JPH10145261A - Mobile radio terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile radio terminal device, which has a means that generates background noise which does not give a listener a feeling that something is wrong, without generating different noise even in a state in which burst errors occur, so that special data which specially includes coded data for background noise generation may be lost in a mobile radio terminal device which adopts a VOX (voice-operated communication) system. SOLUTION: This device is provided with a data buffer 2, a deciding means 3 that decides whether a special pattern has a transmission error or not and a controlling means 4, which successively stores background noise generative coded data in the buffer 2 and gives it to a background noise generating means 1. While the means 3 decides that no transmission error exists, and on the other hand temporally and randomly selects and fetches background noise generating coded data from the buffer 2 and gives it to the means 1, when the means 3 continuously decides that transmission errors exist.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a VOX (Voice Op
More particularly, the present invention relates to a background noise generation method for generating a reproduced signal corresponding to background noise when there is no sound in a receiving side device.

[0002]

2. Description of the Related Art The VOX system is a system for saving power of a mobile radio terminal on the transmitting side by operating a speech encoder when there is a speech signal and not operating it in a silent section where there is no speech signal. is there. Hereinafter, an outline of the background noise generation method in the conventional VOX method will be described with reference to FIG.

FIG. 22 is a configuration diagram of a conventional mobile radio terminal. As shown in FIG. 22 (a), the transmitting device
A / D converter 30, speech detector 31, speech encoder 3
2, pre-pattern generator 33, post-pattern generator 3
4. It has a switch 35 and the like.

[0004] A / D converter 30 receives an audio signal. The output of the A / D converter 30 is connected to a speech detector 31 and a speech encoder 32. The output of the speech detector 31 is connected to a speech encoder 32, a pre-pattern generator 33, a post-pattern generator 34, and a switch 35. Outputs of the pre-pattern generator 33 and the post-pattern generator 34 are connected to a switch 35. The output (line data) of the switch 35 is sent to the wireless transmission path.

An outline of the operation of the transmitting apparatus having the above configuration will be described. The input audio signal is converted into a digital signal having a predetermined bit width by an A / D converter 30 and input to an audio detector 31 and an audio encoder 32. The voice detector 31 detects whether the telephone is talking (voiced) or paused (silent) based on the magnitude comparison between the output value of the A / D converter 30 and the threshold, and compares the detection result with the voice encoder 32. Pattern generator 33
And a post pattern generator 34 and a switch 35.

[0006] When the detection result of the speech detector 31 is a sound, the speech encoder 32 encodes the speech information digitized by the A / D converter 30 by a predetermined encoding method and outputs the speech code. The converted data is output to the switch 35. Further, the speech encoder 32 operates for a predetermined time when the detection result of the speech detector 31 changes from voiced to silence, outputs encoded data for background noise generation to the switch 35, and then the silence state is changed. During the continuation, it operates for a predetermined time at a constant time interval and outputs the encoded data for background noise generation to the switch 35.

The pre-pattern generator 33 includes the voice detector 3
When the detection result of No. 1 changes from silence to speech, it operates for a predetermined time and changes from silence to speech, that is, switches a specific pattern (hereinafter, referred to as “pre-pattern”) indicating that a speech head has been detected. Output to the container 35. The post pattern generator 34 operates for a predetermined period of time when the detection result of the voice detector 31 changes from voice to silence to change from voice to silence, that is, a specific signal indicating that the tail has been detected. The pattern (hereinafter referred to as “post pattern”)
After that, while the silent state continues, the post-pattern is operated for a predetermined time at a predetermined time interval to switch the post pattern.
Output to

When the detection result of the voice detector 31 changes from silence to speech, the switch 35 outputs the output (pre-pattern) of the pre-pattern generator 33 and the output of the voice coder 32 (voice coded data). ). Then, the switch 35
Selects the output (speech coded data) of the speech coder 32 while the detection result of the speech detector 31 indicates a sound state.

As a result, the switch 35 outputs the pre-pattern and the voice-encoded data as line data immediately after switching from silence to speech, and then continuously outputs the voice-encoded data as line data. I do. On the other hand, when the detection result of the voice detector 31 changes from voiced to silence, the switch 35 outputs the output (post pattern) of the post pattern generator 34 and the voice coder 3 in the silent period.
2 is selected (encoded data for background noise generation).

[0010] As a result, the switch 35 outputs the post pattern and the accompanying speech coded data for background noise generation as line data at a constant repetition cycle. Therefore, as described in the claims, it can be said that the speech coded data for background noise generation is a part of the post pattern. Next, as shown in FIG. 22 (b), the receiving side device includes a pre / post pattern detector 40, a switch 41, a speech decoder 42, a background noise generator 43, a switch 44, D
/ A converter 45 and the like.

Line data is input to the pre / post pattern detector 40. Pre / post pattern detector 40
Are connected to switches 41 and 44. Switch 41
Is connected to a speech decoder 42 and a background noise generator 43. Outputs of the audio decoder 42 and the background noise generator 43 are connected to a switch 44, respectively. Switch 4
4 is connected to a D / A converter 45.

An outline of the operation of the receiving apparatus having the above configuration will be described. When the pre / post pattern detector 40 detects the pre-pattern from the line data input from the wireless transmission line, the switch 41 performs the voice decoding on the line-coded voice data until the post-pattern is detected. The switch 42 is caused to perform the switching operation, and the switch 44 is caused to select the output of the audio decoder 42.

As a result, the digital audio information decoded by the audio decoder 42 is transmitted from the switch 44 to the D / A converter 4.
5 and is converted into an analog audio signal and output to a listener. On the other hand, the pre / post pattern detector 4
A value of 0 causes the switch 41 to perform a switching operation of providing the post-pattern which is line data and the coded data for generating background noise accompanying the post-pattern to the background noise generator 43 every time a post pattern is detected from input line data. At the same time, the switch 44 selects the output of the background noise generator 43.

As a result, the background noise generator 43 generates a reproduced digital signal corresponding to the background noise based on the background noise generation coded data inputted immediately after the silence, and thereafter performs post-processing at a constant repetition period. A reproduced digital signal corresponding to the background noise is generated based on the background noise generation coded data input along with the pattern. This reproduced digital signal is input to a D / A converter 45 via a switch 44, where it is converted into a reproduced signal corresponding to analog background noise and output to a listener.

As described above, in the VOX system, the speech coder or the like is operated intermittently in a silent section for the purpose of power saving of the mobile radio terminal on the transmitting side, but the mobile station on the receiving side moves in the silent section in the silent section. The wireless terminal device can output a reproduced sound equivalent to background noise, so that a listener does not feel uncomfortable in a silent section.

[0016]

[0006] Here, in the wireless transmission path, unlike the wired transmission path, transmission errors may occur in the line data due to various factors. If a transmission error occurs in a silent section, an unusual sound different from the background noise will be heard at the ear, which causes a sense of incongruity to the listener.

