JP2001265388A - Voice coding/decoding device and voice coding/decoding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a voice coding/decoding in proper timing even when the change of the delay of a signal transmission corresponding to the change of a transmission route with a mobile station device is generated. SOLUTION: The sound/silent state of a received PCM voice signal is discriminated in a sound discriminating part 104 and when the received PCM voice signal is in a sound state, a coding processing converting the signal into a high efficiency voice signal is performed in a voice coding part 105 and the high efficiency voice signal is continuously transmitted and when the PCM voice signal is in a silent state, a specific signal is generated to be intermittently transmitted and the operating timing of a coding processing is changed in a coding timing change instructing part 109 in a silent section in which the intermittent transmission is performed. Moreover, whether a received high efficiency voice signal is a voice signal which is intermittently transmitted or a signal being in sound state is discriminated in an intermittently received state discriminating part 112 and a decoding processing converting the high efficiency voice signal into a PCM signal is performed in a voice decoding part 113 in accordance with the discriminated result and the operating timing of this operation is changed in a silent section in which the intermittently transmitted high efficiency voice signal is received.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a base station controller for controlling a base station in a digital mobile communication system, a switching center connected to the base station controller by a line, and the like. Pulse Code Modulation) A speech encoding / decoding device for mutually converting a speech signal and a high-efficiency speech signal (compressed signal). Speech encoding / decoding apparatus and speech adopting a speech transmission method for intermittently transmitting a high-efficiency speech signal by transmitting a signal every frame, and when the speech is not at a significant level, as a silent section where no speech exists. The present invention relates to an encoding / decoding method.

[0002]

2. Description of the Related Art Conventionally, a speech encoding / decoding apparatus and a speech encoding / decoding method of this kind are disclosed in Japanese Patent No. 25185.
There is one described in Japanese Patent Application Publication No.

FIG. 4 is a block diagram showing a configuration of a conventional speech encoding / decoding device.

[0004] A speech coding apparatus 401 and a speech decoding apparatus 402 shown in Fig. 4 perform encoding / decoding by accommodating a plurality of channels of PCM speech signals. Shall be used.

[0005] A speech encoding device 401 converts a PCM speech signal into a high-efficiency speech signal, and includes a PCM signal receiving section 403, a sound determination section 404, and a speech encoding section 40.
5, a transmission signal generation section 406 during silence, a high-efficiency audio signal transmission section 407, an intermittent transmission control section 408, and an encoding timing control section 409.

The speech decoding apparatus 402 converts a high-efficiency speech signal into a PCM speech signal, and includes a high-efficiency speech signal receiving section 410, an intermittent reception state judging section 411, a speech decoding section 412, and a PCM speech signal. It comprises a signal transmission unit 413 and a decoding timing control unit 414.

In such a configuration, the operation of the speech encoding apparatus 401 will be described first.

[0008] A PCM audio signal transmitted from a switching center (not shown) via a PCM signal transmission path is received by PCM signal receiving section 403 and output to sound determination section 404.

The voiced / non-voiced state of the PCM audio signal is determined by the voiced / non-voiced state determination unit 404, and information on the voiced / silent state (voiced / silent information) is output to the intermittent transmission control unit 408. Are output to the voice encoding unit 405 and the silent transmission signal generation unit 406.

When the sound determination section 404 determines that there is a sound, the voice encoding section 405 converts the voice information into a high-efficiency voice signal by compressing the voice information with a predetermined algorithm. The signal is output to high-efficiency audio signal transmission section 407.

On the other hand, if it is determined that there is a silent state, the intermittent transmission control unit 408 instructs the silent transmission signal generation unit 406 to perform a silent process. In this processing, since no sound is superimposed on the sound information, a background noise signal is generated and the high-efficiency sound signal transmission unit 407 converts the background noise signal into a high-efficiency sound signal.

