JPH09139978A - Sound signal transmitter-receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To listen to not only the sound from a called party but also the sound for which a memo recording is performed in process of a speech by means of a portable telephone set with a memo recording function. SOLUTION: A compression encoding is performed for an inputted sound signal in a speech encoder part 3, the signal is transmitted to a RF transmission processing part 4, a channel encode, a modulation and a transmission processing are performed for the signal and the signal is transmitted via an antenna 11. After a reception processing, a demodulation and a channel decode processing are performed for the signal received via the antenna 11 in a RF reception processing part 5, an extension decoding is performed in a speech decoder part 6. In a memory 7, the sound parameter from a speech encoder part 3 is stored in waiting or the sound parameter from a speech encoder part 3 or the RF reception processing part 5 is stored in process of a speech, by a recording/reproducing control part 8. A speech decoder part 6 is the sound decoder of two channels, decodes each of the recording sound parameter from the memory 7 and the reception sound parameter from the speech encoder part 3 in process of the speech and makes the both of the sound heard on the side of a user.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice signal transmitting / receiving apparatus using a wireless telephone line such as an automobile telephone and a portable telephone, and is particularly preferably applied to a digital wireless telephone line telephone for transmitting / receiving digital data. The present invention relates to a transmitting / receiving device.

[0002]

2. Description of the Related Art As a mobile communication telephone using a wireless telephone line, for example, various automobile telephones and mobile telephones have been developed. Although communication systems using analog communication are known for these car phones and mobile phones, in recent years, phones using digital wireless lines that perform communication by wireless transmission of digital data have become widespread.

The digital radio telephone apparatus has an advantage that the bit rate can be lowered by performing various high-efficiency encoding processing on voice, and consequently the bandwidth of the communication channel can be narrowed and the number of lines can be increased. Moreover, the applicant of the present application has previously proposed a technique for saving the recording time by recording the voice parameter coded with high efficiency.
It is proposed by the specification of No. 154776, drawings, and the like.

[0004]

By the way, a voice signal of a wireless telephone device or the like provided with a "memo function" for recording one's own voice during standby or recording one's own or other party's voice during a call as described above. In the transmitting / receiving device, the voice parameter can be supplied to the speech decoder when the voice is reproduced during standby, and the voice can be decoded and heard, but when the voice is reproduced during the call, the recorded voice can be heard by the other party. Even if you can, you can only listen to either the received voice sent from the other party or the recorded voice.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a voice signal transmitting / receiving apparatus that allows not only the other party but also the person himself / herself to listen to the recorded voice during a call.

[0006]

In order to solve the above-mentioned problems, a voice signal transmitting / receiving apparatus according to the present invention compresses and encodes an output signal from a receiving means and / or an input voice signal. Storing the output signal from the means in the storage means, and performing the extension decoding on the output signal from the receiving means and the output signal from the storage means by the extension decoding means and outputting the voice signal during the call. Is characterized by. The storage means may store its own voice in the form of compression-encoded voice parameters during standby, or store the voice of oneself or the other party in the form of compression-encoded voice parameters during a call. To be

Thus, even during a call, the voice sent from the other party and the voice stored in the storage means can be heard at the same time.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An audio signal transmitting / receiving apparatus according to a preferred embodiment of the present invention will be described below with reference to the drawings. As the voice signal transmitting / receiving apparatus, an example of a mobile phone according to a full-duplex method suitable for application to, for example, digital cellular, that is, a duplex system for performing mutual communication by simultaneous transmission / reception will be described. This mobile phone is used as a terminal and communicates with a base station by exchanging digital data in which a voice signal is highly efficiently encoded and compressed.

In the mobile phone shown in FIG. 1, a voice signal on the transmitting side is converted into an electric signal via the microphone 1 in order to make it a transmission signal. The electric signal from this microphone 1 is A
It is supplied to the / D converter 2.

This mobile phone includes a speech encoder section 3 for compressing and encoding an output signal from the A / D converter 2 as an input voice signal, and an RF for performing transmission processing on the output signal from the speech encoder section 3. A transmission processing unit 4, an RF reception processing unit 5 that performs reception processing on the modulated input signal supplied to the reception side, and an output signal from the RF reception processing unit 5 is expanded and decoded to output a voice signal. A speech decoder section 6, a semiconductor memory 7 for recording a transmission / reception signal from the speech encoder section 3 and / or to the speech decoder section 6, and a recording / reproduction control section 8 for controlling the semiconductor memory 7 according to the transmitted / received signal. And have.