If the transmission error occurs sporadically, the degree of discomfort given to the listener is low, so the problem can be said to be relatively small. However, when the transmission error is a continuous burst error, the human ear can clearly perceive even abnormal noise of several milliseconds to several tens of milliseconds, which causes an unpleasant abnormal noise and a considerable discomfort. Become. This burst error is likely to occur, for example, in a place surrounded by a high-rise building, in a tunnel, or in a place where radio waves are difficult to pass.

Therefore, as a countermeasure against this burst error, when the post pattern and the encoded data for background noise generation can be correctly received, they are stored, and the post pattern and the encoded data for background noise generation can be correctly received. When the data is lost, it is conceivable to generate background noise using the encoded data for generating background noise immediately before the data is lost.

However, the duration of the burst error is long,
Depending on the frequency characteristics of the background noise generation coded data, if the same background noise generation coded data is used repeatedly when the state in which the post pattern and the background noise generation coded data cannot be correctly received continues. Since a periodic sound may be generated, which also gives a sense of incongruity to the listener, simply storing the encoded data for background noise generation is not sufficient.

The present invention has been made in order to solve such a problem, and can be applied to a case where a burst error occurs in which a specific pattern including encoded data for generating background noise is lost. It is an object of the present invention to provide a mobile wireless terminal device having means capable of generating background noise that does not generate sound and does not give a listener an uncomfortable feeling.

[0021]

FIG. 1 is a block diagram showing the principle of the first aspect of the present invention. The invention according to claim 1 is a background noise generating means for receiving a specific pattern indicating a silent section input from a transmission path, and generating a reproduced signal corresponding to the background noise based on the encoded data for generating background noise included in the specific pattern. 1. In the mobile radio terminal device provided with No. 1, the data buffer 2, the judging means 3 for judging whether or not there is a transmission error in the characteristic pattern, and the background noise generation code while the judging means 3 judges that there is no transmission error. The coded data for background noise generation is sequentially stored in the data buffer 2 and supplied to the background noise generation means 1 while the determination means 3 continuously determines that there is a transmission error. Is selected at random in time and taken out,
And a control means 4 for providing the control signal to the background noise generating means 1.

FIG. 2 is a block diagram showing the principle of the present invention. The invention described in claim 2 is the first invention.
In the mobile wireless terminal device described in the above, when the determination means 3 continuously determines that there is a transmission error, the difference between the frame power of the reproduction signal generated by the background noise generation means 1 and the frame power of the reproduction signal generated this time is calculated. Power adjusting means 5 for obtaining a reproduced signal whose frame power has been adjusted based on the obtained signal.
It is characterized by having.

According to a third aspect of the present invention, in the mobile radio terminal device according to the first aspect, when the determining means 3 continuously determines that there is a transmission error, the background noise generating means 1 A power adjusting means for obtaining a difference between the frame power sample average value of the reproduced signal thus obtained and the frame power sample average value of the reproduced signal generated this time, and outputting a reproduced signal having an average power adjusted based on the difference. I do.

FIG. 3 is a block diagram showing the principle of the present invention. According to a fourth aspect of the present invention, there is provided a background noise generation apparatus which receives a specific pattern indicating a silent section input from a transmission path, and generates and outputs a reproduction signal corresponding to the background noise based on the encoded data for background noise generation included therein. In the mobile radio terminal device including the means 1, the data buffer 2, the white noise generating means 6 for generating white noise, and the determining means 3 for determining whether or not there is a transmission error in the characteristic pattern.
While the determination means 3 determines that there is no transmission error, the first control means 4a which sequentially stores the encoded data for background noise generation in the data buffer and supplies it to the background noise generation means, and the determination means 3 When it is determined that there is a transmission error continuously, if the number of determinations does not exceed the number of data stored in the data buffer 2, the data buffer 2
, The coded data for background noise generation is selected at random in time and given to the background noise generation means 1 while the number of times that it is determined that there is a transmission error is determined by the data buffer 2.
And a second control unit 4b that supplies the output of the white noise generation unit 6 to the background noise generation unit 1 as encoded data for background noise generation when the number of data stored in the white noise generation unit 6 exceeds the number of data stored.

According to a fifth aspect of the present invention, in the mobile radio terminal device according to the fourth aspect, the frame power of the reproduction signal generated by the background noise generation means 1 using the immediately preceding encoded data for background noise generation and the subsequent frame power It is characterized by comprising a power adjusting means 5 for obtaining a difference between a frame signal of a reproduced signal generated by white noise and the frame power and outputting a reproduced signal whose frame power is adjusted based on the difference.

According to a sixth aspect of the present invention, in the mobile radio terminal of the fourth aspect, the average value of the frame power samples of the reproduced signal generated by the background noise generating means 1 using the immediately preceding encoded data for background noise generation. And a power adjusting means 5 for calculating a difference between the average value and a frame power sample value of a reproduced signal generated by white noise and outputting a reproduced signal whose average power is adjusted based on the difference.

FIG. 4 is a block diagram showing the principle of the present invention. The invention according to claim 7 is the invention according to claim 4.
In the mobile radio terminal device described in 1 above, a reproduced signal obtained by multiplying a reproduced signal generated by the immediately preceding encoded data for background noise generation by the background noise generating means 1 and a reproduced signal generated by the subsequent white noise by a variable gain is added. Is provided.

According to an eighth aspect of the present invention, in the mobile radio terminal device according to the fourth aspect, when the judgment means 3 changes the judgment from the presence of a transmission error to the absence of a transmission error, the background noise generation means 1 outputs the immediately preceding white noise. Variable gain adding means 7 is provided which outputs a reproduced signal obtained by multiplying a reproduced signal generated by noise and a reproduced signal generated by the encoded data for background noise generation by a variable gain and outputting the resultant signal.

According to a ninth aspect of the present invention, in the mobile radio terminal device according to any one of the first to seventh aspects, when the determination means changes the determination from the presence of a transmission error to the absence of a transmission error. Power adjusting means for obtaining a difference between the frame power of the reproduced signal generated immediately before the change by the background noise generating means and the frame power of the reproduced signal generated after the change, and outputting a reproduced signal whose average power is adjusted based on the difference. And

Next, the operation of the present invention will be described. According to the first aspect of the present invention, in the silent section,
While the determination means 3 determines that there is no transmission error, the control means 4 sequentially stores the encoded data for background noise generation in the data buffer 2 and supplies it to the background noise generation means 1. As a result, a reproduced sound of background noise that does not give the listener a sense of discomfort is produced.

Thereafter, the judging means 3 judges that there is a transmission error, and if the transmission error continues, the control means 4 randomly selects the coded data for background noise generation from the data buffer 2 and extracts it. , The background noise generating means 1
Give to. As a result, the reproduced background noise does not generate a periodic sound that depends on the frequency characteristics of the encoded data for background noise generation. A playback sound is obtained.

According to the second aspect of the present invention, when the determination means 3 continuously determines that there is a transmission error, the background noise generation means 1 compares the frame power of the reproduction signal generated last time with the reproduction signal generated this time. And the power adjusting means 5 outputs a reproduced signal in which the frame power is adjusted based on the difference. As a result, it is possible to smoothly switch the selected encoded data for background noise generation,
You can keep the listener from feeling uncomfortable.