In the high-efficiency audio signal transmission section 407, the intermittent transmission control section 408 transmits a high-efficiency audio signal according to control corresponding to sound / non-sound information. That is, in the case of a sound state, the high-efficiency audio signal from the audio encoding unit 405 is transmitted from a base station apparatus (not shown) to a mobile station apparatus such as a mobile phone via a high-efficiency audio signal transmission path. If so, the high-efficiency audio signal from the silent transmission signal generation unit 406 is
It is transmitted intermittently (intermittent transmission) at predetermined time intervals.

The operation of each of the units 403 to 408 is as follows.
This is performed in synchronization with a timing control signal synchronized with the system clock signal output from the encoding timing control unit 409.

Here, the operation of the speech coding apparatus 401 when performing speech coding for accommodating PCM speech signals (PCM signals) of a plurality of channels will be described with reference to FIG.

As shown in FIG. 5, when accommodating three PCM signals of channels ch0 to ch2 received by the PCM signal receiving unit 403, for example,
Reference numeral 5 uses a frame period for encoding (encoded frame period) by time-dividing the timing control signal from the encoding timing control unit 409.

In this example, since 3 channels are accommodated, 3
Used separately. Assuming that the divided units are encoding sub-processing units A, B, and C, one set of encoding sub-processing units A, B, and C is accommodated in one frame, and the PCM signal accommodated in channel ch0. Always uses the encoding sub-processing unit A and the PCM accommodated in channel ch1.
The signal always uses the coding sub-processing unit B, the channel c
The PCM signal accommodated in h2 always uses the coding sub-processing unit C.

A high-efficiency audio signal obtained by performing encoding processing in these encoding sub-processing units A, B, and C is, for example, 20
It is transmitted from the high-efficiency audio signal transmission unit 407 every ms.

Next, with reference to FIG.
Operation 2 will be described.

The high-efficiency audio signal transmitted from the base station apparatus and the mobile station apparatus via the high-efficiency audio signal transmission path is received by the high-efficiency audio signal receiving section 410 and is controlled by the decoding timing control section 414 at the control timing. Output to intermittent reception state determination section 411.

When there is no sound, the decoding timing control section 41
In some cases, a high-efficiency audio signal is not received by the control timing of No. 4, and in that case, nothing is output to the intermittent reception state determination unit 411.

The intermittent reception state determination unit 411 determines from the input state whether the transmission state is an intermittent transmission state due to a silent state or a sound state, and this determination information is transmitted together with the received high-efficiency audio signal and the audio signal. Output to decoding section 412.

The voice decoding unit 412 performs a voice decoding process in a voiced state in a voiced state, and performs a process of generating background noise without a sense of discomfort in a voiceless state in a voiceless state. PCM signal is transmitted by the PCM signal transmitting section 41
3 to the exchange via the PCM signal transmission path.

The operation of each of the units 410 to 413 is as follows.
The decoding is performed in synchronization with a timing control signal synchronized with the system clock signal output from the decoding timing control unit 414.

Here, the operation in the case where the speech decoding apparatus 402 performs speech encoding for accommodating high-efficiency speech signals of a plurality of channels will be described with reference to FIG.

As shown in FIG. 6, for example, three channels ch0 to ch2 received by the high-efficiency audio signal
When accommodating a high-efficiency audio signal of a channel, the audio decoding unit 412 divides a frame period (decoding frame period) for decoding by time-dividing the timing control signal from the decoding timing control unit 414. To use. In this example, three channels are used to accommodate three channels.

Assuming that the three divided units are decoding sub-processing units A1, B1, and C1, one set of decoding sub-processing units A1, B1, and C1 is accommodated in one frame.
The high-efficiency audio signal accommodated in the channel ch0 always uses the encoding sub-processing unit A1, and the high-efficiency audio signal accommodated in the channel ch1 always uses the encoding sub-processing unit B1 and is accommodated in the channel ch2. High-efficiency audio signals always use the coding sub-processing unit C1.

These decoding sub-processing units A1, B1, C
1, the multiplexed PCM signal obtained by the decoding process is P
It is transmitted from the CM signal transmission unit 413.

