JP2000059243A - Communication terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication terminal equipment capable of properly executing voice mute level control according to a communication error state. SOLUTION: A step SA6 following a step SA3 or a step SA4 discriminates whether the number of intermittent receiving errors stored in an error table exceeds the threshold (2) of a level control 4 switching FER(frame error ratio) (step SA6) and in the case of exceeding, starts a level control 4 mute level to control a voice processing part (step SA7). By the processing of this step SA7, A received speech from a speaker is controlled to a level control 4 mute level and when the number of intermittent receiving errors exceeds the threshold (2) of the level control 4 switching FER, the received speech is emitted by a voice easy to hear. Subsequently, the speech processing part is controlled by starting the mute levels of level control 3 to 1 similarly according to the number of the intermittent receiving errors stored in the error table (step SA8 to SA13).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication terminal for controlling a mute level of a received sound.

[0002]

2. Description of the Related Art Heretofore, there has been known a communication terminal which generates a reception sound such as a PHS, for example, which controls a sound mute level of the reception sound. This communication terminal detects the presence or absence of a communication error, activates the audio mute level control when a communication error occurs, and activates the audio mute level control when the communication error is resolved and received normally. , So that the received sound is maintained in an easy-to-hear state.

[0003]

However, in the conventional audio mute level control in a communication terminal, when a communication error is detected even once, the audio mute level control is activated at that time. For this reason, even when an error that does not cause a problem with the call sound occurs, the sound mute level control is activated, and the received sound is rather difficult to hear. Also, if the signal is received even once even during the audio mute level control, the audio mute level control is canceled at that point. Therefore, when the error occurs intermittently, the mute level control is performed. Is repeatedly started and released, so that not only the effect of improving the call sound by the audio mute level control cannot be sufficiently obtained, but also the user's sense of hearing is deteriorated.

Further, regardless of the communication error state, audio mute level control is performed at a predetermined constant mute level. For this reason, if a deep mute level is set, an effective call sound improvement effect can be obtained when there are many errors, but a sufficient effect cannot be obtained when there are few errors, and a shallow mute level is set. Thus, when the error is small, an effective speech sound improving effect can be obtained, but when the error is large, a sufficient improving effect cannot be obtained.

[0005] The present invention has been made in view of such a conventional problem, and has as its object to provide a communication terminal capable of performing appropriate audio mute level control according to a communication error state. Things.

[0006]

According to a first aspect of the present invention, there is provided a communication terminal, comprising: receiving means for receiving a signal; and a receiving means for receiving the signal based on the signal received by the receiving means. Receiving sound generating means for generating a receiving sound, error state detecting means for detecting an error state of the signal, and varying a mute level of the receiving sound generating means in accordance with an error state detected by the error state detecting means And control means for performing dynamic control. Therefore, the mute level of the receiving sound generating means changes at a depth corresponding to the error state of the signal received by the receiving means,
As a result, mute control without excess or deficiency is performed. Therefore, the mute level control that makes the received sound difficult to hear in the error state where there is no problem as the received sound is avoided. Further, since the mute level is variably controlled, the mute level can be controlled at a level corresponding to the error state, and control at an appropriate mute level is possible.

Further, in the communication terminal according to the present invention, the error state detecting means fetches and updates an error state of the signal at the present time, and stores the signal while updating the error state. Thus, the mute level is controlled. Therefore, the mute level control according to the error situation can be performed in real time by the sequentially updated storage contents.

Further, in the communication terminal according to the third aspect, the error state is determined according to a continuous state of the error and the number of errors. Therefore, even before detecting an intermittent error in which a time interval occurs in the detection, the mute level control can be started at an early stage when a continuous error is detected, and a quick response to the error can be achieved. In addition, even when normal reception and error reception are repeated, activation and release of the mute level control are not repeated.