According to the third aspect of the present invention, when the determining means 3 continuously determines that there is a transmission error, the background noise generating means 1 calculates the average value of the frame power sample of the reproduction signal generated last time and the current generation. The difference between the average value of the reproduced signal and the average value of the frame power samples is obtained, and the power adjusting means 5 outputs the reproduced signal whose average power is adjusted based on the difference. As a result, it is possible to smoothly switch the selected encoded data for background noise generation, so that it is possible to prevent the listener from feeling uncomfortable.

According to the fourth aspect of the present invention, during the silent period, the first control means 4a sequentially stores the encoded data for background noise generation in the data buffer while the judgment means 3 judges that there is no transmission error. And gives it to the background noise generating means. As a result, a reproduced sound of background noise that does not give a strange feeling to the listener can be obtained. Thereafter, the judging means 3 judges that there is a transmission error, and if the number of judgments by the judging means 3 does not exceed the number of data stored in the data buffer 2 when the transmission error continues, the second control means 4b 2, coded data for background noise generation is selected at random in time and taken out.
Give to.

As a result, it is possible to prevent the generation of periodic sounds in the same manner as in the first aspect of the present invention, and to obtain a reproduced sound of background noise which does not give a listener a sense of incongruity. On the other hand, when the number of times of judgment by the judging means 3 exceeds the number of data stored in the data buffer 2, the second control means 4b uses the output of the white noise generating means 6 as background noise generating coded data and outputs the background noise generating means 1. Give to.

When the number of transmission error occurrences is larger than the number of stored data, in the first aspect of the present invention, there is a possibility that a periodic sound is generated, but this can be prevented. According to the fifth aspect of the present invention, the difference between the frame power of the reproduction signal generated by the immediately preceding background noise generation encoded data and the frame power of the reproduction signal generated by the subsequent white noise is calculated by the background noise generation means 1. The power adjustment means 5 outputs a reproduced signal whose frame power has been adjusted based on the signal.

As a result, the sound source can be switched smoothly, so that the listener can be prevented from feeling uncomfortable. According to the sixth aspect of the present invention, the average value of the frame power sample of the reproduced signal generated by the background noise generation means 1 using the immediately preceding encoded data for generating the background noise and the average of the frame power sample of the reproduced signal generated by the white noise thereafter. Find the difference with the value,
Based on this, the power adjusting means 5 outputs a reproduced signal whose average power has been adjusted.

As a result, the sound source can be switched smoothly, so that the listener can be prevented from feeling uncomfortable. According to the seventh aspect of the present invention, the variable gain adding means 7 combines the reproduced signal generated by the background noise generating means 1 with the immediately preceding encoded data for background noise and the reproduced signal generated by the white noise. And outputs a reproduction signal obtained by multiplying by.

As a result, the sound source can be switched smoothly, so that the listener can be prevented from feeling uncomfortable. According to the eighth aspect of the present invention, when the judgment means 3 changes the judgment from the presence of transmission error to the absence of transmission error, the reproduction signal generated by the background noise generation means 1 using the immediately preceding white noise and the subsequent encoding for background noise generation The reproduction signal generated by the data is multiplied by the variable gain by the variable gain addition means 7 and the reproduction signal is output.

As a result, the sound source can be switched smoothly, so that the listener can be prevented from feeling uncomfortable. According to the ninth aspect of the present invention, in the mobile wireless terminal device according to any one of the first to seventh aspects, when the determination means changes the determination from the presence of a transmission error to the absence of a transmission error, the background noise may be reduced. The generator calculates the difference between the frame power of the reproduced signal generated just before the change and the frame power of the reproduced signal generated after the change, and based on the difference, outputs the reproduced signal whose frame power is adjusted.

As a result, it is possible to smoothly switch the data and the sound source for generating the background noise, and it is possible to prevent the listener from feeling uncomfortable.

[0042]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 is a configuration diagram of the mobile radio terminal device according to the embodiment of the present invention. Conventional example (FIG. 22B)
The same components as those described above are denoted by the same reference numerals and names. FIG.
As shown in the figure, the mobile radio terminal device on the receiving side of the present embodiment is provided with a background noise generation controller 10 instead of the background noise generator 43 shown in FIG. The background noise generation controller 10 is configured as shown in FIG. 6, FIG. 9, FIG. 11, FIG. 14, FIG. 16, and FIG. 19 in order to variously control the generation mode of the background noise generated in a silent section. Hereinafter, the configuration and operation of the background noise generation controller 10 will be described in this order.

FIG. 6 is a block diagram of an embodiment corresponding to claim 1 (a block diagram of a background noise generation controller of the first embodiment). The background noise generation controller of the first embodiment includes:
An error counter 11, a buffer counter 12, a pre / post pattern receiver 13, a central control unit 14, an encoded data buffer 15, and a background noise generator 16 are provided. The pre-post pattern receiver 13 receives a pre-pattern included in the line data input from the switch 41, a post pattern and coded data for generating background noise accompanying the post pattern. They are provided to a central control unit 14.

The present embodiment is concerned with the operation of reproducing a signal corresponding to background noise in a silent section. Therefore, in the following description, there is no description about the pre-pattern. The central control unit 14 includes a central processing unit (hereinafter, referred to as a “CPU”), a program memory, and a working memory, and further includes an error counter 11, a buffer counter 12, and an encoded data buffer 15 under its control.

When a received signal of a post-pattern and encoded data for generating background noise is input from the pre / post-pattern receiver 13, the central control unit 14 determines whether there is a transmission error. When there is a transmission error, the error counter 11 is set, and thereafter, when the transmission error is recovered, the error counter 11 is reset. When there is no transmission error in the input post pattern and the background noise generation encoded data, the central control unit 14 sequentially stores the background noise generation encoded data in the encoded data buffer 15. The storage amount is counted by the buffer counter 12. The data buffer 15 has a capacity capable of storing a predetermined number of encoded data for background noise generation.

Then, the central control unit 14 extracts the coded data for generating background noise from the coded data buffer 15 and supplies it to the background noise generator 16. Background noise generator 16
Is equivalent to the conventional background noise generator 43,
In the present embodiment, under the control of the central control unit 14, the background noise reproduced at the time of normal reception and at the time of continuous error is output to the switch 44.

In the above configuration, the correspondence with claim 1 is as follows. The background noise generator 16 corresponds to the background noise generator 1. Data buffer 2
Corresponds to the coded data buffer 15. The central control unit 14 corresponds to the determination unit 3 and the control unit 4. Next, FIGS. 7 and 8 are operation flowcharts according to the first embodiment. FIG. 7 relates to a case where a post pattern or the like is normally received, and FIG. 8 relates to a case where a post pattern or the like is not normally received. Hereinafter, the operation of the background noise generation controller according to the first embodiment will be described with reference to FIGS.

In FIG. 7 and FIG. 8, "POST"
Means post pattern. “CODE” means encoded data for background noise generation. “ERR CNT” means the error counter 11. “BUF CNT” means the buffer counter 12. The same applies to the following embodiments. In FIG. 7, in S1, it is determined whether or not the post-pattern and the encoded data for background noise generation input from the pre / post-pattern receiver 13 have been normally received without transmission errors.

