JP3058064B2 - Digital radio telephone equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital radio telephone system, and more particularly to a telephone system of a cellular system or a personal handy phone (PHS) system. The present invention relates to a digital wireless telephone device that performs communication by switching and records and reproduces a call transmitted or received.

[0002]

2. Description of the Related Art Conventionally, a "digital telephone" disclosed in Japanese Patent Laid-Open Publication No. 1-109945 is known as a digital radio telephone apparatus for performing communication by switching between a plurality of different voice coding systems.

FIG. 2 is a block diagram showing an example of a conventional digital telephone device described in this publication. In FIG. 2, a digital telephone device has key telephones 1a and 1b having the same configuration.
And the base unit 2, and the key telephones 1a and 1b respectively have transmission / reception circuits 11a and 11b
Decoding circuits 12a and 12b, μ-law encoding / decoding circuit 13
a, 13b, selection circuits 14a, 14b, impedance circuits 15a, 15b, control circuits 16a, 16b, memories 17a, 17b, incoming call indicators 18a, 18b, A-law or μ-law selection button switches 19a, 19b, dial 2
0a, 20b, and decoding devices 21a, 21b for decoding a signal representing an encoding rule sent from an external device.

In the digital telephone device having this configuration, the selection circuits 14a and 14b select either the encoding / decoding circuits 12a and 12b or the μ-law encoding / decoding circuits 13a and 13b under the control of the control circuits 16a and 16b. I do.
The control circuits 16a, 16b store the selection results of the A-law or μ-law selection button switches 19a, 19b in the memories 17a, 1b.
7b, and at the time of transmission, data representing the storage result is added to the transmission data and transmitted. The control circuits 16a and 16b decode a signal indicating whether the signal sent from the external device is A-law or μ-law, and select circuits 14a and 1b corresponding to the result of the decoding.
4b.

As an answering machine having a plurality of different voice coding systems, an "answering machine" disclosed in Japanese Patent Laid-Open Publication No. Hei 5-236087 is known. This conventional telephone device has a recording / reproducing discriminating means,
The encoding method of the encoding means is switched according to the discrimination signal output from the recording / reproduction discrimination means.

Further, as a general method, when switching the encoding system, a code representing the encoding system is added to encoded data and stored, and upon reproduction, the code is detected and the encoding system is switched. ing.

[0007]

In the above-mentioned conventional digital radio telephone apparatus, the switching between different encoding systems is not performed a plurality of times during recording. At most one code data is increased in one recording data, and this code data does not greatly increase the storage capacity.

However, in a mobile telephone system such as a cellular system or a PHS system, a telephone call (communication) is performed by switching between a plurality of different voice coding systems, for example, by switching zones from a zone during a call to another zone. In some cases, storing the switching data of the audio encoding method makes it impossible to store the encoded audio signal for a long time. In other words, a large-capacity semiconductor storage device is required when recording and reproducing call voices, thus reducing the size of the device,
There was a drawback that weight reduction became difficult.

The present invention has been made in view of the above points,
Voice coded signal (transmitted call data or received call data)
By storing only the data, it is possible to reproduce the recorded contents by switching between different encoding methods, suppress an increase in the storage capacity, and eliminate the need for a large-capacity semiconductor storage device, thereby enabling downsizing and weight reduction. It is an object of the present invention to provide a digital radio telephone device.

[0010]

