JP2001008257A - Mobile radio terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the user-friendliness by extending the call area of a mobile radio terminal. SOLUTION: The mobile radio terminal is provided with a channel quality estimating section 1-8 that monitors the error status of a received frame for estimating the status of channels and with a voice quality improving section 1-9 that conducts prescribed processing, on the basis of the estimate result by the channel quality estimate section 1-8 to improve the voice quality. When the channel quality estimating section 1-8 discriminates that the terminal is located outside of a communication zone, the voice quality improvement section 1-9 is controlled so as to output only the noise. When the channel quality estimate section 1-8 discriminates that the terminal is resident around the outside of the communication zone, the voice quality improvement section 1-9 is controlled to output a signal with a background noise superimposed thereon. Strong error correction is applied only to control data of a transmitted frame, and the terminal can be controllable even on the verge of the out-zone where data cannot received correctly be and no reconnection or the like is required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile radio terminal such as a PHS, a portable telephone, a cordless telephone and the like.

[0002]

2. Description of the Related Art Numerous applications have been filed for PHS, portable telephones and cordless telephones. For example, regarding the frequency and channel switching method in cordless telephones,
JP-A-5-284108 and JP-A-6-315008 disclose a method of adding background noise to a method of adding a background noise.
No. 208, JP-A-6-125273, JP-A-7-50
No. 631, JP-A-7-160294, JP-A-7-16
2362, JP-A-8-163394, JP-A-8-3
No. 21811 and Japanese Patent Application Laid-Open No. 10-145261 disclose displaying communication quality.
And JP-A-9-135203.

[0003]

[Problems to be Solved by the Invention] In a public network, QoS (Quali
ty of service) must be kept above a certain level.
For example, in PHS, handover and forced disconnection prevent voice communication from taking place in a poor environment. On the other hand, in an indoor digital wireless voice communication system without a network, to expand the communication area as much as possible,
It is necessary to maintain a call even when the voice quality is lower than that of a public network.

The frame includes a preamble (1) for the receiving circuit to perform bit synchronization with the received frame, a unique word (2) for the bit-synchronized receiving circuit to further perform frame synchronization, control data (3), It comprises audio data (4) and parity (5) for error control. In the related art, error correction is commonly performed on (3) and (5), and strong correction is performed on (5).

However, in this system, the following problems are likely to occur in the case of a home telephone or the like. If the audio data and the control data are the same or perform strong encoding on the audio, the control data cannot be exchanged at the same time as or sooner when the audio data cannot be communicated in the case of fringe or shadowing, It becomes necessary to reconnect. In such a case, reconnection often takes time.

Further, in an indoor digital wireless voice communication system without a network, it is required to notify the user of the status of the line quality and change the position of the terminal as necessary. For that purpose, it is necessary to use a LCD, LED, or the like as a visual element to provide a user with easy-to-understand channel switching time, or to display the use status on the LCD by measuring the use state.

An object of the present invention is to provide a mobile radio terminal device suitable for an indoor digital radio voice communication system without a network.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a line quality estimating section for estimating a line state by monitoring an error state of a received frame, and an estimation by the line quality estimating section. A voice quality improvement unit that performs predetermined processing based on the result to improve voice quality, and when it is determined that the communication quality is out of the communication range by the channel quality estimation unit, the voice quality improvement unit outputs only noise, When the estimation unit determines that the area is outside the communication range, the voice quality improvement unit superimposes background noise on the signal and outputs the signal.

According to the present invention, with the above-described configuration, the communication area can be expanded, and the convenience of the user can be improved.

Preferably, the line quality estimating unit includes: an error detector for detecting an error in received data; a long section error counter for counting errors for a predetermined long section based on an output of the error detector; By comparing a short section error counter for counting errors for a predetermined short section based on the output of the detector and an output of the long section error counter and / or an output of the short section error counter with a predetermined threshold value, the line quality is improved. And a determination circuit for estimating.

Preferably, the short-term error counter comprises:
In order to determine short-term line quality deterioration including fading and shadowing, a moving average of errors is obtained in a short section, and the long-term error counter is used to determine an error in a long section in order to judge out of service. Find the moving average.

Preferably, the apparatus further includes a line quality status detecting section for detecting a status of the channel quality based on the estimation result by the channel quality estimating section, and a display section for displaying the channel quality based on the channel quality status detecting section.