The case where the transmission cannot be normally received due to the transmission error includes the case where the next post pattern cannot be received even if a predetermined time has elapsed after the reception of the previous post pattern.
The post pattern may be received, but there may be a transmission error in the encoded data for background noise generation accompanying the post pattern.
If the post pattern cannot be received, the coded data for background noise generation accompanying the post pattern cannot be received. If there is an error in the encoded data for background noise generation,
Since the data is not available for background noise generation, the data is equivalent to lost.

Therefore, in this embodiment, the case where there is no error is referred to as “no transmission error”, and the case where there is any error is referred to as “transmission error”. In the post pattern detection, it is also determined whether post patterns match or not. In error detection, CRC (Cyclic Redundancy Check) is generally used. The CRC is a check bit added to detect a case where an error in a propagation path cannot be corrected by the error correction processing of the decoder. Often used to protect

After performing error correction processing, the decoder can check this CRC bit to detect whether an error has occurred in the data protected by the CRC. When an error occurs, CRC = 1, and when no error occurs, CRC = 0.

When there is no transmission error and normal reception is possible,
The determination in S1 is affirmative (YES), and the process proceeds to S2. On the other hand, if the transmission was not successful due to a transmission error, S
The determination of 1 is negative (NO), and the process proceeds to S10 of FIG.
S10 will be described later. In S2, it is determined whether or not the count value of the error counter 11 is 0. The count value of the error counter 11 indicates the previous reception state. Subsequent processing differs depending on whether or not a transmission error has occurred during the previous reception.

In S2, if the count value of the error counter 11 is 0, the determination is affirmative (YES), and the buffer counter 12 is incremented by one (S3).
It is determined whether the value of the buffer counter 12 has exceeded a prescribed value N (S4). In S4, the buffer counter 1
If the value of 2 does not exceed the specified value N, the determination is negative (NO), the coded data for background noise generation received this time is stored in the coded data buffer 15 (S8), and the coded data for background noise generation is generated. To the device 16 for driving (S9), S1
And prepare for the next reception.

In S4, the buffer counter 1
If the value of 2 exceeds the specified value N, the determination is affirmative (Y
ES), the stepping operation of the buffer counter 12 is stopped in S5, the process proceeds to S8, and the coded data for background noise generation received this time is stored in the coded data buffer 15, and S9 is performed.
And returns to S1 to prepare for the next reception. That is, the encoded data buffer 15 can hold up to N (N ≧ 2) encoded data for background noise generation. When the stored encoded data for background noise generation exceeds the prescribed value N, the past data is discarded temporally, and the latest N pieces of encoded data for background noise generation are always held. The specified value N is determined empirically from actual operation, for example.

On the other hand, in S2, the error counter 11
Is not 0, the determination is negative (NO). In this case, it is indicated that the current reception is the first one that has been successfully received.

Therefore, in this case, the error counter 11
Then, the buffer counter 12 is cleared (S6), and the buffer counter 12 is incremented by one (S7) to S8
Then, the coded data for background noise generation received this time is stored in the coded data buffer 15, and the operation of storing the coded data for background noise generation is restarted. Thereafter, the process returns to S1 via S9 to prepare for the next reception.

If the encoded data for background noise generation can be correctly received, the background noise generator 16 reproduces and outputs a signal equivalent to background noise equivalent to that of the related art. Here, the encoded data for the background noise generation is sequentially stored in the encoded data buffer 15 when the data has been continuously and correctly received. If a stable propagation state in which no transmission error occurs continues for at least a predetermined period, the encoded data buffer 15
A considerable amount of encoded data for background noise generation is held.

These data are used when transmission errors continue. That is, if a transmission error occurs while the silent section continues, the process proceeds from S1 to S10, and it is determined whether or not the value of the error counter 11 is 0. That is, it is determined whether or not the current transmission error is the first time. In S10, if the value of the error counter 11 is 0, the determination is affirmative (YES), and S11 to S11
After the processing of the first transmission error of 14, the process returns to S1.

That is, the error counter 11 is incremented by one (S
11) At the same time, the stepping operation of the buffer counter 12 is stopped (S12) and the storing operation to the coded data buffer 15 is stopped (S13), the background noise generator 16 is driven (S14), and the process returns to S1. . At this time, the background noise generator 16 obtains the latest encoded data for background noise generation from the encoded data buffer 15 and reproduces a sound equivalent to the background noise (S14).

If the transmission errors continue, the value of the error counter 11 is not 0, so the determination in S10 is negative (N
O), and the error counter 11 is incremented (S15).
After the processing of S16, the process returns to S1. In S16, encoded data for background noise generation is randomly selected from the encoded data buffer 15 and output to the background noise generator 16 to reproduce a signal equivalent to the background noise.

Thus, even if the state in which the encoded data for background noise generation cannot be received continues, the same encoded data for background noise generation is not continuously used repeatedly, so that the background noise without periodic sound is equivalent. Is obtained. Next, FIG. 9 is a configuration diagram of an embodiment corresponding to claims 2 and 3 (a configuration diagram of a background noise generation controller of a second embodiment). In the second embodiment, the first embodiment (FIG. 6)
, A previous frame power buffer 17 and an output power regulator 18 are provided.

In FIG. 9, the output of the background noise generator 16 is composed of a previous frame power buffer 17 and an output power controller 18.
And connected to. The output of the previous frame power buffer 17 is connected to an output power regulator 18. In the second embodiment, the output of the background noise generator 16 is output to the direct switch 44 at the time of normal reception, and is output to the previous frame power buffer 17 and the output power adjuster 18 at the time of a continuous error.
The background noise at the time of the continuous error is output from the output power controller 18 to the switch 44. These controls are performed by the central control unit 14.

In the above configuration, the entirety of the previous frame power buffer 17 and the output power regulator 18 or the output power regulator 18 corresponds to the power regulator 5 according to the second and third aspects. Next, FIG. 10 is an operation flowchart according to the second embodiment. In the second embodiment, the operation is the same as that of the first embodiment (FIG. 7) in a situation without a transmission error in which the determination in S1 of FIG. 7 is affirmative (YES), and the background noise in FIG. Generator 16
Outputs the reproduced background noise directly to the switch 44.

FIG. 10 shows that the determination in S1 of FIG. 7 is negative (N
8) shows the operation of the second embodiment under the situation where there is a transmission error of O), and the processing (S10 to S16) of FIG.
This is an operation in which the process of S20 is added. Hereinafter, the operation of the background noise generation controller according to the second embodiment will be described with reference to FIG. In FIG. 10, in a situation where there is a transmission error in which the determination in S1 of FIG. 7 is negative (NO), after the processing in S14 or S16, the magnitude relationship between the frame power of the previous frame and the frame power of the current generation frame is determined. A comparison is made (S17).