Further, in the communication terminal according to the fourth aspect, the control means sequentially reduces the mute level when releasing the mute level control. Therefore, even when the mute level control is released, the mute level changes successively without abrupt change, so that a sense of hearing without discomfort can be obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the present invention
This is applied to the terminal device. That is, as shown in FIG. 1, the antenna 1 of this terminal is connected to a transmission / reception unit 2, and the transmission / reception unit 2 includes a frequency conversion unit and a modem. On the receiving side, the frequency converter receives the signal input from the antenna 1 via an antenna switch for distributing transmission / reception, and mixes the signal with a local oscillation signal of a predetermined frequency output from the PLL synthesizer. The frequency is converted to an IF signal near 9 GHz. On the transmitting side, the π / 4 shift Q input from the modem
By mixing the PSK modulated wave with a local oscillation signal of a predetermined frequency output from the PLL synthesizer, 1.9 is obtained.
The frequency is converted to a GHz band and radiated from the antenna 1 via the antenna switch. On the receiving side of the modem, the IF signal from the frequency converter is demodulated and separated into IQ data.
The data is transferred to the communication control unit 3 as a data string. On the transmission side, IQ data is created from the data transferred from the communication control unit 3, modulated by π / 4 shift QPSK, and output to the frequency conversion unit.

The communication control unit 3 processes the frame synchronization and the data format of the slot. That is, on the receiving side, data for one slot is taken out at a predetermined timing from the received data sent from the modem of the transmitting / receiving unit 2, and a unique word (synchronization signal) is extracted from this data to obtain frame synchronization. After descrambling the control data section and the audio data section, the control data is sent to the control section 5, and the audio data is transferred to the audio processing section 4. On the transmission side, control data and the like are added to the sound data transferred from the sound processing unit 4 to create the data, and after scrambling and the like, a unique word and the like are added to create transmission data for one slot. At a predetermined timing, it is inserted into a predetermined slot in the frame and transmitted to the modem of the transmission / reception unit 2.

The audio processing unit 4 is composed of a speech codec and a PCM codec. The speech codec performs compression / expansion processing of digital data. On the receiving side, the ADP sent from the communication control unit 3 is used.
CM audio signal (4 bit x 8 kHz = 32 Kbps) to PCM audio signal (8 bit x 8 kHz = 64 Kbps)
And decompressed to output to the PCM codec. On the transmission side, the PCM audio signal transmitted from the PCM codec is encoded into an ADPCM audio signal, compressed and output to the communication control unit 3. P
The CM codec performs an analog / digital conversion process. On the receiving side, the PCM audio signal sent from the speech codec is D / A converted, an analog audio signal is output to the speaker 5, and the control unit 7 is controlled.
The mute level of this analog audio signal is adjusted in accordance with the instruction from. On the transmitting side, the analog audio signal input from the microphone 6 is A / D converted and the PCM audio signal is output to the speech codec.

The control section 7 receives key operation information from a key input section 8 having various keys. The control unit 7 operates based on the key operation information and the program stored in the ROM 9 while using the RAM 10 as a work area, and controls the entire apparatus including the display unit 11 according to a predetermined protocol.

An error table is provided in a part of the RAM 10. This error table is a table in which the oldest reception status is sequentially discarded every 5 ms and updated to the latest reception status, and the error for the latest maximum 640 ms is stored. Then, as shown in FIG. 2A, this error table is reset to “0” when a request for establishing a TCH (channel) from L3 (layer 3) is issued, and the reception status is set from the time of reception of synchronous burst reception ( Error set), and starts monitoring the reception status. Also, as shown in FIG. 2B, the error table is reset to "1" at the time of a TCH switching request from L3 (layer 3) (to improve the voice merit after the switching), and the synchronous burst reception is performed. , The reception status is set (error set) from the time of reception, and monitoring of the reception state is started.

As shown in FIG. 3 (state transition diagram), the ROM 9 includes a mute level used when performing a mute level control at the time of a continuous error, and a mute level used when performing mute level controls 1 to 4 together with a program. Mute levels are stored, and the mute levels used for the mute level controls 1, 2, 3, and 4 are set to be deeper in this order.

The continuous error mute level control is a control started on condition that the number of continuous reception errors in the reception status stored in the error table is equal to or larger than a predetermined number of continuous error switching continuous errors. The mute level control 4 is based on a condition that the number of intermittent reception errors exceeds a level control 4 switching FER (Frame Error Rate) threshold value. Control 3
On condition that the switching FER threshold value is exceeded, the mute level control 2 determines that the number of intermittent reception errors is equal to the level control 2
On condition that the switching FER threshold value is exceeded, the mute level control 1 determines that the number of intermittent reception errors is lower than the level control 1
The control is started on condition that the switching FER threshold value is exceeded. Here, the relationship between the threshold value and the threshold value is <<<<.
That is, the mute level is set to be controlled with a deeper mute as the number of intermittent errors stored in the error table increases.