Further, the speech decoder section 6 supplies the decompressed and decoded signal to the D / A converter 9. D / A
The converter 9 converts a digital signal supplied from the other party of communication into an analog signal and outputs the analog signal to the speaker 10.
The speaker 10 converts the supplied analog signal into voice. In this manner, the mobile phone performs a signal processing and transmission of a voice signal to a communication partner and receives a voice from the partner to talk.

Next, the structure of each part will be briefly described.

The speech encoder section 3 comprises a speech encoder circuit 3a and a changeover switch SW1. The speech encoder unit 3 performs high-efficiency coding processing on the digital data supplied from the A / D converter 1, and supplies the coded data such as the obtained coding parameters to the RF transmission processing unit 4. This changeover switch SW1
Selects the recording / reproducing side of audio by a switching signal supplied in response to a user's operation of a key switch mounted on a mobile phone.

As a compression coding method used in the speech encoder circuit 3a of the speech encoder unit 3, there are statistical characteristics in the time domain and frequency domain of an audio signal (including a voice signal and an acoustic signal) and human hearing. Various encoding methods are known in which signal compression is performed by utilizing the characteristics of. This coding method can be roughly classified into coding in the time domain, coding in the frequency domain, and analysis / synthesis coding.

As a specific example of high-efficiency encoding of a voice signal, MBE (Multiband Excitation) encoding, Harmonic encoding, SBC (Sub-Sub-encoding).
bandCoding: Band division coding, LPC (Linear Predic)
tive Coding: Linear predictive coding), DCT (discrete cosine transform), MDCT (modified DCT),
FFT (Fast Fourier Transform) and the like can be mentioned. In these encoding, various information data such as spectrum amplitude and its parameters (LSP parameter, α parameter, k parameter, etc.), more generally code data Is used. In recent years, CELP
(Code Excited Linear Predictive) coding and VSELP (Vector Sum Excited Linea)
r Predictive: Vector sum excitation linear prediction) coding, PS
I (Pitch Synchronus Inovation) -CELP encoding,
Alternatively, RPE-LTP (Regular Pulse Excitation-Lon) which is a kind of multi-pulse excitation linear predictive speech coding
g Term Prediction) encoding and the like are also known as voice encoding methods for digital mobile phones, and may be used for the speech encoder circuit 3a of the speech encoder unit 3. In the following description, the coded data obtained by the various types of voice coding as described above will be described by using voice parameters or parameters as a representative.

Next, the RF transmission processing unit 4 includes a channel encoder 4a, a modulation circuit 4b, and an RF transmission processing circuit 4
It is composed of c and.

The RF transmission processing unit 4 has a high-efficiency-encoded and compressed digital data having the above-described configuration, that is, code data such as a voice parameter is modulated by the modulation circuit 4b via the channel encoder 4a. 4c transmits as an RF signal from the antenna 11 to the base station.

Also, the mobile phone has an antenna 11
The RF signal is supplied from the base station to the RF reception processing unit 5 via the. The RF reception processing unit 5 includes an RF reception processing circuit 5
a, a demodulation circuit 5b, and a channel decoder 5c.

In the RF reception processing section 5, for example, the received R
The F signal is subjected to signal processing relating to reception by the RF reception processing circuit 5a and is supplied to the demodulation circuit 5b. Demodulation circuit 5b
Performs equalizer processing on the signal from the RF receiving circuit 5a to shape the waveform and supplies it to the channel decoder 5c. The channel decoder 5c uses, for example, a voice activity flag (Voice Activity F) from the downlink side.
lag) is supplied to the recording / reproduction control unit 8 and digital code data compressed by high efficiency encoding, that is, voice parameters and the like are supplied to the speech decoder unit 6.

The speech decoder section 6 includes a changeover switch S.
It is composed of W2 and a speech decoder 6a. Similarly to the changeover switch SW1, the changeover switch SW2 is also used to select the recording / reproducing side of the sound by the changeover signal supplied in response to the user's operation of the key switch attached to the mobile phone. In the speech decoder section 6, the compressed high efficiency encoded digital data,
That is, the voice parameters and the like (more generally, coded data) are decompressed, decoded, and output to the D / A converter 9. The D / A converter 9 converts the supplied digital data into an analog signal and supplies it to the speaker 10 of the handset. As a result, the speaker 10 converts the voice signal from the communication partner side to generate a sound.

The recording / reproducing control unit 8 is constructed by using a CPU or a DSP, and a semiconductor memory such as a RAM is used. Recording / reproduction is performed on the memory 7 under the control of the recording / reproduction control unit 8. As the memory 7, for example, a memory having a capacity capable of recording for N seconds is provided.