In order to achieve the above object, the invention according to claim 1 involves moving to a different zone.
A plurality of different speech coding schemes have, zones after movement
In a digital wireless telephone device that performs communication by switching to one voice coding method defined in, and that records or reproduces call voice, a transmission voice signal is transmitted by a plurality of different voice coding methods having different bit rates. Separate voice
After encoding, the first error correction corresponding to the audio encoding
Coding means for generating a transmission voice coded signal to which a positive code is added; and a plurality of transmission voice codes extracted from the coding means.
Transmission of one of the specified audio coding methods among the encoded signals
First selecting means for selecting an audio encoded signal;
Transmission audio of one audio encoding method extracted from the selection means
A wireless transmitting means for the coded signal radio transmission, a plurality of I different
Voice code in one of the
And the second corresponding to the audio coding method
Wirelessly receive a speech coded signal to which an error correction code has been added.
Wirelessly transmitted by wireless receiving means and wireless transmitting means
The transmitted voice coded signal and the radio reception
At least the received speech code
Storage means for storing the encoded signal and wireless reception means.
Line received received speech coded signal and read from storage means.
One of the output speech encoded signals is
Second selection means to be selected, and selection by the second selection means
Multiple different speech codes for the encoded speech signal
Decoding of error correction codes corresponding to each
After each run, each of several different speech coding schemes
Separates multiple audio decoded signals by performing audio decoding
Decoding means for outputting separately and sound read out from storage means
For a voice coded signal, a plurality of different voice coding
Decode the corresponding error correction code separately.
Input speech coded signal based on the obtained decoding result.
Output the audio coding system discrimination signal of the
If it is not possible to determine the audio coding method
Based on the discrimination signal of the previous speech coding method
A discrimination unit that outputs a discrimination signal of the audio coding method
From determination unit among the plurality of audio decoding signals from No. means
And a third selecting means for selecting one audio decoded signal based on the discrimination signal .

[0011]

[0012]

[0013]

The digital radio telephone apparatus of the present invention reads out and reproduces a voice coded signal, which is received voice data stored in a different voice coded system or business voice data for answering machine recording, and reproduces the voice coded signal. One of the decoding means corresponding to the coding method determined from the error correction code is selected and decoded.

Therefore, it is not necessary to add switching data to be selected from a plurality of encoding methods to the voice coded signal and record it, as is conventionally done, and the voice coded signal (transmission call data Alternatively, by storing only the received call data), the recorded contents are reproduced by switching between different encoding systems. As a result, an increase in storage capacity is suppressed.

[0016]

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a digital radio telephone according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a digital radio telephone apparatus according to the present invention. In FIG. 1, this example has a reception processing system, a transmission processing system, and a control processing system. The transmission processing system includes a transmitting / receiving antenna 21, an audio input unit 22 having a microphone and an amplifier, An A / D converter 23 for converting an analog audio signal from the section 22 into a digital audio signal;
3 has a voice coding unit 24a for compressing the digital voice signal output and converting it into a predetermined coded signal.

The audio encoder 24b converts the digital audio signal output from the A / D converter 23 into a predetermined encoded signal by performing compression different from that performed by the audio encoder 24a.
And an error correction code encoder 25a that adds an error correction code for correcting a code error occurring during transmission to the encoded audio signal output from the audio encoder 24a, and a voice encoder 24b. , For the encoded audio signal to be output,
An error correction code encoder 25b for adding an error correction code for correcting a code error generated at the time of transmission is provided.

Further, the error correction code encoders 25a, 2
5b, an encoding system switching unit 26 for selecting and transmitting one of the audio encoding signals from the encoding system selection signal, and converting the audio encoding signal output from the encoding system switching unit 26 into a predetermined transmission signal format. It has a transmission unit 28 that outputs the converted high-frequency signal, and a transmission / reception control unit 29 that switches transmission and reception of the transmission / reception antenna 21.

The reception processing system includes an antenna 21 for transmission and reception,
A reception unit 30 that converts a received signal input through the transmission / reception control unit 29 into a predetermined signal format, for example, an amplified and frequency-converted intermediate frequency signal into a speech coded signal, and a signal from the reception unit 30. A storage unit 31 that stores the encoded audio signal output from the encoding scheme switching unit 26.

This storage unit 31 is a semiconductor storage device 31a.
And an address control unit 31 for controlling write or read address designation for the semiconductor memory device 31a.
b.

Also, a switch unit 32 for selecting one of a voice coded signal from the receiving unit 30 and a voice coded signal from the storage unit 31 by a selection signal, and a switch added to the voice coded signal from the switch unit 32. An error correction code decoding unit 33a that corrects a transmission error of the voice coded signal based on the error correction code that has been transmitted, and a voice coding based on the error correction signal added to the voice coded signal from the switch unit 32. Error correction code decoder 3 for correcting errors in the signal transmission path
3b.