Preferably, a channel quality improvement method estimator for estimating a channel quality improvement method based on an estimation result by the channel quality estimator, and a display for displaying a channel quality improvement method based on the channel quality improvement method estimator. Unit.

According to the present invention, when transmitting a frame including a preamble, a unique word, control data, audio data, and an error control code, an error control code for only the control data is generated, and this is included in the control data. It is characterized by including an error control unit for additionally transmitting.

According to the present invention, even when audio data cannot be correctly received, control data can be correctly received with a strong error correction capability. Therefore, the communication area can be expanded more than before.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention relate to an indoor digital radio voice communication system. FIG. 1 is a schematic block diagram of a wireless mobile terminal device according to an embodiment of the present invention, and FIG. 2 is a schematic operation flowchart thereof.

Signals from the antenna 1-1 and the RF unit 1-2 are demodulated by the demodulation unit 1-3 and input to the audio processing unit 1-5. The output of the audio processing unit 1-5 is input to the speaker 1-6. On the other hand, the audio signal from the microphone 1-7 is converted into a digital signal by the audio
-4 is input. The output of the modulation section 1-4 is the RF section 1-2.
And transmitted through the antenna 1-1. The channel quality estimator 1-8 receives the signal from the demodulator 1-3 and estimates the channel quality regarding the presence or absence of fading, noise, etc., their strength, and the like. In accordance with the estimated line quality, the voice quality improvement unit 1-9 improves the voice quality or the noise generator 1-1.
0 superimposes noise on speech. Also, according to the estimated line quality, the line quality status / usage status detector 1-1.
1 detects line quality and usage status, and the result is indicated by LED,
It is displayed on a display 1-12 such as an LCD.

In the embodiment of the present invention, a method for improving voice quality when line quality is deteriorated (details will be described later)
The communication area can be expanded by using. Specifically, as shown in FIGS. 2 and 3, when the line quality starts to deteriorate near the out of service area (YE in S1 of FIG. 2).
S) Further, it is checked whether the mobile phone is out of the service area (S2). If the mobile phone is out of the service area (YES in S2), only the noise is heard (S5), and the user is notified that the mobile phone is out of the service area. If it is not out of range (NO in S2), background noise is superimposed on the signal (S4).
On the other hand, if the line quality has not deteriorated (NO in S1), normal communication is performed (S3). In this way, the communication area is expanded, and the convenience for the user is improved.

Further, in the embodiment of the present invention, the FEC (Forwa) is added to the control data SA in order to use the audio data TCH of the data frame to be transmitted up to a high BER.
Error control is performed using rd Error Correction) so that the SA throughput is not reduced near the out-of-service area. That is, error control is performed on data, error correction is performed on control data SA, and only error detection is performed on audio data TCH. The details will be described later.

According to the embodiment of the present invention, with the above-described configuration, it is possible to increase the communication area by 16% and improve the convenience for the user.

Hereinafter, an indoor digital camera according to an embodiment of the present invention will be described.
Line quality estimation method for wireless voice communication system
Tools for voice quality improvement, error correction, and noise generation
Physical means and means for reporting line quality and usage
And will be described in detail.Line quality estimation method  Calls are allowed in digital wireless voice communication systems such as PHS
With the increase in active time, there is a demand for improved voice quality.
Improvement in voice quality, especially in a fading environment
Has become. In addition, indoor digital devices such as cordless phones
In a wireless radio communication system,
Improvement of voice quality under AWGN environment is also an issue. Conventionally, sound
Various studies to reduce voice quality degradation
Channel quality estimation techniques required for these voice quality improvement technologies.
Research is also being conducted. However, conventional line quality estimation
In the system, there is only estimation of burst errors such as fading
Is based on the estimation of only long-term deterioration outside the service area.
Was. The line quality estimation method according to the embodiment of the present invention
Channel quality estimation for both
It is something that is realized.

According to the embodiment of the present invention, a moving average of frame errors is used as a parameter for estimating channel quality. When measuring the moving average, the FER moving average of a long section for judging out of service and the FER moving average of a short section for judging short-term line quality deterioration such as fading and shadowing are independently used. This enables reliable line quality estimation.