If there is a difference, the determination in S18 is affirmative (YES), the generated reproduction signal is power-adjusted and output (S19), and the process returns to S1. If the power difference between the previous frame and the current frame is large, the listener is conscious of the switching of the frames, which causes the listener to feel uncomfortable. It can be prevented. Therefore, if there is no difference in S18, the determination is negative (NO), the generated reproduction signal is output without power adjustment (S20), and the process returns to S1.

Here, the same effect can be obtained by using a sampled average value of the frame power instead of the frame power itself, instead of the frame power itself. These may be sent from the transmitting side. However, in the second embodiment, for example, the following is realized on the receiving side. The background noise generator 16 supplies the previously reproduced background noise to the previous frame power buffer 17 and supplies the currently reproduced background noise to the output power controller 18.

The previous frame power buffer 17 calculates the power of the input immediately preceding frame and holds the calculated power. Alternatively, the previous frame power buffer 17 calculates the sampled average power of the input immediately preceding frame power and holds it. The output power controller 18 calculates the input power of the current frame and calculates the difference between the input power and the power of the immediately preceding frame acquired from the previous frame power buffer 17 (claim 2). Or, the output power controller 18
Calculates the input sample average power of the current frame and calculates the difference between the input average power and the sample average power of the immediately preceding frame acquired from the previous frame power buffer 17 (claim 3). Then, when there is a difference between the predetermined values, smooth power adjustment is performed (claims 2 and 3).

The above processing can be explained as follows. First, it is assumed that a relationship represented by Expression (1) is established between the transmission interval T [second] of the post-pattern and the encoded data for background noise generation on the transmission side and the frame length t [second]. In addition,
In the equation (1), n is a positive number. T = nt (1) Expression (1) indicates that n frames exist in T seconds of the transmission interval of the encoded data for background noise generation.

Also, assuming that the post pattern and the encoded data for background noise generation have been lost and that a certain time k has elapsed since the start of using the data stored in the encoded data buffer 15, the data selected at the certain time k is assumed. frame power P _(k) is the background noise generated coded data for C _(k) by the reproduction signal _{Cn (k), P (k} ) = Σ (Cn (k) (i) 2) ····· (2 ). Note that the product sum is from i = 1 to n.

The current frame power P _(k) according to equation (2 ₎
Is compared with the frame power P _(k-1) of the immediately preceding reproduced signal stored in the previous frame power buffer 17 (S1).
7). Then, when the difference is taken to be 0, the reproduced signal is output as it is without performing power adjustment (S18 → S2).
0). On the other hand, if a difference between the predetermined values is found by taking the difference,
Reproduction signal Cn based on encoded data C _(k) for background noise generation
_The following equation (3) is applied to _(k) to obtain a power-adjusted reproduced signal Vn _(k) (S18 → S19).

Vn _(k) = (P _(k) / P _(k−1) ) × Cn _(k) + Cn _(k) × ｛(P _(k) −P _(k−1) ) / n｝ X (3) where X is the number of frames and X = 1, 2,.
, N.

This makes it possible to smoothly adjust the power level of the reproduced background noise signal during the transmission interval T seconds of the post pattern. Also, the power of the reproduced signal can be adjusted not by the difference in frame power but by the average sample power. That is, the previous frame power buffer 17 stores the immediately preceding frame power sample average value PS _(k-1) instead of the immediately preceding frame power P _(k-1) . The frame power sample average value PS _(k) at a certain time k is as follows: PS _(k) = {(Cn _(k) (i) ² )} / n (4) Note that the product sum is from i = 1 to n. Here, n is the number of samples in one frame.

The reproduced signal Vn _(k) (i) whose power has been adjusted with the sample average power can be obtained by equation (5). Vn _(k) (i) = (PS _(k) / PS _(k-1) ) × Cn _(k) (i) + Cn _(k) (i) × ｛(PS _(k) −PS _(k−1) ) / N｝ X (5) where X = 1, 2,..., N.

This makes it possible to smoothly adjust the power level of the reproduced background noise signal during the transmission interval T seconds of the post pattern. Next, FIG. 11 is a configuration diagram of the embodiment corresponding to claim 4 (configuration diagram of the background noise generation controller of the third embodiment). In the third embodiment, in the first embodiment (FIG. 6), a white noise generator 19 is juxtaposed to the encoded data buffer 15 and connected to the central control unit 14.

In the third embodiment, the coded data for background noise generation is stored in the coded data buffer 15 in the same manner as in the first embodiment when there is no transmission error. Then, in a situation where there is a transmission error, the coded data for background noise generation stored in the coded data buffer 15 and the white noise generator 19 generate the data for reproducing the background noise under certain conditions. Switch to white noise. The above control operation is performed by the central control unit 14.

In the above configuration, the correspondence with claim 4 is as follows. The background noise generator 16 corresponds to the background noise generator 1. Data buffer 2
Corresponds to the coded data buffer 15. The central control unit 14 corresponds to the determination unit 3, the first control unit 4a, and the second control unit 4b. The white noise generator 19 corresponds to the white noise generator 6.

FIG. 12 and FIG. 13 are operation flowcharts according to the fourth embodiment. FIG. 12 shows a case where a post pattern or the like is normally received.
Relates to a case where a post pattern or the like cannot be normally received. The operation when the post pattern or the like can be normally received is not different from the operation of the first embodiment (FIG. 7), and the operation when the post pattern or the like cannot be normally received is mostly the first operation. This is the same as the operation of the embodiment (FIG. 8).

In FIGS. 12 and 13, it is clearly shown that the processes in parentheses are the same as those shown in FIGS. 7 and 8. The same applies to the following embodiments. Hereinafter, the operation of the background noise generation controller according to the third embodiment will be described with reference to FIGS. The description of the processes in which parentheses are added to the reference numerals will be omitted, and the description will be focused on the portion (FIG. 13) according to the third embodiment.

In a situation where there is no transmission error in which the determination in (S1) of FIG. 12 is affirmative (YES), the operation of the third embodiment is the same as the operation of the first embodiment (FIG. 7). is there. That is, in FIG. 11, the background noise generator 16 outputs the reproduced background noise directly to the switch 44. On the other hand, in FIG.
In a situation where there is a transmission error for which the determination in (S1) is negative (NO), the processing ((S10) to (S14)) for the first transmission error is the same as the processing (S10 to S14) in FIG.

However, the judgment of (S10) is continuously negative (N
In the case of O), in the third embodiment, S21 and S22 are added after the process of (S15), and the processes of (S16) and S22 are performed according to the determination result of the determination process of S21. That is, (S
If the determination in 10) is negative (NO), the error counter 1
1 is performed ((S15)), and as a result, it is determined whether or not the count value of the error counter 11 is smaller than the specified value N of the encoded data buffer 15 in S21.

If the count value of the error counter 11 is smaller than the specified value N of the coded data buffer 15, the determination in S21 becomes affirmative (YES), and the background noise generation randomly selected in (S16). The background noise is reproduced based on the encoded data. On the other hand, in a situation where the number of consecutive occurrences of transmission errors exceeds the prescribed value N of the coded data buffer 15, the determination in S21 is negative (NO), and S22
The output of the white noise generator 19 is supplied to the background noise generator 16 to reproduce the background noise based on the white noise.