Further, a speech decoding section 34a for decoding the speech coded signal, which has been error-corrected by the error correction code decoding section 33a, into a digital speech signal;
b) a digital audio signal from the audio decoding units 34a and 34b according to an audio decoding unit 34b that decodes the audio coded signal subjected to error correction into a digital audio signal, and a coding system selection signal or an error correction code discrimination signal. And an encoding system switching unit 35 for selecting and outputting the selected one.

A D / A for converting a digital audio signal from the encoding system switching unit 35 into an analog signal and outputting the analog signal
It has a converter 37 and an audio output unit 38 that amplifies an analog audio signal from the D / A converter 37 with an amplifier and outputs the amplified signal from a speaker.

The control processing system has a system control unit 40 for transmitting a coding system selection signal to the coding system switching unit 26 and transmitting a selection signal to the switch unit 32 based on a user's operation instruction. doing. Also, the system control unit 4
0 at the time of reproduction according to the recording / reproduction control signal from 0.
The error correction code discriminating unit 41 that analyzes the voice coded signal from the CPU and outputs a coding method discrimination signal obtained by discriminating the voice coding method from the error correction code added to the voice coding to the coding method switching unit 35. Is provided. Furthermore, selecting a function, for example, an answering machine setting key for setting an answering machine, a transmitting memo key for instructing recording (memory) of transmitting voice, a receiving memo key for instructing recording of receiving voice, a recording / playback instruction key, The operation unit 42 includes a numeric keypad for inputting a number, a power key, and the like.

Next, the operation of this embodiment will be described.

The transmission voice is stored in the storage unit 31 (transmission memo).
In the normal transmission operation in the case where the voice signal is not transmitted, a voice signal transmitted by the user is input from a microphone (not shown) of the voice input unit 22, and the voice signal is amplified and then output to the A / D converter 23. The digital audio signal converted by the A / D converter 23 is input to the audio encoding units 24a and 24b, where the audio signals are subjected to different compression, and are respectively encoded by encoding methods having different bit rates. Is converted to

The speech coded signals output from the speech coding units 24a and 24b are output from the error correction coding
In 5a and 25b, an error correction code for correcting a code error occurring during transmission is added. One of the speech coded signals output from the error correction code coding units 25a and 25b is converted by the coding system switching unit 26 into a coding system selection signal transmitted from the system control unit 40 based on a user operation instruction. And outputs it to the transmission unit 28. Here, the voice coded signal is converted into a predetermined transmission signal format, and the high-frequency signal is wirelessly transmitted through the transmission / reception control unit 29 and the antenna 21.

Next, the receiving operation in the normal operation, that is,
In the storage of the received voice according to the instruction (reception memo) or the receiving operation when the received voice in the answering machine operation is not stored in the storage unit 31, the received voice is received through the antenna 21, the transmission / reception control unit 29, for example, from the cell base station. Is received by the receiving unit 30, where it is converted into a predetermined voice coded signal, and is input to the switch unit 32. The switch unit 32 selects one of the coded speech signal from the receiving unit 30 and the coded speech signal from the storage unit 31 with a selection signal from the system control unit 40.

The voice coded signal selected by the switch section 32 is input to error correction code decoding sections 33a and 33b, where the voice coded signal is transmitted based on the error correction code added to the voice coded signal. The error has been corrected,
The audio signals are decoded into digital audio signals by the audio decoding units 34a and 34b. The decoded signals from the audio decoding units 34a and 34b are selected and output by the encoding system switching unit 35. The decoded signal selected by the encoding system switching unit 35 is D /
The audio signal is converted into an analog audio signal by the A converter 37, amplified by the audio output unit 38, and output from the speaker.

Here, when the user presses the receiving memo key in the operation unit 42 in order to store the contents of the received call (receiving memo), the system control unit 40 performs the following control operation during the pressing. First, the address control unit 31 of the storage unit 31
b, a control signal for designating a read address is sent,
The semiconductor memory device 31a is set to the storage operation. The storage unit 31 stores the encoded audio signal output from the encoding scheme switching unit 26 and the receiving unit 30.