FIG. 4 shows a channel quality estimating apparatus according to an embodiment of the present invention. An error detector a-1 detects a data error from the received data. Based on this output, the long section FER
The counter a-2 counts errors for a long section, and the short section FER counter a-3 counts errors for a short section. The judgment circuit a-5 compares these outputs with a threshold value a-4 to judge the line quality. According to this determination result,
The mute circuit a-6 is controlled.

For the long section FER counter a-2, the number CNT of frame error signals in the buffer is 0 <= C
When NT <= TH1, the judgment circuit a-5 has a low BER AWGN
Judge. On the other hand, when TH1 <CNT <= TH2, the determination circuit a-5 determines that the BER is high AWGN. Also, TH2 <CN
If T, the determination circuit a-5 determines that the area is out of the service area. However, the threshold value is 0 <TH1 <TH2.

Regarding the short section FER counter a-3,
When (the number of consecutive frame error signals)> (threshold (TH)), the determination circuit a-5 determines that fading has occurred.

With respect to the embodiment of the present invention, computer simulation was performed on short-term channel quality improvement, which is particularly important for improving voice quality, and click noise detection characteristics of the short-term channel quality estimation method were calculated. The simulation specifications are shown below. These are values normalized by the Doppler frequency Fd. Method: FSK-FDD Data rate (Fd · τ): 1.76E-04 Frame length (Fd · TF): 2.25E-02 Voice codec: 32 kbps ADPCM (CCITT G.721) Error patterns created by computer simulation The part of the added audio file where the amplitude fluctuation of the PCM signal is large was set as a click noise with a sense of incongruity. The non-false detection rate was defined as the following equation. Non-detection rate = (number of frames that were click noise but could not be determined as click noise) / (number of frames containing click noise) False detection rate = (number of frames that were incorrectly determined to be click noise) / (determined as click noise) FIG. 5 shows the characteristics of click noise and false detection rate in a fading environment. The point at which both the non-false detection rates are minimized is considered to be the optimum point for reducing the click noise. From FIG. 5, it can be seen that, when Fd · TF = 2.25e−2, the threshold of the number of consecutive frame errors is set to 3 or 4, so that the non-error detection rate can be minimized.

From the above, fading, shadow
For determining line quality degradation in a short period of time, such as
It can be seen that there is an optimum value for the number of consecutive frame errors. Fd
・ When TF = 2.25e-2, the threshold value of the number of consecutive error frames is set to 4.
Then, both the non-detection rate and the erroneous detection rate become minimum. This
As described above, experiments or measurement
Select the optimal number of frames by computer simulation
do it.Voice quality improvement method  Next, an apparatus / method for improving voice quality will be described.
I do.

In a digital wireless voice communication system, if a line error occurs due to fading, a weak electric field, or the like, voice quality is significantly degraded. In a system using a public network such as a PHS, the terminal only needs to improve the voice for fading as a countermeasure against a line error, and maintains a good voice quality systematically for a weak electric field by handover or the like. For this reason, voice quality has been conventionally improved for fading. On the other hand, in an indoor digital wireless voice communication system such as a cordless telephone, the terminal needs some kind of voice improvement means even in a weak electric field.

Therefore, according to the embodiment of the present invention,
Muting according to different wireless line quality situations,
The voice quality is improved by performing noise quality improvement processing such as adding noise, and the affinity for the user is improved.

In the conventional voice quality improvement method, the improvement process is performed by detecting an error such as CRC. However, although burst quality caused by fading has improved voice quality, random errors in a weak electric field have a problem that a large amount of voice frames are unnecessarily removed and voice quality is degraded. Therefore, using the method of independently estimating the short-term and long-term line quality as described above, the deterioration of the line quality due to fading, weak electric field, and the like is estimated, and the voice quality improvement method is performed according to the line condition. . For example, for a short time
As a speech improvement method according to the FER estimation result, no speech processing is performed when the number of continuous errors is small, and frame replacement is performed when the number of continuous errors is large. As a speech improvement method according to the long-term FER estimation result, speech processing is performed as the moving average amount increases from small to large. None, 1. 2. Add noise while leaving the original sound; Switch to adding noise without original sound.

When it is determined that the mobile phone is out of the service area, information such as out of the service area is transmitted to the user by adopting a PCM bit replacement and a background additional noise method as a fringe indicator in order to improve the affinity for the user.
This will be described later.