The recording / playback control unit 8 has the compressed audio parameters from the speech encoder circuit 3a,
The compressed speech parameters are supplied to the speech decoder circuit 6a. The recording / reproducing control unit 8 is supplied with a voice activity flag (Voice Activity Flag) for notifying the presence / absence of an audio signal during the recording / reproducing from the speech encoder circuit 3a and the channel decoder 5c, respectively. The recording / playback control unit 8 performs voiced / silent selection recording control for the voice parameter supplied based on the voice activity flag.

Here, when the recording / reproduction control section 8 detects the level of the audio signal based on the output signals from the A / D converter 2 and the speech decoder circuit 6a, respectively, this recording / reproduction control section No. 8 makes the voice activity flag unnecessary. Further, the recording / reproduction control unit 8
However, when the level can be detected from the compressed audio parameter, the A / D converter 2 and the speech decoder circuit 6 are respectively provided.
The output signal from a is also unnecessary. Recording / reproduction control unit 8
Supplies the compressed audio parameters supplied to the memory 7 to control recording.

Next, the recording function of this mobile phone will be described with reference to the flowchart of FIG. The configuration of FIG. 1 is also referred to as necessary.

The mobile phone has the state of the recording function itself. For example, in the non-recording state, the state value st
Is 0 (st = 0). In the recording state, the state value is set to a value other than 0.

First, when a user request signal, in this case, a recording request signal, is supplied from the user of the mobile phone to the recording / playback control section 8 by key operation, whether the signal is one-way or two-way in response to the recording request signal. Is set to a predetermined position. After this, a recording routine which is a subroutine is called.

The called recording routine checks the state of the recording function in step S2 of FIG. Step S
In 2, when the current state st is 0 (Yes), the process proceeds to step S3. If the current state st is not 0 (No), the process proceeds to step S4.

In step S3, the recording pointer (rp) for recording is initialized, the value fc of the frame counter is set to 0 (fc = 0), and then the next step S3.
Proceed to 4.

In step S4, the state value st is set to 1
After only stepping (st ++), the process proceeds to step S5. In this step S4, the state value st may be set to 1 (st = 1). Next step S5
Then, 1 (hd = 1) which means that data exists is set in the header hd of the audio parameter.

In the next step S6, the voice parameter on the uplink side or the downlink side is recorded in the memory 7 in response to the user's request.

Here, the recording structure for recording in the memory 7 will be described.

Generally, coded data, for example, a voice codec parameter or a voice parameter is treated as an aggregate of parameters having a data amount of several bits.
Generally, since the data is recorded in the memory with a width of 8 bits / 16 bits, it is possible to expect a data compression effect by recording in a format suitable for the bit length.

FIG. 3 shows a specific example of voice parameters recorded in the memory 7, more generally, code data. In this example, the RPE-LTP (Regular Pulse Ex
citation-Long Term Prediction) is shown.

That is, in FIG. 3, (A) is the above R
PE-LTP encoding type speech encoder circuit 3a
The frame parameters obtained for each frame of the encoding are shown, and LAR1 to LAR8 in the figure are codes obtained by logarithmically quantizing the reflection coefficient obtained by performing the short-term prediction analysis on the input signal. When recording or storing these eight parameters LAR1 to LAR8 in the memory 7, as shown in FIG. 3B, the parameters LAR5 and LAR6 are respectively stored in a 1-byte storage area.
By writing the parameters LAR7 and LAR8, the size of the storage area of the eight parameters is compressed to 6 bytes.

Further, FIG. 3C shows subframe parameters obtained for each subframe obtained by dividing one frame into four. The parameter Nn is the pitch period obtained between the shaped prediction residual signal and the past reproduced residual signal of the nth subframe (n = 1 to 4), and the parameter bn is the pitch of the nth subframe. The encoded long-term prediction filter coefficient obtained from the cycle Nn is set as the parameter M.
n is the grid position of the pulse train selected from the four RPE pulse trains thinned out from the long-term prediction residual signal in the nth subframe, and the parameter Xmaxn is selected from the above parameters Mn in the nth subframe. The parameter Xn (0) to Xn (12) is a code obtained by logarithmically quantizing the maximum amplitude of the RPE pulse train, and the RPE pulse train is normalized and quantized with the maximum amplitude obtained from the parameter Xmaxn of the nth subframe. The respective symbols are shown. When recording or storing such 17 parameters in the memory 7, it is necessary to provide a portion for writing two parameters in a 1-byte storage area as shown in FIG. The storage capacity that is said to be compressed to 9 bytes.