In this storage operation, the address control unit 31b
Designates the address of the semiconductor memory device 31a and stores it in the designated area. In other words, it is possible to store (receive memo), for example, the telephone number of the other party notified by the other party during the call. After this storage, when the recording / playback instruction key in the operation unit 42 is operated, the system control unit 4
0 sends a selection signal to the switch section 32 in response to this operation, and sends a coding scheme selection signal to the error correction code determination section 41. At the same time, a recording / playback control signal is sent to the storage unit 31.

The switch unit 32 is switched by a selection signal from the system control unit 40 so as to transmit the coded speech signal from the storage unit 31 to the error correction code decoding units 33a and 33b. Further, the storage unit 31 is set to a read state by a recording / reproduction control signal from the system control unit 40. Further, the error correction code discriminating unit 41 uses the coding method selection signal from the system control unit 40 to store the data in the storage unit 3.
1 is fetched and the error correction code is determined.

The error correction code discriminating section 41 performs a plurality of error correction code decodings, determines the input speech coding method based on the state of each error correction code decoded data, and switches the coding method. An encoding method determination signal is output to the unit 35. When the state of the transmission path is poor and it is difficult to determine each error correction code, the current (previous) error correction code stored in a memory or the like (not shown) in the system control unit 40 is used to determine the current error correction code. Is determined.

As described above, in this embodiment, when a telephone call (communication) is performed by switching a plurality of different audio coding systems by zone switching or the like, the coding system determined from the error correction code is used. Since the received voice coded signal is decoded, it is not necessary to store a code representing the coding method, and therefore, it is possible to suppress an increase in storage capacity.

The voice coded signal stored in the semiconductor storage device 31a of the storage unit 31 is read from the storage area designated by the address control unit 31b and supplied to the switch unit 32 and the error correction code discrimination unit 41, respectively. . Switch part 3
2 are first input to error correction code decoding units 33a and 33b, and then input to audio decoding units 34a and 34b to be decoded into digital audio signals.

These decoded signals are supplied to the encoding system switching section 35.
, Where one of the decoded signals selected by the coding scheme selection signal from the error correction code discriminating section 41 is D / A
After being supplied to the converter 37 and converted into an analog audio signal, the audio signal is amplified by the audio output unit 38 and output from the speaker.

Next, the answering machine operation will be described.

In this answering machine operation, when the answering machine setting key in the operation unit 42 is depressed, the system control unit 40 performs the answering machine operation, automatically sends a response message to the incoming call, and stores the message from the other party. Stored at 31. The subsequent operation is the same as in the reception memo for storing received calls memory unit 31. The operation of pressing the recording / playback instruction key to play back the stored (recorded) contents is also the same as the above-described operation of playing the received memo.

Next, a description will be given of a case in which a transmission memo is stored in which the contents of a transmission during communication are stored in the storage unit 31.

In this case, when the user transmits a message while pressing a transmission memo key (not shown) in the operation unit 42, the encoding system switching unit 2
The storage unit 31 stores the encoded voice signal, which is the transmitted voice data from No. 6. The playback operation of the stored (recorded) contents performed by pressing the recording / playback instruction key thereafter is the same as the playback operation of the received memo.

As described above, in this embodiment, the recorded contents can be reproduced by switching between different encoding systems depending on the audio encoded signal. That is, there is no need to add switching data to be selected from among a plurality of encoding methods to the audio encoded signal and record the same, as has been done conventionally, and increase the storage capacity of the storage unit 31 in the semiconductor storage device 31a. Can be suppressed.

In this embodiment, the transmission system coding system switching unit 26 is not provided, and the error correction coding coding unit 2
5a, 25b and the transmitting unit 28 are directly connected, and the audio encoding unit 2
4a, 24b and error correction code encoders 25a, 25b
One is set to the operation by the coding system selection signal from the system control unit 40, and the other is set to the non-operation so that one of the speech coded signals from the error correction code coding units 25a and 25b is set. You may make it output to the transmission part 28.

Similarly, in the receiving system, without providing the coding system switching unit 35, the audio decoding units 34a and 34b are directly connected to the D / A converter 37, and the coding system determination signal from the error correction code determination unit 41 is connected. Error correction code decoding sections 33a, 33
b and one of the audio decoding units 34a and 34b are set to the operation and the other is set to the non-operation, and one of the digital audio signals from the audio decoding units 34a and 34b is set to the D / A converter 37. May be output. In this case, current consumption can be reduced.