In the mobile communication system, since the transmission timing of voice information in a wireless section is determined, a period from completion of voice coding to output of a signal to the radio or reception of a radio signal is performed. The timing of audio encoding / decoding is set so that there is no delay due to timing queuing from the start to the start of audio decoding.

[0029]

However, in the conventional apparatus, when switching of the base station apparatus accompanying the movement of the mobile station apparatus in the mobile communication system occurs,
For example, when handover occurs, the length of the signal transmission path changes, so that the audio encoding / decoding device 401,
The transmission delay time between the mobile station device 402 and the mobile station device may change.

In this case, there is a problem that even if the timing of speech encoding / decoding is optimized at the start of the operation, the transmission delay time changes, so that the timing may become inappropriate.

This is for performing speech encoding / decoding.
Encoding sub-processing unit A, B, C / decoding sub-processing unit A
1, B1 and C1 are processed in a predetermined order. For example, if the timing is shifted in A of a certain frame, the processing must be performed in A of the next frame. It can occur in both cases.
If such a timing shift occurs in the audio encoding / decoding process, the audio is transmitted with a delay, which causes a sense of hearing discomfort.

The present invention has been made in view of such a point, and even if a signal transmission delay changes according to a change in a transmission path with a mobile station apparatus, a speech encoding / decoding process is performed at an appropriate timing. It is an object of the present invention to provide an audio encoding / decoding device and an audio encoding / decoding method capable of performing the above.

[0033]

According to the present invention, there is provided a speech coding apparatus comprising: a judgment means for judging whether a received PCM speech signal is a sound state which is a sounding level of sound or a silent state which is not the sounding level; Encoding means for compressing the PCM audio signal to convert it to a high-efficiency audio signal in the case of the sound state; generating means for generating a specific signal to be transmitted intermittently in the case of the silent state; Transmitting means for continuously transmitting the high-efficiency audio signal in the case of a state, and transmitting means for intermittently transmitting the specific signal in the case of the silent state; control means for controlling operation timing of all the means; And an instructing means for instructing the control means to change the operation timing during a silent period.

According to this configuration, since there is a silent section of the transmitted speech signal, the operation timing of the speech encoding process is changed during that interval, thereby, for example, the transmission path between the speech encoding apparatus and the mobile station apparatus. Even if the signal transmission delay changes according to the change, it is possible to perform the audio encoding process at an appropriate timing.

[0035] In the speech encoding apparatus of the present invention, the encoding means may encode the PCM audio signal of a plurality of channels by performing the encoding processing of the PCM audio signal within a processing time determined by time division. And the operation timing of performing the encoding process of the PCM audio signals of the plurality of channels is changed according to the instruction of the instruction means.

According to this configuration, even if the speech encoding apparatus encodes PCM audio signals of a plurality of channels, speech encoding processing can be performed at appropriate timing.

A speech decoding apparatus according to the present invention comprises: a judging means for judging whether a received high-efficiency audio signal is intermittently transmitted or not in a sound state; Decoding means for converting the high-efficiency audio signal into a PCM signal in response thereto, transmitting means for transmitting the PCM signal, control means for controlling operation timing of all the means, and the intermittently transmitted high-efficiency signal. Instruction means for instructing the control means to change the operation timing in a silent section for receiving a voice signal.

According to this configuration, since there is a silent section of the transmitted audio signal, the operation timing of the audio decoding process is changed during that interval, thereby, for example, the transmission path between the audio decoding apparatus and the mobile station apparatus. Even if the signal transmission delay changes according to the change, it is possible to perform the audio encoding process at an appropriate timing.

In the audio decoding apparatus according to the present invention, the decoding means performs decoding of the high-efficiency audio signal within a processing time determined by time division so that a high-efficiency audio signal of a plurality of channels is provided. And the operation timing for performing the decoding processing of the high-efficiency audio signals of the plurality of channels is changed in accordance with the instruction of the instruction means.