Even when the number of consecutive occurrences of transmission errors exceeds the prescribed value N of the coded data buffer 15, if the coded data for background noise generation is used in the same manner as in the first embodiment, repeated In some cases, the same coded data for background noise generation is used, and a periodic sound may be generated. The third embodiment aims to prevent this.

FIG. 14 is a block diagram of a fourth embodiment of the present invention (the block diagram of the background noise generation controller of the fourth embodiment). In the fourth embodiment, the previous frame power buffer 17 and the output power regulator 18 employed in the second embodiment are added to the third embodiment (FIG. 11). Therefore, the correspondence with claims 5 and 6 is the same as the correspondence with claims 2 and 3, and the description is omitted.

FIG. 15 is a flowchart of an embodiment corresponding to the fifth and sixth aspects. Hereinafter, the operation of the background noise generation controller according to the fourth embodiment will be described with reference to FIG.
In the fourth embodiment, the operation of the third embodiment (FIG. 1)
In 3), after the processing of (S16) and S22, (S17) to
The processing of (S20) is added. This processing is the same as the processing of S17 to S20 shown in the operation (FIG. 10) of the second embodiment.

Therefore, in a situation where the number of consecutive occurrences of transmission errors does not exceed the prescribed value N of the encoded data buffer 15,
Processing of S21 → (S16) → (S17) → (S18) → (S19) and S20 → (S1) are performed. The operation in this case is based on Equations (1) to
This can be explained by equation (5). Further, in the situation where the number of consecutive occurrences of transmission errors exceeds the specified value N of the encoded data buffer 15, S21 → S22 → (S17) → (S18) → (S19), S20
→ The processing of (S1) is performed.

In this case, let W be the white noise sequence, let Wn be the reproduced signal generated by this white noise sequence W, and let P _(k-1) be the frame power immediately before stored in the previous frame power buffer 17. If the power-adjusted reproduction signal V
n _(k) is as follows: Vn _(k) = Wn _(k) × P _(k−1) (6) Thereafter, the reproduced signal of Expression (6) becomes the background noise until the reception of the post pattern and the encoded data for generating the background noise is restored.

According to the above method, the post-pattern and coded data for generating background noise are continuously lost in a certain period or more, and the number of consecutive occurrences of transmission errors exceeds the prescribed value N of the coded data buffer 15. However, it is possible to switch to background noise based on white noise without generating a periodic sound, and to smoothly switch between frames.

Expression (6) relates to the frame power. However, similarly to the above description, a measure for calculating the sample average value of the frame power can be applied. Next, FIG. 16 is a configuration diagram of an embodiment corresponding to claims 7 and 8 (a configuration diagram of a background noise generation controller of a fifth embodiment). In the fifth embodiment, a previous frame reproduction signal buffer 20 and a variable gain adder 21 are added to the third embodiment (FIG. 11).

In FIG. 16, the output of the background noise generator 16 is connected to the previous frame reproduced signal buffer 20 and the variable gain adder 21. Previous frame playback signal buffer 2
The output of 0 is connected to the variable gain adder 21. Book 5
In the embodiment, the output of the background noise generator 16 is output to the direct switch 44 at the time of normal reception, and is output to the previous frame reproduction signal buffer 20 and the variable gain adder 21 at the time of a continuous error or at the time of return to normal reception thereafter. Is output.

Then, the background noise at the time of the continuous error or at the time of restoring the normal reception thereafter is output from the variable gain adder 21 to the switch 44. These controls are performed by the central control unit 14. Accordingly, the entirety of the previous frame reproduction signal buffer 20 and the variable gain adder 21 correspond to the variable gain addition means 7 of claims 7 and 8.

With the configuration of FIG. 16, the operation shown in FIG. 17 and the operation shown in FIG. 18 are performed. FIG. 17 is an operation flowchart according to the seventh embodiment. FIG. 18 is an operation flowchart of the embodiment according to the eighth aspect. First, the operation of the embodiment corresponding to claim 7 will be described with reference to FIG. In an embodiment corresponding to claim 7, the operation of the third embodiment (FIG. 1)
In 3), the processing of S23 and S24 is added after the processing of S22.

Therefore, under the situation where the number of consecutive occurrences of transmission errors does not exceed the prescribed value N of the encoded data buffer 15,
Processing of S21 → (S16) → (S1) is performed. On the other hand, in a situation where the number of consecutive occurrences of transmission errors exceeds the prescribed value N of the encoded data buffer 15, S21 → S22 → S23 → S2
4 → (S1) The process according to the present embodiment is performed.

That is, when the determination in S21 is negative (NO), the reproduction of the background noise is switched to the reproduction based on the white noise as described in the operation of the third embodiment (FIG. 13) (S22). However, at this time, it is determined in S23 whether or not the current use of the white noise is the first use. If the current use of the white noise is the first use, the determination in S23 is affirmative (YES), the process proceeds to S24, and the reproduction signal of the previous frame and the reproduction signal of the current generation frame are multiplied by a variable gain and added. This is output to the switch 44 as background noise. Thereafter, the flow returns to (S1) to prepare for the next reception.

On the other hand, if the current use of the white noise is not the first use, the determination in S23 is negative (NO). In this case, the variable gain adder 21 does not operate, and the output of the background noise generator 16 passes through the variable gain adder 21 and is output to the switch 44. Thereafter, the flow returns to (S1) to prepare for the next reception. In short, in S24, a sense of discomfort that may occur when switching from a reproduction signal (reproduction signal of the previous frame) based on the encoded data for background noise generation to a reproduction signal (reproduction signal of the current generation frame) based on white noise is obtained. In order to alleviate this, at the time of the switching, both the immediately preceding and succeeding ones are multiplied by a variable gain and added, and a process is performed such that the white noise sequence can be gradually shifted in the first frame.

The processing in S24 can be explained as follows. First, it is assumed that Expression (1) is satisfied. Further, as described above, the reproduced signal generated by the white noise sequence W is represented by W
n, and the reproduced signal based on the immediately preceding encoded data for background noise generation C _(k) is Cn _(k) , the reproduced signal Vn _(k) added by multiplying by the variable gain is given by the following equation (7). You can ask.

Vn _(k) = (1.0−m) Cn _(k) + mWn (7) where m = (1 / t) x. X is 0.0 ≦ x
≦ 1.0. That is, m monotonically increases from 0.0 to 1.0 for one frame length t seconds, and thereafter, is fixed at 1.0.

Thus, the first frame that shifts from the encoded data for background noise generation to the white noise sequence can be smoothly switched. Next, the operation of the embodiment corresponding to claim 8 will be described with reference to FIG. In the embodiment corresponding to claim 8, after (S9), S25
And the processing of S26 are added.

When a post pattern or the like is received without a transmission error, the processing of (S1) to (S9) is performed, and the background noise is reproduced based on the background noise coded data (S9).
In step 25, the contents of the determination in (S2) are confirmed. If the immediately preceding error counter 11 is not 0, the determination at S25 is negative (NO), and the process returns to (S1) via the process at S26. In this case, when the background noise is reproduced based on the white noise in a situation where there is a transmission error, the propagation path returns to normal, the transmission error disappears, and normal reception is performed first. Switching of the playback sound source may give a sense of incongruity.