In order to confirm the communication quality when the proposed method is used, a subjective evaluation experiment (MOS (Mean Opinion Score))
(Evaluation, 5 steps of 1 to 5). The voice data in the environment shown below was created by computer simulation, and MOS evaluation was performed. Evaluation environment: Flat Rayleigh, AWGN Maximum Doppler frequency: 10 Hz Modulation / demodulation method: Asynchronous FSK Audio bit rate: 32 kbps Burst length: 80 bits (audio 72 bits, CRC 8 bits) FIG. 7 shows the result of the MOS evaluation in FIG. In both AWGN and fading environments, the method according to the embodiment of the present invention shows excellent characteristics. Comparing the average MOS values in all environments, the mute method is 1.87, no processing is 2.10, the method of the present invention is 2.36, and the proposed method is 0.3 compared to other methods.
It can be seen that MOS can be improved by about 0.5.

In the embodiment of the present invention, fading,
Line conditions such as a weak electric field are subject to short-term and long-term
Error, and muting,
Improve voice quality by combining no processing and adding noise.
According to the embodiment of the present invention, no processing or mu
The average MOS value is 0.3 to 0.5
Can be improved.Error correction method  In digital wireless voice communication systems, in addition to voice data,
The same applies to data for controlling wireless lines and user data.
Sometimes communicating. In such a case, control the wireless line.
Channels require higher line quality than voice channels.
It is. Especially when roaming like a cordless telephone.
Indoor digital wireless voice communication system
Control data must be transmitted reliably even in the vicinity
Absent.

FIG. 8 shows an example of a frame format. 1 is a preamble for the receiving circuit to perform bit synchronization with the received frame, 2 is a unique word for the bit-synchronized receiving circuit to further perform frame synchronization, 3 is control data, 4 is audio data, and 5 is error control. Is the parity that performs In the prior art, the control data 3 and the parity 5 are made the same to make an error-correctable code, or a code having a strong correction capability for the parity 5 is used.

When the voice data and the control data are the same or when strong coding is performed on the voice, the control data can be exchanged at the same time or early when the voice data cannot be communicated in the case of fringe or shadowing. It becomes impossible, and it becomes necessary to perform reconnection. In such a case, reconnection often takes time.

An optimal error control method at the layer 1 level for obtaining the channel quality of the control channel required for the channel quality of the voice channel will be described. Error control includes error detection-retransmission method, error detection-continuous transmission method,
There are a majority decision method and an error correction method. Among them, the retransmission method and the continuous transmission method require order control, and are not suitable for error control performed at the layer 1 level. Also, the majority voting method obviously lowers the effective transmission rate because it is necessary to send at least three pieces of the same information. Therefore, the error correction method is suitable at the layer 1 level.

By using a stronger error control code for the control data 3 shown in FIG. 8, the above-mentioned problem can be solved. In other words, the control data channel is effective even in a situation where voice data errors are large and conversation is difficult, so that it is possible to perform channel change / display of a fringe area without any problem. The control data 3 is further divided into an original control data portion 3a and an error correction parity 3b for control data as shown in the figure, and error correction is performed on the control data 3 independently.
Any error correction code may be used here, and for example, extended hamming (8, 4, 1) may be used. Since it is necessary to add a redundant code for error correction, the effective transmission rate is reduced. Therefore, error control may not be performed in a place where the radio wave environment is good, and the effective transmission rate may be increased.

The difference in the effective transmission rate with respect to the BER depending on the presence or absence of error correction was evaluated using computer simulation. The simulation conditions are as follows. The format of the assumed control channel is shown in FIG.
A BCH code that is easy to decode was used.

FIG. 10 shows the result under the AWGN environment, and FIG. 11 shows the result under the flat Rayleigh fading environment.
It can be seen from these figures that the characteristics change depending on the packet size. FIG. 12 shows the required BER for the packet size when the effective transmission rate is 0.9. In this figure, the characteristics of AWGN intersect when the packet size is 4 bytes. Therefore, it was found that better characteristics can be obtained by performing error correction on long packets. In particular, if the packet length is 5 bytes or more in an actual system, it is better to perform error correction.