According to this configuration, even if the audio decoding device decodes PCM audio signals of a plurality of channels, the audio decoding process can be performed at appropriate timing.

The digital signal processing device of the present invention employs a configuration including a voice coding device and a voice decoding device having the same configuration as any of the above.

According to this configuration, it is possible to obtain the same operation and effect as those of the speech encoding device or speech decoding device having the same configuration as any of the above.

In the digital signal processing device of the present invention, in the above configuration, since the PCM voice signal is near the boundary between the voiced / silent state, if the determination means in the voice coding device cannot properly determine, the voice decoding is performed. A configuration is employed in which the determination by the determination unit in the speech encoding device is performed using the determination result of the determination unit in the coding device.

According to this configuration, it is possible to more appropriately determine the sound / non-sound state of the PCM audio signal.

A voice processing system according to the present invention includes the voice coding apparatus having the above-described configuration, and a voice processing apparatus having the voice coding apparatus mounted thereon, and includes a silent section in which the voice coding apparatus performs intermittent transmission. Then, a configuration is adopted in which the speech encoding device is switched to the speech processing device.

According to this configuration, it is possible to switch the speech encoding device during the speech encoding process to the speech processing device.

A base station control apparatus according to the present invention comprises a speech decoding apparatus having the above-described configuration, and a speech processing apparatus equipped with the speech decoding apparatus. In the silent section for receiving an audio signal, a configuration is adopted in which the audio decoding device is switched to the audio processing device.

According to this configuration, it is possible to switch the speech decoding device during the speech decoding process to the speech processing device.

The base station control apparatus of the present invention employs a configuration including any one of the above-described voice coding apparatus, voice decoding apparatus, digital signal processing apparatus, and voice processing system.

According to this configuration, in the base station control device, it is possible to obtain the same operation and effect as any one of the voice coding device, the voice decoding device, the digital signal processing device, and the voice processing system having the same configuration as any of the above. it can.

The switching center apparatus according to the present invention employs a configuration including any one of the above-described voice coding apparatus, voice decoding apparatus, digital signal processing apparatus, and voice processing system.

According to this configuration, in the exchange apparatus,
It is possible to obtain the same operation and effect as any of the speech encoding device, speech decoding device, digital signal processing device, and speech processing system having the same configuration as any of the above.

The mobile communication system of the present invention employs a configuration including the base station control device or the switching center device having the above configuration.

According to this configuration, in the mobile communication system, it is possible to obtain the same operational effects as those of the base station control device or the exchange device having the above configuration.

The voice coding method according to the present invention uses
It is determined whether the M audio signal is a voiced state that is the sounding level of the voice or a silence state that is not the sounding level. If the result of the determination is the voiced state, the PCM voice signal is compressed into a highly efficient voice signal. Performs an encoding process for conversion, continuously transmits the processed high-efficiency audio signal, generates a specific signal to be transmitted intermittently in the case of the silent state, transmits the signal intermittently, and performs the silent transmission in which the intermittent transmission is performed. The operation timing of the encoding process is changed in a section.

According to this method, since there is a silent section of the transmitted audio signal, the operation timing of the audio encoding process is changed during that interval, thereby, for example, the transmission path between the audio encoding apparatus and the mobile station apparatus. Even if the signal transmission delay changes according to the change, it is possible to perform the audio encoding process at an appropriate timing.

The voice decoding method of the present invention determines whether a received high-efficiency voice signal is an intermittently transmitted one or a voiced state that is not so, and according to the determination result, Performing a decoding process of converting the high-efficiency audio signal into a PCM signal; transmitting the processed PCM audio signal; and performing the decoding process in a silent section in which the intermittently transmitted high-efficiency audio signal is received. Changed the operation timing.

According to this method, since there is a silent section of the transmitted voice signal, the operation timing of the voice decoding process is changed during that period, for example, to change the transmission path between the voice decoding apparatus and the mobile station apparatus. Even if the signal transmission delay changes according to the change, it is possible to perform the audio encoding process at an appropriate timing.