In step S26, the reproduction signal generated by the white noise of the previous frame and the reproduction signal generated by the coded data for generating the background noise in the current frame are multiplied by a variable gain and added. Is output to the switch 44. Thereafter, the flow returns to (S1) to prepare for the next reception. The switching of the playback sound source is performed smoothly. On the other hand, if the immediately preceding error counter 11 is 0, S2
The determination of 5 is affirmative (YES). In this case, since the reproduction of the background noise based on the encoded data for generating the background noise is repeatedly performed, the variable gain adder 21
Does not operate, and the output of the background noise generator 16 passes through the variable gain adder 21 as it is and is output to the switch 44. Thereafter, the flow returns to (S1) to prepare for the next reception.

The processing in S26 can be explained as follows. First, it is assumed that Expression (1) is satisfied. Further, a reproduced signal generated by the white noise sequence W used for the immediately preceding background noise generation is denoted by Wn, and a reproduced signal based on the background noise generation coded data C _(k) received first after the transmission error recovery is performed. Assuming that Cn _(k) , the reproduced signal Vn _(k) added by multiplying by the variable gain can be obtained by the following equation (8).

Vn _(k) = (1.0−m) Wn + mCn _(k) (8) where m = (1 / t) x. X is 0.0 ≦ x
≦ 1.0. That is, m monotonically increases from 0.0 to 1.0 for one frame length t seconds, and thereafter, is fixed at 1.0. This makes it possible to smoothly switch the first frame that shifts from the white noise sequence to the background noise generation encoded data.

Next, FIG. 19 is a configuration diagram of an embodiment corresponding to claim 9 (configuration diagram of a background noise generation controller of a sixth embodiment). The background noise generation controller of the sixth embodiment differs from the fifth embodiment (FIG. 16) in that the variable gain adder 21 is replaced with an output power controller 18. In the embodiment corresponding to claim 9, the white noise generator 19 is not an essential element. Therefore, the second
In the configuration of the background noise generation controller of the embodiment (FIG. 9), a previous frame reproduced signal buffer 20 may be used instead of the previous frame power buffer 17.

That is, the output power adjuster 18 and the entirety of the previous frame reproduced signal buffer 20 correspond to the power adjusting means according to the ninth aspect. Next, FIG. 20 and FIG. 21 are operation flowcharts of the embodiment according to claim 9. FIG. 20 relates to a case where a post pattern or the like can be normally received, and FIG. 21 relates to a first normal reception when the state of the propagation path returns to normal.

When the reception state is restored from the state where the background noise was reproduced by the various methods described above under the situation where there is a transmission error, the reproduction signal based on the background noise generation encoded data received first after the restoration is restored. If there is a difference between the frame power and the frame power of the signal reproduced immediately before the restoration, the listener may feel uncomfortable.

In FIG. 20, when a post pattern or the like is received without transmission errors, the processing of S1 (S1) to S9 (S9) is performed, and the background noise is reproduced based on the encoded data for generating background noise. However, at this time, in S25, S2
Confirm the judgment contents of (S2). Last error counter 11
Is not 0, the determination in S25 is negative (NO), and the process returns to S1 (S1) via the power adjustment processing in S17 (S17) to S20 (S20) shown in FIG.

On the other hand, if the immediately preceding error counter 11 is 0, the determination at S25 is affirmative (YES). In this case, since the reproduction of the background noise based on the encoded data for background noise generation is repeatedly performed, the output of the background noise generator 16 is output from the output power adjuster 18 without performing the power adjustment processing. The light passes therethrough and is output to the switch 44. Thereafter, the process returns to S1 (S1) to prepare for the next reception.

This power adjustment processing is performed according to the above-described equations (1) to (1).
This is described by equation (6). As a result, the post-pattern transmission interval T seconds is required, and the background noise reproduced immediately before the transmission error is recovered can be smoothly shifted from the background noise generated by the background noise generation coded data received first after the recovery. .

[0109]

As described above, according to the first aspect of the present invention, in a silent section, encoded data for background noise generation is stored in a data buffer, and when a transmission error occurs and the transmission error continues, , The encoded data for background noise generation is temporally randomly selected and extracted from the data buffer,
Based on this, a signal equivalent to background noise is reproduced.

Therefore, even in a situation where a burst error occurs in which a specific pattern including the background noise generation coded data is lost, the same use of the same background noise generation coded data is reduced. Thus, a reproduced sound that does not cause abnormal noise and does not give a strange feeling to the listener can be obtained.

According to the second aspect of the present invention, a reproduced signal whose frame power is adjusted based on the difference between the frame power of the previous reproduced signal and that of the current reproduced signal is output. According to a third aspect of the present invention, a reproduced signal whose average power is adjusted based on the difference between the frame power sample average values of the previous and current reproduced signals is output. Therefore, according to the second and third aspects of the present invention, it is possible to smoothly switch the encoded data for background noise generation to be selected, so that it is possible to prevent the listener from feeling uncomfortable.

According to the fourth aspect of the present invention, in the silent section, the encoded data for background noise generation is stored in a data buffer, and when a transmission error occurs and continues, the number of consecutive occurrences of the transmission error is reduced. A magnitude relationship with the number of stored data is determined, and a sound corresponding to background noise is reproduced based on the coded data transmitted in the same manner as the invention according to claim 1 when the number of occurrences is equal to or less than the number of data. Is performed based on white noise when the number of occurrences is equal to or greater than the number of data.

Therefore, when the number of times of continuous error occurrence is larger than the number of stored data, in the first aspect of the present invention, there is a possibility that a periodic sound is generated, but this can be prevented. According to a fifth aspect of the present invention, when a sound source is switched under a situation where transmission errors continue to occur,
A reproduced signal whose frame power is adjusted based on the difference between the frame power of the reproduced signal generated by the immediately preceding encoded data for background noise generation and the subsequent reproduced signal generated by white noise is output.

The invention according to claim 6 is characterized in that, at the time of sound source switching performed in a situation where transmission errors continue to occur, the reproduction signal generated by the immediately preceding encoded data for background noise generation and the subsequent reproduced signal are generated. A reproduced signal whose average power is adjusted based on the difference between the reproduced signal generated by white noise and the average value of the frame power samples is output. According to a seventh aspect of the present invention, at the time of sound source switching performed in a situation where transmission errors continue to occur, a reproduction signal generated by the immediately preceding encoded data for background noise generation and a subsequent white noise generation A reproduced signal obtained by multiplying the reproduced signal by a variable gain and adding the resultant is output.

Further, according to the present invention, when a sound source is switched under a situation where a transmission error changes from presence to absence, the reproduced signal generated by the immediately preceding white noise and the subsequent background noise generation are used. A reproduced signal generated by multiplying the reproduced signal generated by the encoded data by a variable gain and adding the resultant is output.
According to the ninth aspect of the present invention, when data or a sound source is switched under a situation where a transmission error changes from presence to absence, the frame power of the reproduction signal generated immediately before the change and the reproduction signal generated after the change are changed. A difference from the frame power is obtained, and a reproduction signal of the power adjusted based on the difference is output.

