JPH03254535A - Voice transmitter - Google Patents

Abstract

PURPOSE:To automate the control of start/stop of the bit steal mode by selecting a CODEC function depending on the bit steal state or not and controlling the switching with an external signal. CONSTITUTION:The start/stop of a bit steal circuit 12 is controlled by a bit steal mode switching circuit 13. When the mode switching circuit 13 does not start the bit steal circuit 12 depending on a command from an external control interface circuit 14, a voice CODEC 11 converts a digital signal from a digital interface circuit 15 into an analog signal as it is and outputs the result to an amplifier 18. When the bit steel circuit 12 is started, a bit to a bit steal in a digital signal from the said circuit 15 is extracted and outputted to a data communication interface circuit 21. Then the remaining digital signal is converted into an analog signal, which is outputted to the amplifier 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an audio transmission device having a bit steal function that enables data communication to be performed simultaneously with communication of analog signals such as voice or musical tones.

"Prior Art" Conventionally, broadcasting stations, etc. often have unmanned installations (e.g., transmitting stations, relay stations, etc.), so in order to remotely control these facilities, it is necessary to
P by using an analog line such as a general telephone line or a dedicated line
This has been done using B (push button) signal exchange and modems.

However, this method has problems such as the need to secure a dedicated telephone line or private line for this remote control, and because data is exchanged using analog signals, data cannot be transmitted at high communication speeds.

On the other hand, in digital lines, for example, INS Net 64 has an information channel of 64 kb/s, and SB-A
When using a DPCM (bandwidth division-adaptive differential PCM) type copic, it is possible to transmit analog signals with a band of up to 7Kl(z), making it suitable for transmitting high-quality audio at broadcasting stations. A portion of the digital signal (e.g. 8
kb/s or 16kb/s) for data transmission (bit stealing), and this data transmission channel can also be used to send and receive remote control data, so it is not necessary to secure a dedicated line for remote control. It has great advantages, such as being unnecessary, being able to perform data communications at higher speeds than before, and being able to send and receive voice at the same time as these data communications.

``Problem to be Solved by the Invention'' However, when bit stealing is used, distortion increases when quantizing an analog signal, resulting in an increase in distortion rate. Figure 11 shows the frequency vs. distortion characteristics of the SB-ADPCM codec. When using kb/s for data, mode 3 uses 48 kb/s for voice and 16 kb/s for voice.
An example of characteristics when s is used as data is shown. It can be seen that mode 2 is worse than mode l, and mode 3 is even worse.Mode 1 is preferable for use as a broadcast line at a broadcasting station, but mode 2 is better for remote control of broadcasting equipment. or 3. This selection must be set in advance on each other's terminals, so it is difficult to suddenly change the mode, and especially if the other party is unattended, the setting cannot be changed, and it is difficult to actually use it. Above, it is set from mode 2 to mode 3.

An object of the present invention is to provide an audio transmission device that automatically controls starting and stopping of the bit steal mode and significantly improves switching operability.

'Means for solving RM' This invention uses a part of the digital signal assigned to the codec for encoding the analog signal for data transmission,
A bit steal circuit that enables data communication at the same time as voice communication, a bit steal mode switching circuit that controls starting and stopping of the bit steal circuit, and a bit steal mode external control means for externally controlling the bit steal mode switching circuit. The most important feature is that it has the following.

The main feature of the invention according to claim 2 is that the bit steal mode switching circuit is controlled by the bit steal mode external control means when starting an outgoing call or an incoming call, and further includes a control means for starting the bit steal circuit. .

In the invention of claim 3, the data input/output processing means performs data communication by bit stealing when the bit steal communication means is activated and outputs data communication completion information when the data communication is completed; and the data input/output processing means. The main feature is that the apparatus further includes control means for controlling a bit steal mode switching circuit by the bit steal mode external restriction means and stopping the bit steal circuit when data communication completion information is input.