[0059]

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

(Embodiment) FIG. 1 is a block diagram showing a configuration of a speech encoding / decoding apparatus according to an embodiment of the present invention.

The voice coding apparatus 101 and the voice decoding apparatus 102 shown in FIG. 1 perform coding / decoding while accommodating a plurality of channels of PCM voice signals. Used and the same DSP (Digital
Signal Processor).

The voice coding apparatus 101 converts a PCM voice signal into a high-efficiency voice signal, and includes a PCM signal receiving section 103, a sound determination section 104, and a voice coding section 10.
5, a silence transmission signal generation unit 106, a high-efficiency audio signal transmission unit 107, an intermittent transmission control unit 108, an encoding timing change instruction unit 109, and an encoding timing control unit 1.
10 are provided.

The voice decoding apparatus 102 converts a high-efficiency voice signal into a PCM voice signal, and includes a high-efficiency voice signal receiving section 111, an intermittent reception state determining section 112, a voice decoding section 113, and a PCM voice signal. It comprises a signal transmitting unit 114, a decoding timing change instructing unit 115, and a decoding timing control unit 116.

In such a configuration, first, the operation of speech encoding apparatus 101 will be described.

A PCM audio signal transmitted from an exchange (not shown) via a PCM signal transmission path is received by PCM signal receiving section 103 and output to sound determination section 104.

The voiced / non-voiced state of the PCM audio signal is determined by the voiced / non-voiced state determination section 104, and information on the voiced / silent state (voiced / silent information) is output to the intermittent transmission control section 108. Is output to the voice encoding unit 105 and the silent transmission signal generation unit 106.

If the sound determination section 104 determines that the voice is in a sound state, the voice coding section 105 converts the voice information into a high-efficiency voice signal by compressing the voice information by a predetermined algorithm. The signal is output to high-efficiency audio signal transmission section 107.

On the other hand, if it is determined that there is a silent state, the intermittent transmission control section 108 instructs the silent transmission signal generating section 106 to perform a silent processing. In this process, since no voice is superimposed on the voice information, a background noise signal is generated and output to the high-efficiency audio signal transmission unit 107 as a high-efficiency audio signal.

In the high-efficiency audio signal transmission section 107, the intermittent transmission control section 108 transmits a high-efficiency audio signal in accordance with control corresponding to sound / no-sound information. That is, in the voiced state, the high-efficiency audio signal from the audio encoding unit 105 is transmitted from a base station apparatus (not shown) to a mobile station apparatus such as a mobile phone via a high-efficiency audio signal transmission path, and If so, the high-efficiency audio signal from the silent transmission signal generator 106 is
It is transmitted intermittently (intermittent transmission) at predetermined time intervals.

The operation of each of the units 103 to 108 is as follows.
This is performed in synchronization with a timing control signal synchronized with the system clock signal output from the encoding timing control unit 110.

In this case, the operation in the case where the speech encoding apparatus 101 performs speech encoding for accommodating PCM speech signals (PCM signals) of a plurality of channels has been described with reference to FIG. The same is true.

That is, when accommodating the PCM signals of the three channels ch0 to ch2 received by the PCM signal receiving unit 103, the speech encoding unit 105 transmits the frame cycle (encoding frame cycle) for encoding. ) Is time-divided (divided into three) by the timing control signal from the encoding timing control unit 110, and encoding processing is performed in the three divided encoding sub-processing units A, B, and C.

Next, the operation of the speech coder 101 when the speech processing timing is changed, for example, when handover occurs due to the movement of the mobile station apparatus will be described.

When the audio processing timing is changed,
An operation timing change instruction signal is transmitted from the exchange via the device control interface to the encoding timing change instruction unit 10.
9 is input.

In this case, the encoding timing change instructing section 109 receives information from the intermittent transmission control section 108 as to whether or not the apparatus is in the silent state, that is, the state of intermittent transmission, and the received information is in the intermittent transmission state. , The encoding timing control unit 110 is instructed to change the phase of the timing control signal, that is, to change the operation timing of the speech encoding device 101.

