. Thus PDC
Outside of this service range, a method of using both using mobile satellite communication using satellite communication has been considered.

Here, when communication is performed for both PDC communication and mobile satellite communication, a mobile terminal device generally uses a PD.
A transmitting / receiving section for C communication and a transmitting / receiving section for mobile satellite communication. Switching between PDC communication and mobile satellite communication is performed, for example, by transmitting a bit for identifying the both in a transmitted / received signal, There is a method of automatically switching when a is detected. In this case, the voice level diagram often has its own level diagram for each of the PDC communication and mobile satellite communication systems. For this reason,
When the PDC communication of the terminal device and the mobile satellite communication are used together, it is not always possible to obtain the same reception level.
The audio level had to be corrected. In such a case, in order to adjust the reception volume of the voice, the level variable voice volume of the receiving unit is manually changed to adjust the reception volume of the mobile terminal device to an appropriate volume.

[0004]

However, this conventional P
In the method of switching between DC communication and mobile satellite communication using an audio line, there is a problem that the adjustment standard is not clear because the dynamic range of the audio signal is wide and adjustment is difficult. As a result,
When switched, the volume of the voice signal or tone signal heard from the receiver becomes different between the PDC communication and the mobile satellite communication, causing a sense of incongruity.

Accordingly, an object of the present invention is to provide a sound level compensating circuit of a mobile terminal device for PDC communication and mobile satellite communication, which corrects and switches the volume of voice signals and tone signals of PDC communication and mobile satellite communication. The aim is to eliminate discomfort sometimes.

[0006]

A voice level compensating circuit of a mobile terminal device according to the present invention is a voice level compensating circuit of a mobile terminal device that performs communication using both a first communication method and a second communication method. A peak time of a predetermined time based on a detection voltage of a reception voice level demodulated by the first communication method.
First detection and holding means for calculating a level and an average level and holding the calculation result; and a peak for a predetermined time based on a detection voltage of a received voice level demodulated by the second communication method.
A second detection and holding means for calculating a level and an average level and holding the calculation result; and a second communication method or a second communication method from the first communication method based on the first and second detection and holding means. Means for adjusting, when switching from the second communication method to the first communication method, the received audio level to the same level as before the switching. Also,
The first and second communication systems are a mobile satellite communication system and a PDC (Personal Digital Ce), respectively.
(hereinafter referred to as PDC) communication system.
Specifically, in a voice level compensation circuit of a mobile terminal device that performs communication using both PDC communication and mobile satellite communication, a received voice level for mobile satellite communication for detecting a received voice level of the mobile satellite communication. A detection circuit; and the PD
The output of the PDC communication reception voice level detection circuit for detecting the reception voice level of the C communication and the output of the mobile satellite communication reception voice level detection circuit are input, and the peak level and the average level for a predetermined time are calculated. the calculation result and the reception audio processing circuit for mobile satellite communications for holding, receiving the output of the PDC communication received audio level detection circuit for a predetermined time Pikurebe Te
PD that calculates the average level and the average level and retains the calculation result
A reception audio processing circuit for C communication, a first level adjustment circuit for adjusting the reception audio level of the PDC communication, a second level adjustment circuit for adjusting the reception audio level of the mobile satellite communication, and the PDC communication The first and second level adjustments are performed such that the received voice level of the communication side selected based on the control voltage for selecting whether the received voice level is the same as the received voice level of the communication side before being selected. A reception audio level control circuit for controlling a circuit, and a reception audio selection circuit for receiving an output of the first and second level adjustment circuits and switching to an output of a predetermined level adjustment circuit based on the control voltage.

[0007] In a wireless device capable of performing both mobile satellite communication and PDC communication, the mobile satellite communication and PDC communication can be performed during a call.
When the DC communication is switched in the middle, the received voice level before the switching is detected and held, and the gain of the received voice level after the switching is adjusted. The sound volume of the received voice and the tone of the satellite communication can be corrected, and the discomfort can be eliminated when switching between the PDC communication and the mobile satellite communication.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a portion related to a receiving unit level correction, particularly in a configuration of a mobile terminal device according to the present invention.

Now, when mobile satellite communication is used, the demodulated received voice signal is input to an input terminal 1, and a received voice level detection circuit 3 and a received voice level gain adjustment circuit 2
Is branched into two. The reception audio level detection circuit 3 has a function of detecting the reception audio level.