Therefore, in the inventions according to claims 5 to 9,
Since the switching of the sound source and the like can be performed smoothly, it is possible to prevent the listener from feeling uncomfortable.

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the invention according to claim 1;

FIG. 2 is a principle block diagram of the invention according to claims 2 and 3;

FIG. 3 is a principle block diagram of the invention according to claims 4 to 6;

FIG. 4 is a principle block diagram of the invention according to claims 7 and 8;

FIG. 5 is a configuration diagram of a mobile wireless terminal device according to an embodiment of the present invention.

FIG. 6 is a configuration diagram of an embodiment corresponding to claim 1 (first embodiment);
FIG. 2 is a configuration diagram of a background noise generation controller according to the embodiment.

FIG. 7 is an operation flowchart of the embodiment corresponding to claim 1;

FIG. 8 is an operation flowchart of the embodiment corresponding to claim 1;

FIG. 9 is a configuration diagram of an embodiment corresponding to claims 2 and 3 (a configuration diagram of a background noise generation controller of a second embodiment);

FIG. 10 is an operation flowchart of the embodiment corresponding to claims 2 and 3;

FIG. 11 is a configuration diagram of an embodiment corresponding to claim 4 (a configuration diagram of a background noise generation controller of a third embodiment);

FIG. 12 is an operation flowchart of the embodiment according to claim 4;

FIG. 13 is an operation flowchart of the embodiment according to claim 4;

FIG. 14 is a configuration diagram of an embodiment corresponding to claims 5 and 6 (a configuration diagram of a background noise generation controller according to a fourth embodiment);

FIG. 15 is an operation flowchart of the embodiment corresponding to claims 5 and 6;

FIG. 16 is a block diagram of an embodiment corresponding to claims 7 and 8 (a block diagram of a background noise generation controller of a fifth embodiment);

FIG. 17 is a flowchart of an embodiment corresponding to claim 7;

FIG. 18 is a flowchart of an embodiment according to claim 8;

FIG. 19 is a configuration diagram of an embodiment corresponding to claim 9 (a configuration diagram of a background noise generation controller of a sixth embodiment);

FIG. 20 is a flowchart of an embodiment corresponding to claim 9;

FIG. 21 is a flowchart of an embodiment corresponding to claim 9;

FIG. 22 is a configuration diagram of a conventional mobile wireless terminal device.
(A) is a transmitting device. (B) is a receiving device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Background noise generation means 2 Data buffer 3 Judgment means 4, 4a, 4b Control means 5 Power adjustment means 6 White noise generation means 7 Variable gain addition means 10 Background noise generation controller 11 Error counter 12 Buffer counter 13 Pre / post pattern reception Unit 14 central control unit 15 coded data buffer 16 background noise generator 17 previous frame power buffer 18 output power controller 19 white noise generator 20 previous frame reproduced signal buffer 21 variable gain adder

Claims (9)

[Claims] 1. A mobile radio comprising a background noise generating means for receiving a specific pattern indicating a silent section inputted from a transmission path and generating a reproduction signal corresponding to the background noise based on the background noise generation coded data included therein. In the terminal device, a data buffer, a judging means for judging whether or not there is a transmission error in the characteristic pattern; While sequentially storing the coded data for background noise generation from the data buffer when the determination means continuously determines that there is a transmission error, A mobile radio terminal device comprising: a control unit for randomly selecting and extracting the background noise and providing the extracted background noise to the background noise generating unit. 2. The mobile radio terminal device according to claim 1, wherein, when the determination unit continuously determines that there is a transmission error, the background noise generation unit and the reproduction signal generated last time are generated. A mobile wireless terminal device comprising: a power adjustment unit that obtains a difference between frame powers of a reproduction signal and outputs a reproduction signal whose frame power is adjusted based on the difference. 3. The mobile radio terminal according to claim 1, wherein said background noise generating means generates a frame power sample of a reproduced signal generated last time when said determining means determines that there is a transmission error continuously. A mobile wireless terminal device comprising: a power adjusting unit that calculates a difference between an average value and a frame power sample average value of a reproduced signal generated this time and outputs a reproduced signal whose average power is adjusted based on the difference. 4. A moving apparatus comprising a background noise generating means for receiving a specific pattern indicating a silent section input from a transmission line, and generating and outputting a reproduced signal corresponding to the background noise based on the encoded data for generating background noise included in the specific pattern. In the wireless terminal device, a data buffer, white noise generating means for generating white noise, determining means for determining whether or not the specific pattern has a transmission error, and the determining means determines that there is no transmission error. The first control means for sequentially storing the encoded data for background noise generation in the data buffer and providing the data to the background noise generation means, and the determination means continuously determining that there is a transmission error. In the above, when the number of determinations does not exceed the number of data stored in the data buffer, the encoded data for background noise generation is read from the data buffer. Data is selected at random in time and given to the background noise generation means, and when the number of times determined to have a transmission error exceeds the number of data stored in the data buffer, the output of the white noise generation means is output. And a second control unit for providing the background noise generation encoded data to the background noise generation unit. 5. The mobile radio terminal device according to claim 4, wherein said background noise generation means generates a frame signal of a reproduction signal generated by immediately preceding encoded data for generating background noise and a reproduction signal generated by white noise thereafter. A mobile radio terminal device comprising: a power adjusting unit that obtains a difference from the frame power and outputs a reproduced signal in which the frame power is adjusted based on the difference. 6. The mobile radio terminal device according to claim 4, wherein said background noise generation means generates a frame power sample average value of a reproduction signal generated from immediately preceding encoded data for background noise generation and white noise thereafter. A mobile radio terminal device, comprising: a power adjusting means for calculating a difference between a frame signal sample average value of the reproduced signal and an average power adjusted based on the difference. 7. The mobile radio terminal device according to claim 4, wherein said background noise generation means variably changes a reproduction signal generated by immediately preceding encoded data for background noise generation and a reproduction signal generated by white noise thereafter. A mobile wireless terminal device comprising variable gain adding means for outputting a reproduction signal obtained by multiplying and adding a gain. 8. The mobile radio terminal device according to claim 4, wherein when the judgment means changes the judgment from the presence of a transmission error to the absence of a transmission error, the reproduction performed by the background noise generation means using the immediately preceding white noise. A mobile radio terminal apparatus comprising variable gain adding means for outputting a reproduced signal obtained by multiplying a signal and a reproduced signal generated by the encoded data for background noise generation by a variable gain and outputting the resultant signal. 9. The mobile radio terminal according to claim 1, wherein the background noise generation unit is configured to change the determination from the presence of a transmission error to the absence of a transmission error. A mobile radio terminal comprising: a power adjusting unit that calculates a difference between a frame power of a reproduced signal generated immediately before the change and a frame power of the reproduced signal generated after the change, and outputs a reproduced signal whose average power is adjusted based on the difference. apparatus.