A description will now be given, with reference to FIG. 2, of a change in the operation timing of speech coding in accordance with this instruction.

As shown in FIG. 2, in speech encoding section 105, in the encoding sub-processing unit A, encoding processing of the PCM audio signal of channel ch0 received by PCM signal receiving section 103 is performed. The other encoding sub-processing units B and C are empty.

In the high-efficiency audio signals of frames 1, 2, and 3 of channel ch0 output from audio encoding section 105, there is no audio data because there is no sound in this case.
Therefore, for example, if an encoding timing change instruction is received in frame 2, from frame 3 of channel ch0,
The coding process of channel ch0 is changed to coding sub-processing unit B.

At the time of changing the operation timing, between the PCM audio signals of frame 2 and frame 3, reference numeral 20
Although a signal section that is not processed occurs as shown in FIG. 1, there is almost no auditory effect due to silence.

Next, with reference to FIG.
Operation 2 will be described.

The high-efficiency audio signal transmitted from the mobile station apparatus via the base station apparatus and the high-efficiency audio signal transmission path is received by the high-efficiency audio signal receiving section 111, and the high-efficiency audio signal receiving section 111 receives the high-efficiency audio signal at the control timing of the decoding timing control section 116. Output to intermittent reception state determination section 112.

When there is no sound, the decoding timing control unit 11
In some cases, a high-efficiency audio signal is not received by the control timing of No. 6, and in that case, nothing is output to the intermittent reception state determination unit 112.

The intermittent reception state determination unit 112 determines from the input state whether the state is an intermittent transmission state due to a silent state or a sound state, and this determination information is transmitted together with the received high-efficiency audio signal and the audio signal. Output to decoding section 113.

The speech decoding unit 113 performs a speech decoding process in a sound state in a sound state, and performs a process of generating background noise without a sense of hearing discomfort in a silent state. PCM signal transmitting section 11
4 to the exchange via the PCM signal transmission path.

The operation of each of the units 111 to 114 is as follows.
The decoding is performed in synchronization with a timing control signal synchronized with the system clock signal output from the decoding timing control unit 116.

Here, the operation in the case where the speech decoding apparatus 102 performs speech encoding for accommodating high-efficiency speech signals of a plurality of channels is the same as that described with reference to FIG. 6 in the conventional example.

That is, when accommodating three high-efficiency audio signals of the channels ch0 to ch2 received by the high-efficiency audio signal receiving unit 111, the audio decoding unit 113 transmits the frame cycle ( Decoding frame period)
Is time-divided (divided into three) by the timing control signal from the decoding timing control unit 116, and the decoding process is performed on the three divided decoding sub-processing units A1, B1, and C1.

Next, the operation of the speech decoding apparatus 102 when the speech processing timing is changed, for example, when handover occurs due to the movement of the mobile station apparatus will be described.

When the audio processing timing is changed,
An operation timing change instruction signal is sent from the exchange via the device control interface to the decoding timing change instruction unit 11.
5 is input.

In this case, decoding timing change instructing section 115 receives information as to whether or not it is in the silent state, ie, the state of intermittent reception, obtained by the determination in intermittent reception state determining section 112, and the received information is In the case of the intermittent reception state, the phase of the timing control signal is changed for the decoding timing control section 116, that is, the speech decoding apparatus 1
02, the instruction to change the operation timing is issued.

The change of the operation timing of speech decoding according to this instruction will be described with reference to FIG.

As shown in FIG. 3, in the audio decoding section 113, the encoding processing of the high-efficiency audio signal of the channel ch0 received by the high-efficiency audio signal receiving section 111 is performed in the encoding sub-processing unit A1. Thus, the other encoding sub-processing units B1 and C1 are empty.