[0046]

As described above, according to the present invention ,
Since the speech coded signals stored in different speech coding schemes are decoded according to the coding scheme determined from the stored error correction codes, only the speech coded signal (transmitted speech data or received speech data) is output. By storing, the recorded contents are reproduced by switching between different encoding methods.
As a result, an increase in storage capacity can be suppressed, and a large-capacity semiconductor storage device is not required, so that reduction in size and weight can be achieved. Further, according to the present invention, the error correction code
If the judgment cannot be made,
Select the audio coding method of the received audio coding signal.
, There is a considerable probability of poor transmission path conditions.
Thus, a reproduced audio signal can be obtained.

[0047]

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a digital wireless telephone device of the present invention.

FIG. 2 is a block diagram showing an example of a conventional digital telephone device.

[Explanation of symbols]

 Reference Signs List 22 voice input sections 24a, 24b voice coding sections 25a, 25b error correction coding coding section 26 coding scheme switching section 28 transmission section 29 transmission / reception control section 30 reception section 31 storage section 31a semiconductor storage device 31b address control section 32 Switch unit 33a, 33b Error correction code decoding unit 34a, 34b Audio decoding unit 35 Encoding method switching unit 38 Audio output unit 40 System control unit 41 Error correction code discrimination unit 42 Operation unit

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04B 7/26 H04Q ⁷ /00-7/38 H04B 14/04

Claims (2)

(57) [Claims] 1. A method according to claim 1, wherein a plurality of different audio coding schemes are determined in a zone after the movement in accordance with the movement to a different zone .
In a digital radio telephone device for performing communication by switching to one voice encoding system and recording or reproducing speech voice, a plurality of different voice signals having different bit rates are transmitted.
After separately encoding the audio in each of the audio encoding methods,
Adding a first error correction code corresponding to the voice coding.
Encoding means for generating an encoded transmission speech signal, and a plurality of transmission speech encodings extracted from the encoding means.
Of the signals, the transmission voice of one of the specified voice coding systems
First selecting means for selecting an encoded signal, and the one audio code extracted from the first selecting means
Transmitting means for wirelessly transmitting a transmission voice coded signal of a coding scheme, and one voice code of the plurality of different voice coding schemes
Is encoded by the encoding method, and
Speech coded signal to which the corresponding second error correction code is added
Wireless receiving means for wirelessly receiving a signal, and the transmission voice code wirelessly transmitted by the wireless transmitting means.
And a reception signal wirelessly received by the wireless reception means.
At least the received speech encoding
Storage means for storing a signal, and received voice encoding wirelessly received by the wireless receiving means
Signal and the audio encoded signal read from the storage means.
A second selecting means for selecting one by an external instruction
And the audio encoded signal selected by the second selecting means.
On the other hand, each of the plurality of different speech coding schemes
After separately decoding the corresponding error correction code,
Audio decoding for each of a number of different audio coding schemes
Decoding that performs decoding and outputs multiple audio decoded signals separately
And means for speech coding signal read from said storage means,
Corresponding to each of the plurality of different audio coding schemes
The error correction code is separately decoded, and the obtained decoding result is obtained.
Of the input audio coded signal based on the
A separate signal is output, and the speech code is
If it is not possible to determine the
This speech coding method based on the discrimination signal of the voice coding method
Has a discriminating unit for outputting a determination signal of the formula, and a third selecting means for selecting one of the audio decoded signal based on the discrimination signal from the discriminating unit among the plurality of audio decoding signals from said decoding means A digital wireless telephone device characterized by the above-mentioned. 2. The method according to claim 1, wherein said first selecting means is replaced by said code.
Means for selecting from among the plurality of audio coding methods
Generates only speech-coded signals using a single speech coding method
Control means for controlling the encoding means so as to perform
In place of the third selection means, the decoding means
Corresponding to one audio coding method based on the discrimination signal from the
2. The digital radio telephone apparatus according to claim 1, wherein only the decoding operation is performed .