According to this method, compared with the voice data,
Approximately 1 dB, since the reception sensitivity of the control data 3 is improved,
The above-mentioned problem can be solved.Specific measures for noise generation  A specific example of a device that generates background noise will be described. This
Is an example of adding a random number to only certain bits,
Is characterized in that 0 or 1 fixed data is added.
I do. FIG. 13A shows background noise in parallel data format.
Figure (b) shows an example of the device that generates the serial data format.
Shows an example of an apparatus for generating background noise. In FIG. 13 (a)
Here, the fixed data 11 is either “0” or “1”.
Data. k of the n-bit parallel data
A random occurrence of 0, 1 data in the
A number generator 10 is connected. bits other than the k-th bit
Is connected to fixed data 11. This device outputs
Noise is constant for data other than the k-th bit
Features a point.

The device shown in FIG. 13B includes a counter 20 for counting one code of PCM data, a timing for outputting a random number from the count value output by the counter, and a control circuit 21 for generating an output data selection signal. A random number generator 22 for generating a random number in accordance with a timing signal output from the control circuit, and a signal output from the random number generator and fixed data (0, 1) based on an output data selection signal output from the control circuit. Selector 2 for selecting and outputting
3 is provided. Random number data is inserted at the position of a specific bit of serial format data.

Input random numbers to all bits of PCM data
And the noise level is increased as shown in FIG.
This can cause discomfort to the listener. According to this embodiment
By adding random numbers to only certain bits,
A noise signal as shown in FIG. 14 (b) is obtained.
Noise can be heard without any discomfort.Line quality status / usage status notification means  Users can easily know the line quality status during use.
Easy to understand operation part of cordless telephone etc.
LED and LCD are provided in the part, lighting, blinking, color change etc.
It is configured to report the state of the line quality. Line quality
Is measured in a relatively short period of time as described above.
By doing so, it can be determined.

For example, as shown in FIG. 15, when the line quality is "good", the LED is lit in "blue", when it is "somewhat bad", the LED is lit in "yellow", and when it is "bad", "CH" is
"ANKey" lights up. And / or measure line quality over a relatively short period of time and consider possible factors as LC
Display on D. For example, a message such as "fading" is displayed on the LCD. If the measurement is performed over a long period of time and the situation is always bad, a message such as "This place has poor radio wave condition" may be displayed on the LCD to request a change in the location of the base unit. Alternatively, when the user moves from one place to another, a message “The situation has become better (or worse)” may be displayed to notify the user of the change in situation.

By making the status of the line visually easy to understand by means of LEDs, LCDs, etc., the user can easily check the status.

The above processing may be further advanced to display a method for improving the line quality. For example, FIG.
In, the channel quality improvement method estimating unit 1-13 stores the history of the status of the channel quality, examines the change, and outputs a method for improving the channel quality to the display 1-14 as a message. For example, when the reception level is gradually lowered and becomes affected by noise, a message “The radio wave is gradually weakening. Please return to the base station” is displayed. If the noise level is high, a message is displayed stating that "there is too much interference in the surrounding area, so move in a direction that does not interfere". Now move in another direction. " Alternatively, the past history may be examined, and a message “How many minutes ago the radio wave condition at the position was good, return to that position” may be displayed. When the effect of fading is large, a past message is examined and a similar message is displayed.

As described above, it is possible to inform the user of the timing of channel switching and the preferred place of use in an easy-to-understand manner.

In this specification, the means does not necessarily mean physical means, but also includes the case where the function of each means is realized by software. further,
The function of one unit may be realized by two or more physical units, or the function of two or more units may be realized by one physical unit.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a wireless mobile terminal device according to an embodiment of the present invention.

FIG. 2 is a schematic operation flowchart of the wireless mobile terminal device according to the embodiment of the present invention.

FIG. 3 is an operation explanatory diagram of the wireless mobile terminal device according to the embodiment of the present invention.

FIG. 4 shows a channel quality estimating device for a wireless mobile terminal device according to an embodiment of the present invention.

FIG. 5 is a graph illustrating click noise non-error detection rate characteristics in a fading environment of the channel quality estimating device of the wireless mobile terminal device according to the embodiment of the present invention.

FIG. 6 shows MOS evaluation results in an AWGN environment of the voice quality improvement device for a wireless mobile terminal device according to the embodiment of the present invention.

FIG. 7 shows a result of MOS evaluation in a fading environment of the voice quality improvement device of the wireless mobile terminal device according to the embodiment of the present invention.

FIG. 8 is an explanatory diagram of an error correction method of the wireless mobile terminal device according to the embodiment of the present invention.