In this case, the high-efficiency audio signals of frames 2 and 3 of channel ch0 have no audio data because they are silent in this case. Therefore, for example, if an encoding timing change instruction is received in frame 3, the encoding process of channel ch0 is changed from frame 3 of channel ch0 to encoding sub-processing unit B1.

When changing the operation timing, the PC
As shown by reference numeral 301, it is necessary to embed a silent signal between the PCM signals of frame 2 and frame 3 output to the M signal transmitting unit 114. This is to fill a blank period during which no PCM signal is output due to a change in operation timing. Since this section originally has no sound, it is sufficient to fill the section with a silent signal.

As described above, the speech encoding /
According to the decoding devices 401 and 402, since there is a silent section in the transmitted audio signal, the operation timing of the audio encoding / decoding processing is changed during that period to prevent a change in the transmission path with the mobile station apparatus. Even if a corresponding change in signal transmission delay occurs, speech encoding / decoding processing can be performed at appropriate timing.

Also, in the above embodiment, in the speech encoding / decoding device, the speech encoding device 101 and the speech decoding device 102 separately determine whether or not speech is sound. However, in the voice conversation, when one person speaks, one person often listens,
The determination result of the coded signal of the sound determination unit 104 in the encoding process and the intermittent reception state determination unit 11 in the decoding process
The determination may be made based on the determination result of the second decoded signal.

This is because the state of the coded signal determined by the voiced determination unit 104 is near the boundary between voiced and silent.
If any of them cannot be determined accurately, the intermittent reception state determination unit 1
In 12, if it is determined that the high-efficiency audio signal is not intermittent reception, that is, it is determined that the voice signal is in a voiced state, it is known that the coding process on the transmission side has been in the voiced state until then.
At the boundary, it can be estimated that the sound is to be switched to the silent state, and from this estimation, the determination result of the sound determination unit 104 can be set to the silent state.

Thus, it is possible to improve the accuracy of the determination of the sound / non-speech state.

In the above embodiment, when a signal transmission delay changes according to a change in the transmission path between the speech encoding / decoding devices 101 and 102 and the mobile station device, the same DSP is used. Although the description has been given of changing the operation timing, for the purpose of maintenance such as replacing a part of the voice encoding / decoding devices 401 and 402, the voice processing is performed by another DSP or the like during the current voice encoding / decoding processing. When transferring to an audio processing device or the like, the shift timing can be performed in a section where there is no audio data (transmission signal) in a silent section as described in the above embodiment.

Thus, during speech encoding / decoding processing, speech encoding / decoding devices 101 and 102 can be partially replaced like speech encoding device 101 and speech decoding device 102. It becomes possible.

[0101]

As described above, according to the present invention,
Even if the signal transmission delay changes according to the change in the transmission path with the mobile station device, the voice encoding / decoding process can be performed at appropriate timing.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a speech encoding / decoding device according to an embodiment of the present invention.

FIG. 2 is a timing chart for explaining a process of changing the operation timing of the speech coding apparatus according to the embodiment.

FIG. 3 is a timing chart for explaining a process of changing the operation timing of the speech decoding apparatus according to the embodiment.

FIG. 4 is a block diagram showing a configuration of a conventional speech encoding / decoding device.

FIG. 5 is a timing chart for explaining a process of changing the operation timing of the conventional speech coding apparatus.

FIG. 6 is a timing chart for explaining a process of changing the operation timing of a conventional speech decoding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Speech coding apparatus 102 Speech decoding apparatus 103 PCM signal receiving part 104 Voice existence judgment part 105 Speech coding part 106 Silent transmission signal generation part 107 High efficiency sound signal transmission part 108 Intermittent transmission control part 109 Coding timing change instruction Unit 110 Encoding timing control unit 111 High-efficiency audio signal receiving unit 112 Intermittent reception state determining unit 113 Audio decoding unit 114 PCM signal transmitting unit 115 Decoding timing change instructing unit 116 Decoding timing control unit

Claims (13)