In the invention of claim 4, there is provided a partner terminal verification data storage means for storing verification data for determining whether the partner terminal is the same type of terminal, and a partner terminal verification data storage means that stores the verification data for determining whether the partner terminal is the same type of terminal, and the partner terminal verification data storage means Further, the control means extracts verification data for determining whether the terminals are of the same type, compares and verifies the verification data sent from the other terminal through the line, and performs the above-mentioned bit steal mode switching operation only when they match. The main feature is that

Embodiment FIG. 1 shows a first embodiment of the present invention. An audio codec 11 is one that mutually changes an analog signal and a digital signal of the SB-ADPCM system, for example, and performs data communication as well as voice communication. Bit steal circuit 1 that makes it possible
2.

The bit steal circuit 12 is controlled to start and stop by a bit steal mode switching circuit 13.

The bit steal mode switching circuit 13 is externally controlled by a bit steal mode external control interface circuit (interface circuit and terminal) 14. codec 1
The digital output side of 1 is a digital interface circuit (for example, 64 kb/s transmit/receive data and 8 kb/s
・16kb/s synchronization signal interface circuit and R3
422 terminal) 15, an analog input terminal 16 is connected to the analog input side through an amplifier 17, and an analog output side is connected to the analog output terminal 19 through an amplifier 18. A data communication interface circuit (interface circuit and terminal for input/output data and synchronization signals) 21 during bit stealing is connected to the bit stealing circuit 12 . The 111 source circuit 22 supplies operating power to each part.

According to instructions from the external control interface circuit 14, if the bit steal mode switching circuit 13 has not activated the bit steal circuit 12, the audio codec 11 converts the analog signal output from the amplifier 17 into a digital signal and outputs it as is. The signal is output to the digital interface circuit 15, and the digital signal from the digital interface circuit 15 is directly converted into an analog signal and output to the amplifier 18. When the bit steal circuit 12 is activated by the bit steal mode switching circuit 13, the amplification H
The output analog signal of 17 is converted into a digital signal, bit stealing is performed on the digital signal, and the data communication interface circuit 21
The data from the digital interface circuit 15 is inserted and output to the digital interface circuit 15.
The bit corresponding to the bit steal in the digital signal is extracted and output to the data communication interface circuit 21, and the remaining digital signal is converted to an analog signal and output to the amplifier 18.

A specific example of the audio codec 11, the bit steal circuit 12, and the bit steal mode switching circuit 13 is shown in FIG. 2. This example is a case where the audio codec 11 is applied to an SB-ADPCM codec, and the audio codec 11 is an SB-ADPCM encoding circuit. 23 and an SB-ADPCM decoding circuit 24, the data insertion circuit 25, 26 and the data branching circuit 27, which corresponds to the bit steal mode 2 or the bit steal mode 3 described in the description of the prior art, bits from 27 to 28. A steel circuit 12 is constructed.

The bit steal mode switching circuit 13 includes an insertion mode selection circuit 31 that switches and connects a path 29 that does not insert data and data insertion circuits 25 and 26 to the encoding circuit 23, a path 32 that does not branch data, and a data branch circuit 27. and 28
SB-ADPCM of the audio codec 11 in order to control these selection circuits 31 and 33 and perform optimal decoding adapted to each bit steal mode. The mode switching control circuit 34 controls the decoding circuit 24 to instruct the current bit steal mode. The bit steal mode external control interface control path 13 is connected to an external control terminal 35 for connecting an external control device and an external control interface circuit 36 for interfacing the external control device with the mode switching control circuit 34 of the bit steal mode switching circuit 13. configured.

The encoding operation operates as follows.

(2) Input audio in the 7 KHz band is converted into a 64 kb/s digital signal by the SB-ADPCM encoding circuit 23.