The detection voltage detected by the reception sound level detection circuit 3 is input to the reception sound processing circuit 4.

The reception audio processing circuit 4 calculates the maximum, minimum and average voltages of the detection voltage from the reception audio level detection circuit 3 for a predetermined time, and stores these calculated values indicating the characteristics of the reception audio level. Has functions. These represent the peak level and the average level of the reception level within a predetermined time.

The calculated values stored in the reception voice processing circuit 4 store the long-term reception average level and peak level by repeating the same calculation according to the sequentially input detection voltage. Next, the stored reception average level and peak level are input to the reception voice level control circuit 14.

On the other hand, when the PDC communication is used, the received voice signal is input to the input terminal 10 and is divided into a received voice level detection circuit 11 and a received voice level gain adjustment circuit 13 as in the case of the mobile satellite communication. Is done. The detection output of the reception audio level detection circuit 11 is processed by the reception audio processing circuit 12, and the average reception level and the like are output to the reception audio level control circuit 14.

The received voice level control circuit 14 receives the output voltage and the control voltage 17 of both the received voice processing circuits 4 and 12 for mobile satellite communication and PDC communication.

Here, the control voltage 17 is a signal indicating whether the mobile satellite communication is being received or the PDC communication is being received.

The output of the reception voice level control circuit 14 outputs a gain variable control signal to the reception voice level adjustment circuit 2 to control the reception level on the mobile satellite communication side during communication, and outputs the PDC signal during PDC communication. A gain variable control signal is output to the reception audio level adjustment circuit 13 to control the reception level on the communication side.

The received audio level gain adjustment circuit 2
Each of the circuits 13 can be simply constituted by an amplifier or a variable attenuator whose gain can be varied by a gain varying control signal of the received voice level control circuit 14.

For example, there is a method of controlling the attenuation of the variable attenuator by applying a DC voltage from the output of the reception voice level control circuit 14 and varying the drive current of the pin diode.

The outputs of the received voice level adjustment circuit 2 and the received voice level adjustment circuit 13 are input to a received voice selection circuit 15 and the output of the received voice level gain adjustment circuit 2 is selected based on the control signal 17 during mobile satellite communication. During PDC communication, the output of the received voice level gain adjustment circuit 13 is selected and output to the output terminal 16 respectively.

A more specific operation will be described below.

It is assumed that the power of the mobile terminal device is turned on and communication is performed with either PDC communication or mobile satellite communication. At this time, each circuit shown in FIG. 1 is reset, and the internal received voice processing circuits 4 and 12 are in a state where no data is held. Then, it is assumed that communication is first performed by PDC communication. The received voice signal for PDC communication is input to an input terminal 10 and is divided into two parts, a received voice level detection circuit 11 and a received voice level gain adjustment circuit 13. The output of the received voice level detection circuit 11 is input to the received voice processing circuit 12, and the calculated value of the received voice is output to the received voice level control circuit 14. Also,
At this time, the input terminal 1 of the receiving voice input terminal for mobile satellite communication
Since no mobile satellite communication is performed, nothing is input, and the received voice level detection circuit 3 detects a silent level and outputs it to the received voice processing circuit 4. The reception audio processing circuit 4 stores the silence level and outputs it to the reception audio level control circuit 14. The output of the received voice processing circuits 4 and 12 is input to the received voice level control circuit 14. Here, the average PDC communication reception level is used to set the gain of the mobile satellite communication reception voice level, while the average mobile satellite communication reception level is used to set the gain of the PDC communication reception voice. Now, in this example, since PDC communication is performed, P
After the received voice of the DC communication is input to the input terminal 10, the received voice level detection circuit 11, the received voice level adjustment circuit 1
3 is not adjusted since the power is turned on, and the audio level is output to the reception audio selection circuit 15 as it is.
Output to

Here, assuming that the switching from the PDC communication to the mobile satellite communication is performed, the received voice changes from the PDC communication received voice to the mobile satellite communication received voice, and the input terminal 1
, The voice received from the mobile satellite communication is input. The received audio signal input to the input terminal 1 is split into two parts, a received audio level detection circuit 3 and a received audio level gain adjustment circuit. The output of the reception audio level detection circuit 3 is input to the reception audio processing circuit 4 and held. Further, the received voice input to the received voice level gain adjustment circuit 2 is gain-adjusted from the received voice level control circuit based on the received voice level when PDC communication is being performed.