[Claims] 1. A determining means for determining whether a received PCM audio signal is a voiced state that is a sounding level of voice or a silent state that is not the sounding level, and compresses the PCM voice signal in the case of the voiced state. Encoding means for converting to a high-efficiency audio signal, generating means for generating a specific signal to be transmitted intermittently in the case of the silent state, and continuously transmitting the high-efficiency audio signal in the case of the sound state Transmitting means for intermittently transmitting the specific signal in the case of the silent state, control means for controlling operation timings of all the means, and control means for changing the operation timing during a silent period in which the intermittent transmission is performed. And an instructing means for instructing the speech encoding. 2. The encoding means encodes a PCM audio signal in a plurality of channels by performing an encoding process on the PCM audio signal within a processing time determined by time division.
2. The speech encoding apparatus according to claim 1, wherein an operation timing of performing encoding processing of the PCM speech signals of the plurality of channels is changed according to an instruction of an instruction unit. 3. A determination means for determining whether a received high-efficiency audio signal is intermittently transmitted or a sound state in which the high-efficiency audio signal is not transmitted, and said high-efficiency audio signal is determined according to the determination result. To a PCM signal; a transmitting means for transmitting the PCM signal; a control means for controlling the operation timing of all the means; and a silent section for receiving the intermittently transmitted high-efficiency audio signal. Instruction means for instructing the control means to change the operation timing,
A speech decoding device comprising: 4. The decoding means performs decoding of a high-efficiency audio signal in a plurality of channels by performing decoding of a high-efficiency audio signal within a processing time determined by time division,
4. The audio decoding apparatus according to claim 3, wherein an operation timing for performing decoding processing of the high-efficiency audio signals of the plurality of channels is changed according to an instruction of an instruction unit. 5. A digital signal processing device comprising the speech encoding device according to claim 1 or 2, and the speech decoding device according to claim 3 or 4. 6. Since the PCM audio signal is near a boundary between a voiced state and a silent state, and cannot be properly judged by the judging means in the speech coding apparatus, the judgment result of the judging means in the speech decoding apparatus is used. 6. The digital signal processing device according to claim 5, wherein the determination by the determination means in the speech coding device is performed. 7. An audio encoding device according to claim 1, comprising: an audio processing device equipped with the audio encoding device.
An audio processing system, wherein the audio encoding device is switched to the audio processing device in a silent section in which intermittent transmission is performed by the audio encoding device. 8. An audio decoding device according to claim 3, further comprising: an audio processing device equipped with the audio decoding device.
An audio processing system, wherein the audio decoding apparatus switches the audio decoding apparatus to the audio processing apparatus in a silent section in which the intermittently transmitted high-efficiency audio signal is received. 9. A speech encoding device according to claim 1 or 2, a speech decoding device according to claim 3 or 4, a digital signal processing device according to claim 5 or 6, and 7. A base station control device, comprising: the voice processing system according to claim 8. 10. The speech encoding device according to claim 1 or 2, the speech decoding device according to claim 3 or 4,
The digital signal processing device according to claim 5 or 6,
An exchange device, comprising: the voice processing system according to claim 7. 11. A mobile communication system comprising the base station control device according to claim 9 or the switching center device according to claim 10. 12. A determination is made as to whether the received PCM audio signal is a sound state, which is the sound level of the sound, or a silent state, which is not the sound level. Performs an encoding process of compressing and converting to a high-efficiency audio signal, continuously transmitting the processed high-efficiency audio signal, generating a specific signal to be intermittently transmitted in the case of the silent state, and performing intermittent transmission. And changing the operation timing of the encoding process during a silent section in which the intermittent transmission is performed. 13. A method for determining whether a received high-efficiency audio signal is an intermittently transmitted signal or a non-intermittent sound state, and converting the high-efficiency audio signal into a PCM signal in accordance with a result of the determination. Performing a decoding process of converting the PCM audio signal thus processed, and changing the operation timing of the decoding process to a silent section in which the intermittently transmitted high-efficiency audio signal is received. Characteristic speech decoding method.