FIG. 9 is an explanatory diagram of an error correction method of the wireless mobile terminal device according to the embodiment of the present invention.

FIG. 10 shows an effective transmission rate characteristic (AWGN) of an error correction method for a wireless mobile terminal device according to an embodiment of the present invention.
FIG.

FIG. 11 is a graph showing an effective transmission rate characteristic (fading) of the error correction method of the wireless mobile terminal device according to the embodiment of the present invention.

FIG. 12 shows the required BE for the packet size of the error correction method of the wireless mobile terminal device according to the embodiment of the present invention.
It is a graph which shows R.

FIG. 13 is a block diagram of a noise generation device of the wireless mobile terminal device according to the embodiment of the present invention.

FIG. 14 shows an example of noise by the noise generator of the wireless mobile terminal device according to the embodiment of the present invention (FIG. 14B) and an example of conventional noise (FIG. 14A).

FIG. 15 is an external view of a wireless mobile terminal device provided with channel quality status / use status notification means according to an embodiment of the present invention.

FIG. 16 is a schematic block diagram of a wireless mobile terminal device according to another embodiment of the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Narita 2-12-7 Hatchobori, Chuo-ku, Tokyo Uniteden Co., Ltd. (72) Inventor Omechu Wang 2-12-7 Hatchobori, Chuo-ku, Tokyo Uniden Co., Ltd. (72) Inventor Katsunori Yamamoto 2-chome, Hatchobori 2-chome, Chuo-ku, Tokyo Uniden Corporation (72) Inventor Takayoshi Kaneko 2-7-1, Hatchobori 2-chome, Chuo-ku, Tokyo Inside Uniden Corporation (72) Inventor Shoji Takamiya 2-12-7 Hatchobori, Chuo-ku, Tokyo Uniden Corporation (72) Inventor Tadayuki Hattori 2-7-17 Hatchobori, Chuo-ku, Tokyo Uniden Corporation (72) Inventor Eiji Shinmasa Chuo-ku, Tokyo Hatchobori 2-chome 12-7 Uniden Corporation F-term (reference) 5K014 AA01 BA00 EA04 FA09 GA02 HA00 HA05 5K067 AA22 AA23 BB02 CC04 DD45 DD 54 EE02 FF16 FF17 GG11 HH26

Claims (6)

[Claims] 1. A mobile radio terminal device for performing communication using a radio channel, a channel quality estimating unit for estimating a channel status by monitoring an error status of a received frame, and an estimation result by the channel quality estimating unit. A voice quality improvement unit that performs predetermined processing based on the voice quality and improves the voice quality, and when it is determined that the communication quality is out of the communication range by the line quality estimation unit, the voice quality improvement unit controls so as to output only noise, The mobile radio terminal device, wherein when the line quality estimating unit determines that the signal is out of the communication area, the voice quality improving unit performs control so that background noise is superimposed on the signal and output. 2. An error detector for detecting an error in received data, a long section error counter for counting errors in a predetermined long section based on an output of the error detector, A short section error counter for counting errors for a predetermined short section based on the output of the device, and comparing the output of the long section error counter and / or the output of the short section error counter with a predetermined threshold value to thereby determine the line quality. The mobile radio terminal device according to claim 1, further comprising a determination circuit for estimating the mobile radio terminal device. 3. The short interval error counter calculates a moving average of errors in a short interval to determine short-term line quality degradation including fading and shadowing, and the long interval error counter is out of range. 3. The mobile radio terminal device according to claim 2, wherein a moving average of an error is obtained in a long section to determine the fact. 4. A channel quality status detecting unit for detecting a status of a channel quality based on an estimation result by the channel quality estimating unit;
The mobile radio terminal device according to claim 1, further comprising: a display unit that displays a channel quality based on the channel quality status detection unit. 5. A channel quality improvement method estimator for estimating a channel quality improvement method based on an estimation result by the channel quality estimator, and a display unit for displaying a channel quality improvement method based on the channel quality improvement method estimator. The mobile radio terminal device according to claim 1, comprising: 6. In a mobile radio terminal device that performs communication using a radio channel, when transmitting a frame including a preamble, a unique word, control data, voice data, and an error control code, an error corresponding to only the control data is transmitted. A mobile wireless terminal device comprising: an error control unit that generates a control code, adds the control code to the control data, and transmits the control data.