FIG. 2 is a diagram for explaining the operation of the present invention.

In this figure, it is assumed that the gain of the received voice level gain adjustment circuit 13 is G ₁ during PDC communication. The average value of the received audio level by the reception processing unit 12 in this case is assumed to be V _m.

Next, at time t ₀ when the Tsu conversion over to mobile satellite communications from the PDC communication, the reception voice level control circuit 14, the received audio level gains 2 so as to be V _m stored in PDC communication to set the gain to G _2.

As a result, even if the communication is changed from the PDC communication to the mobile satellite communication, it is possible to receive at the same reception level.

As a result, at the time of switching between PDC communication and mobile satellite communication, the volume of the voice signal or tone signal can be corrected, and the sense of discomfort can be eliminated.

[0029]

As described above, the mobile terminal apparatus according to the present invention, when switching from PDC communication to mobile satellite communication or from mobile satellite communication to PDC communication, sets the average received voice level before switching communication. By adjusting the gain of the received voice signal level after switching based on the detected and held value, an effect of eliminating a sense of incongruity when switching between PDC communication and mobile satellite communication can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 reception audio input terminal for mobile satellite communication 2 reception audio level gain adjustment circuit 3 reception audio level detection circuit 4 reception audio processing circuit 10 reception audio input terminal for PDC communication 11 reception audio level detection circuit 12 reception audio processing circuit 13 reception audio Level gain adjustment circuit 14 Reception audio level control circuit 15 Reception audio selection circuit 16 Reception audio output terminal 17 Control signal

────────────────────────────────────────────────── ─── front page continued (51) Int.Cl. ⁷ identifications FI H04Q 7/38 H04B 7/26 109G (56 ) references Patent Rights 7-59162 (JP, a) JP Akira 58-168396 ( JP, A) JP-A-1-319354 (JP, A) JP-A-6-78033 (JP, A) JP-A-2-214338 (JP, A) JP-A-6-54045 (JP, A) JP JP-A-8-242279 (JP, A) JP-A-6-318902 (JP, A) JP-A-6-338849 (JP, A) Jpn. .Cl. ⁷ , DB name) H04M 1/60 H04B 7/26 H04M 1/725 H03G 3/20-3/34 H04Q 7/38

Claims (3)

(57) [Claims] An audio level compensating circuit for a mobile terminal device that performs communication by using both a first communication system and a second communication system, wherein a detection of a received audio level demodulated by the first communication system is performed.
Measures the peak level and average level for a predetermined time based on the voltage
First detection and holding means for calculating and holding the calculation result, and detecting the received voice level demodulated by the second communication method
Measures the peak level and average level for a predetermined time based on the voltage
Second detection and holding means for calculating and holding the calculation result, and the first communication method to the second communication method or the second communication based on the first and second detection and holding means. Means for adjusting the received audio level to be the same as the level before switching when the system is switched from the first communication system to the first communication system. 2. The first and second communication systems are respectively a mobile satellite communication system and a PDC (Personal Diel).
(digital cellular, hereinafter referred to as PDC) communication system. 3. An audio level compensating circuit for a mobile terminal device for performing communication using both PDC communication and mobile satellite communication, wherein a received audio level for mobile satellite communication for detecting a received audio level of the mobile satellite communication. A detection circuit, a reception audio level detection circuit for PDC communication for detecting the reception audio level of the PDC communication, and an output of the reception audio level detection circuit for the mobile satellite communication, and calculating a peak level and an average level for a predetermined time A receiving voice processing circuit for mobile satellite communication that holds the calculation result, and an output of the receiving voice level detection circuit for PDC communication, and calculates a peak level and an average level for a predetermined time, and holds the calculation result. A receiving voice processing circuit for PDC communication, a first level adjusting circuit for adjusting a receiving voice level of the PDC communication, and a receiving level for the mobile satellite communication. A second level adjusting circuit for adjusting an audio level; and a reception audio level on the communication side selected based on a control voltage for selecting the PDC communication or the mobile satellite communication and reception on the communication side before being selected. A reception audio level control circuit for controlling the first and second level adjustment circuits so as to make the audio level the same, and a predetermined level based on the control voltage in response to the output of the first and second level adjustment circuits An audio level compensation circuit for a mobile terminal device, comprising: a reception audio selection circuit that switches to an output of an adjustment circuit.