Further, by setting the header as a part of the recording structure inside the memory 7, the contents of the frame parameter and the sub-frame parameter can be known.

In the header of this recording structure, as shown in FIG. 4, for example, the least significant 1 bit indicates the presence or absence of recording data. That is, as shown in FIG. 4, when the least significant bit is set to "1", it indicates that the voice parameter is recorded in the memory 7. When "0" is set in the least significant bit, it indicates that there is no record data.

Next, returning to FIG. 2 again, after the voice parameters are recorded in step S6, the process proceeds to step S7, the value fc of the frame counter is incremented by 1, and the process proceeds to step S8. In step S8, the value rp of the recording pointer is updated, and the process proceeds to step S9.

In step S9, it is determined whether or not there is a recording stop request from the user supplied via an external controller or the like. If there is no recording stop request (No), the process proceeds to step S10. If there is a recording stop request (Yes), the process proceeds to step S11.

In step S10, it is determined whether or not the value fc of the frame counter has reached a count value when recording for N seconds, that is, LIMIT. When the value of the frame counter has not reached LIMIT (No), this processing routine is ended. In addition, when the value fc of the frame counter has reached LIMIT (Yes
s), and proceeds to step S11.

In step S11, the recording / reproducing control unit 8
To a mobile phone control unit (eg CP
The end flag supplied to U) is set, the state value st is set to 0, the header value n_hd of the next frame is set to 0, and this recording routine is ended. Note that the value of the header of the next frame is set to 0 in consideration of the fact that it is sufficient to reproduce until the header reaches the frame of 0 at the time of reproduction.

Furthermore, by performing voice detection by a voice activity flag or the like, it is possible to consider recording for a longer period of time, or to prevent missing of the beginning or ending of the voice to be pronounced, which gives a feeling of strangeness during reproduction. You can avoid it.

By the recording operation as described above, the own voice is stored in the memory 7 in the form of highly efficient coded voice parameters during standby, and during the call, the voice of the user or the other party is recorded. Can be stored in the form of highly efficient coded speech parameters.

Next, the reproducing function of this portable telephone will be described with reference to the flowchart of FIG. 5 and the block diagram of the main part of FIG. Refer to FIG. 1 and the like as necessary.

The mobile phone stores data from the memory 7 in FIG.
A switch SW2 for selecting a voice parameter supplied via the reproduction function unit of the reproduction control unit 8, more generally code data, and a speech of the speech decoder unit 6 for restoring the supplied voice parameter into a voice signal. Audio is reproduced using the decoder circuit 6a.

The speech decoder unit 6 is provided with a block for acquiring a voice parameter from the memory 7 and a block for restoring the voice parameter to the original voice. In both of these blocks, a shared memory space is provided on the RAM as a voice parameter buffer. The RAM processing corresponding to the former block is writing, and the RAM processing corresponding to the latter block is reading. Here, in the present embodiment, only the former writing process is called a reproduction function (reproduction routine) in the mobile phone. A subroutine that realizes this function is a reproduction routine described below.

The reproducing routine also has the state of the reproducing function itself as in the case of the recording routine described above. The value st of this state has a value of 0 in the state indicating the non-reproduction state and a value other than 0 in the state indicating the reproduction state.

Further, in this embodiment, a two-channel decoder is used during a call, one for reproducing a received voice parameter and another for reproducing a recorded voice parameter. FIG. 6 is a conceptual block diagram for explaining the reproduction processing of the speech decoder unit 6, and an audio parameter buffer 6b for exchanging audio parameters is provided between the switch SW2 and the speech decoder 6a. Since it is necessary to move the 2-channel audio decoder, a save area 6c for holding the other filter state and the output audio is provided. The output voice held and output in the output buffer of the save area 6c is digitally added by the adder 6d to the output voice from the output buffer of the speech decoder 6a and taken out. A switch 6e is inserted between the output buffer of the save area 6c and the adder 6d, and is turned on / off by a control signal from the recording / playback control unit 8.

At the time of reproduction, the state value st of the recording / reproduction control section 8 is initialized to 0 in the same manner as at the time of recording, and the user request signal is recorded through the control unit of the portable telephone by the user's key operation. / When supplied to the reproduction control section 8, first, in step S22, the state of the reproduction function is checked. In step S22, if the value st of the current state is 0 (Yes), the process proceeds to step S23, and if the value st of the current state is not 0 (No), the process proceeds to step S24.