In this embodiment having the above-described configuration, when a call state is established, the control unit 7 operates according to the mute level control flow shown in FIG. 4 at a timing of 5 ms to update the error table (step S1). SA
1). Next, it is determined whether there is a reception error in the reception status of the error table for the latest maximum 640 ms updated at the timing of 5 ms (step SA2).
If there is no reception error and the reception is OK, the mute level release processing is executed by the current mute method in step SA14 described later.

If there is a reception error and the result is NG, it is determined at this time whether or not any of the mute level controls 1 to 4 is present (step SA3). As a result of this determination, when the state is not in any of the mute level controls 1 to 4, that is, when the mute is in the OFF state or in the continuous error control state, the number of continuous errors in the error table is equal to the continuous error switching continuous error. It is determined whether or not the number is exceeded (step SA4). Then, when the number of continuous error switching continuous errors has been exceeded, the continuous error mute level is activated to control the audio processing unit 4 (step SA5). By the processing in step SA5, the sound from the speaker 5 is controlled to the mute level at the time of a continuous error, and is emitted with a sound that is easy to hear at the time of a continuous error.

Step SA3 or step SA4
In the subsequent step SA6, the number of intermittent reception errors stored in the error table is determined by the level control 4 switching FE.
It is determined whether or not the value exceeds the R threshold (step S
A6) If it exceeds, the level control 4 mute level is activated to control the audio processing unit 4 (step SA7). By the processing in step SA7, the received sound from the speaker 5 is controlled to the level control 4 mute level, and the number of intermittent reception errors is reduced to the level control 4 switching FE.
If the value exceeds the R threshold, the sound is emitted with an easy-to-hear sound.

Similarly, if the result of determination in step SA6 shows that the number of intermittent reception errors stored in the error table does not exceed the level control 4 switching FER threshold, the level control 3 switching It is determined whether or not the FER threshold value is exceeded (step SA8). If the FER threshold value is exceeded, the level control 3 mute level is activated to control the audio processing unit 4 (step SA9). Further, when the threshold value does not exceed the level control 3 switching FER threshold value, it is determined whether the level control 2 switching FER threshold value is exceeded (step SA10). Activate the mute level,
The voice processing unit 4 is controlled (step SA10).

If the level control 2 switching FER threshold is not exceeded, it is determined whether the level control 1 switching FER threshold is exceeded (step SA1).
2) If it exceeds, activate the level control 1 mute level to control the audio processing unit 4 (step SA)
13). However, even if an intermittent reception error has occurred, the level error is determined by the level control 4-1 switching FER threshold value.
If none of the above is exceeded, the process proceeds from step SA12 to another process without executing any level control. Therefore, when the sound mute level control is activated in the error state where there is no problem as the call sound, it is possible to solve the problem that the received sound becomes rather difficult to hear.

The above processing is executed every 5 ms in accordance with the flow shown in FIG. 4, so that a continuous error occurs from the mute OFF state as shown in FIG. When the mute level control is executed (dotted arrow b) and the continuous error state continues, the mute level control is continuously executed at the continuous error (dotted arrow b), and when the state changes from the continuous error state to the intermittent error state, the Mute level controls 1 to 4 are executed according to the number of errors (dotted arrow C). Also, mute O
When an intermittent error occurs from the state of the FF, mute level controls 1 to 4 are executed according to the number of errors (dotted arrow d), and in any of the mute level 1 to 4 control states,
When the number of errors changes, mute levels 1 to 4 are controlled according to the changed number of errors. Therefore, an appropriate mute level control state according to the error state can be obtained, and the effect of improving the call sound without excess or deficiency can be obtained.

On the other hand, the processing for releasing the mute level by the current mute method executed in step SA14 is as follows.
This is performed according to the flow shown in FIG. That is, when the mute method at the present time is a continuous error mute level activation (step SB1), level control 4 mute level activation (step SB4), level control 3 mute level activation (step SB7), level control 2 mute level activation It is determined whether the state is middle (step SB10) or level control 1 mute level is being activated (step SB13).

If the mute level at the time of continuous error is being activated (YES at step SB1), it is determined whether or not it is a predetermined timing to cancel the mute level at the time of continuous error (step SB2). If it is the timing, the mute level at the time of the continuous error is released (step SB3). If the level control 4 mute level is being activated (step SB4 is YE
S), it is determined whether or not it is a predetermined timing to release the level control 4 mute level (step SB).
5) If it is the timing, the level control 4 mute level is released and the level control 3 mute level is activated (step SB6).