In step S23, the playback pointer pp for reproduction is initialized to the head address of the recorded recording buffer, and the process proceeds to step S24. Step S24
Then, the state value st is incremented by 1 to step S2.
Go to 5 (st ++).

In step S25, it is determined whether or not the call is in progress. If the call is in progress (Yes), step S25.
26. If no call is being made (No), go to step S
Go to 31.

In step S26, the reception voice parameter output from the RF reception processing unit 5 is acquired, and in the next step S27, the filter state of the speech decoder 6a is exchanged (swapped) with the filter state of the save area 6c. The filter state for the received voice parameter is set, and in the next step S28, the voice decoder 6a performs voice decoding processing.

In the next step S29, the decoded output voice is copied or moved to the output buffer of the save area 6c, and in the next step S30, the filter state of the speech decoder 6a is exchanged with the filter state of the save area 6c ( Swap) to set the filter state for the recorded voice parameters.

In the next step S31, the recorded voice parameter is acquired from the position of the playback pointer pp in the memory 7, the playback pointer pp is updated in the next step S32, and the voice decoding process is performed in step S33. . In the next step S34, it is determined whether or not the call is in progress. When the call is in progress (Yes), the process proceeds to step S35, and when the call is not in progress (No), the process proceeds to step S37.

In step S35, the recording voice parameter is transmitted from the RF transmission processing unit 4 at an appropriate timing,
In step S36, both output voices of the reception output voice and the reproduction output voice are added to obtain an output voice, and then, step S3.
Go to 7.

In this embodiment, digital addition is performed by the adder 6d on the output side of the speech decoder 6, but two D / A converters are used as the D / A converter 9 in FIG. You may comprise so that each analog output from these two systems of D / A converters may be analog-added.

In step S37, it is determined whether or not there is a stop request from the user. If No, that is, there is no stop request, the process proceeds to step S38, and if Yes, that is, there is a stop request, the process proceeds to step S39. In step S38, it is determined whether or not the header value n_hd of the next frame is 0. If Yes, that is, n_hd = 0, the process proceeds to step S39, and if No, the reproduction routine is completed. In step S39, the state value st is set to 0, the end flag supplied to the control unit (for example, CPU) of the mobile phone is set, and this reproduction routine is ended.

According to such an embodiment of the present invention,
Not only can the voice parameters recorded in the memory 7 be decoded and played during standby, but during a call, both the voice parameters sent from the other party and the voice parameters recorded in the memory 7 can be decoded respectively. I can listen.

[0059]

As is apparent from the above description, according to the present invention, the output signal from the receiving means and / or the output signal from the compression encoding means for compressing and encoding the input audio signal is stored in the storage means. In addition, during the call, since the expansion decoding means performs expansion decoding on the output signal from the receiving means and the output signal from the storage means by the expansion decoding means to output a voice signal, The voice transmitted from the other party and the voice stored in the storage means can be heard at the same time.

In the storage means, one's own voice is stored in the form of high-efficiency-encoded voice parameters during standby, or the voice of oneself or the other party is in the form of high-efficiency-encoded voice parameters during a call. Can be memorized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a mobile phone to which a voice signal transmitting / receiving apparatus according to the present invention is applied.

FIG. 2 is a flowchart illustrating a recording operation in the mobile phone.

FIG. 3 is a diagram for explaining a recording mode of a voice parameter recorded in a voice recording memory.

FIG. 4 is a diagram for explaining a recording structure of a memory for voice recording.

FIG. 5 is a flowchart illustrating a reproducing operation in the mobile phone.

FIG. 6 is a conceptual block diagram for explaining a reproduction process of a speech decoder unit.

[Explanation of symbols]

 1 Microphone 2 A / D converter 3 Speech encoder section 4 RF transmission processing section 5 RF reception processing section 6 Speech decoder section 7 Memory 8 Recording / playback control section 9 D / A converter 10 Speaker

Claims (1)

[Claims] 1. A compression coding means for compressing and coding an input voice signal, a transmission means for performing a transmission process on an output signal from the compression coding means, and a reception means for performing a reception process on a received signal. Storage means for storing the output signal from the receiving means and / or the output signal from the compression encoding means, and decompressing and decoding the output signal from the receiving means and / or the output signal from the storage means. Decompression / decoding means for outputting an audio signal, and writing of a signal from the compression / encoding means to the storage means and / or a signal to the decompression / decoding means according to a transmitted / received signal and from the storage means. And a control means for controlling the read operation of the output signal and performing expansion decoding on the output signal from the receiving means and the output signal from the storage means by the expansion decoding means during transmission and reception. Audio signal transmitting and receiving apparatus, characterized by.