Similarly, if the level control 3 mute level is being activated (step SB7 is YES) and it is the predetermined timing to release the level control 3 mute level (step SB8 is YES), the level control 3 If the mute level is released to activate the level control 2 mute level (step SB9), the level control 2 mute level is being activated (step SB10 is YES), and if it is a predetermined timing to release the level control 2 mute level If (Step SB11 is YES), the level control 3 mute level is released and the level control 2 mute level is activated (Step SB12). The level control 1 mute level is being activated (step SB1).
3 is YES, if it is the predetermined timing to release the level control 1 mute level (step SB14).
Is YES), the level control 1 mute level is released (step SB15).

Therefore, the above processing is executed every 5 ms in accordance with the flow shown in FIG. 5, and as shown in FIG. 3, when there is no reception error in the state of continuous error mute level control, as shown in FIG. Is released and the mute is turned off (dotted arrow E). Also,
When there is no reception error in the state of the mute level controls 4 and 2, the processing sequentially shifts to the mute level control 3 to 1 with the shallower mute and the state without the reception error in the state of the mute level control 1 with the shallowest mute. Then, the state returns to the mute OFF state (to the dotted arrow). Therefore, the activation and release of the mute level control are not repeated or the mute level does not change rapidly, but the mute level changes stepwise. Therefore, it is possible to avoid a decrease in the effect of improving the call sound caused by the repeated activation and release of the mute level control and a rapid change in the mute level, and to obtain a sufficient effect of improving the call sound.

Of course, if an error is detected in a state where the mute level is lowered to any one of the level controls 3 to 1 in accordance with this flow, the flow advances from step SA2 to step SA3 in FIG. Is performed. Therefore, a mute level corresponding to the number of reception errors is activated, and therefore, appropriate audio mute level control can always be performed according to the communication error state.

In this embodiment, the audio mute level control is performed in four stages of level control 1 to 4 in accordance with the number of intermittent reception errors. However, the level can be varied in more stages or steplessly. You may make it control.

[0029]

As described above, the present invention detects an error state of a received signal and variably controls a mute level of a received sound in accordance with the detected error state. The mute level of the received sound can be changed to a depth according to the error state,
Appropriate mute control without excess and deficiency becomes possible, and an excellent received sound improvement effect can be obtained.

Further, since the error state at the present time is fetched and stored while being updated, and the mute level is controlled in accordance with the stored contents, mute level control according to the error situation can be performed in real time.

The error state is determined according to the continuous state of errors and the number of errors. Therefore, even before an intermittent error having a time interval to be detected is detected, a continuous error is detected. Mute level control can be started at an early point in time, and even if normal reception and error reception are repeated, activation and release of the mute level control are repeated. There is nothing. Therefore, it is possible to quickly respond to the error, and to avoid a deterioration in the sense of hearing due to the repeated activation and release of the mute level control, and to obtain a sense of hearing without discomfort.

When the mute level control is released, the mute level is sequentially reduced without abrupt change because the mute level is sequentially reduced. Also, it is possible to obtain a sense of hearing without discomfort.

[0033]

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a circuit configuration according to an embodiment of the present invention.

FIG. 2 is a diagram showing a time point at which an error table is reset and a time point at which an error is set in the embodiment.

FIG. 3 is a diagram showing a control operation of the embodiment.

FIG. 4 is a flowchart showing a processing procedure of a control unit in the embodiment.

FIG. 5 is a step SA1 in the flowchart of FIG. 4;
6 is a flowchart showing the contents of processing 4;

[Explanation of symbols]

 2 transmitting / receiving unit 4 audio processing unit 5 speaker 7 control unit

Claims (4)

[Claims] A receiving means for receiving a signal; a receiving sound generating means for generating a receiving sound based on the signal received by the receiving means; an error state detecting means for detecting an error state of the signal; A communication terminal, comprising: control means for variably controlling a mute level of the reception sound generation means according to an error state detected by the error state detection means. 2. The method according to claim 1, wherein the error state detecting means fetches and updates the error state of the signal at the present time and stores the updated state, and the control means controls the mute level in accordance with the stored contents. The communication terminal according to claim 1. 3. The error state according to claim 1, wherein the error state is determined according to a continuous state of the error and the number of errors.
The communication terminal as described. 4. The communication terminal according to claim 1, wherein the control unit sequentially reduces the mute level when canceling the mute level control.