(2) In response to an instruction from an external control device connected to the external control terminal 35, the mode switching control circuit 34 is activated via the external control interface circuit 36, and the insertion mode selection circuit 31 performs the following three types of switching.

i) Mode 1: The 54 kb/s digital signal from the encoding circuit 23 is output as is for audio.

ii) Mode 2: Of the 64 kb/s digital signal of the encoding circuit 23, 8 kb/s is deleted and replaced with 8 kb/s external data input to the insertion circuit 25, resulting in 56 kb/s. It outputs 8 kb/s of audio and 8 kb/s of data.

ii) Mode 3: 16 kb/s of the 64 kb/s digital signal of the encoding circuit 23 is deleted and replaced with 16 kb/s external data input to the insertion circuit 26, resulting in 48 kb/s audio. , outputs data at 16 kb/s.

Note that the 64 kb/s digital signal in each mode is output to the digital interface circuit 15 through a common output terminal.

Next, the decoding operation will be explained.

■ In response to an instruction from an external control device connected to the external control terminal 25, the mode switching control circuit 36 is activated via the external control interface circuit 36, and the branch mode selection circuit 33 is activated.
Switch between the following three types.

i) Mode I: The 64 kb/s digital signal input from the digital interface circuit 15 is directly input to the LSB ADPCM decoding circuit 24 and output as audio in the 7 KHz band. On the other hand, the mode switching control circuit 34 instructs the SB-ADPC M decoding circuit 24 to be in mode 1 and performs normal decoding, thereby making it possible to perform optimal decoding adapted to mode 1.

Mode 2: Out of the input 64 kb/s digital signal, 8 kb/s external data is branched out at the branch circuit 27, and the remaining 56 kb/s is input as an audio signal to the SB-ADPCM decoding circuit 24. and outputs it as audio in the 7KHz band. On the other hand, the mode switching control circuit 34 instructs the SB-ADPCM decoding circuit 24 to be in mode 2, sets the decoding circuit to the same state as the decoding in the conventional bit steal to 8kb, and adapts to mode 2. perform optimal decoding.

Mode 3: Out of the input 64 kb/s digital signal, 16 kb/s external data is branched out at the branch circuit 28, and the remaining 48 kb/s is sent to the SB-ADPCM decoding circuit 24 as an audio signal. It is input and output as upper band audio to 7. On the other hand, since the mode switching control circuit 34 instructs the SB ADPCM decoding circuit 24 to be in mode 3, optimal decoding adapted to mode 3 can be performed.

FIG. 3 shows a second embodiment of the invention, in which parts corresponding to those in FIG. 1 are given the same reference numerals. A data input/output processing circuit 37 is connected to the data communication interface circuit 21 for outputting and processing data transmitted and received using a bit steal function.

Analog input terminal 16 and analog output terminal 19 are connected to microphone 39 and speaker 41 through audio input/output amplification circuit 38, respectively. A driver receiver 42 for the digital line is connected to a layer 2 control circuit 43,
Bit steal mode external control interface circuit 14
A layer 3 man-machine control circuit 45 having a bit steal mode control circuit 44 is connected to the layer 2 control circuit 43, and a dial key 46 and a display 47 are connected to the layer 3 man-machine control circuit 45. . The channel selector 48 is connected to the layer 2 control circuit 43, as well as to the codec/speech/tone circuit 49 and the digital interface circuit 15. A handset sounder 51 is connected to the codec/talk/tone circuit 49. FIG. 4 is a flowchart showing the operation of this second embodiment, and the operation of this second embodiment will be explained below using this flowchart.

Activation of outgoing or incoming calls for voice signals (STEPI)
), the bit steal mode control circuit 44 of the layer 3/man-machine control circuit 45 is activated, controls the bit steal mode switching circuit 13 via the bit steal mode external control interface circuit 14, and switches the audio codec 1
1 bit steal circuit 12 is activated (STEP 2)
On the other hand, the information channel (64 kb/S) of the line is sent to the audio codec 11 via the channel selector 48 and the digital interface circuit 15.
It is connected to the analog input amplifier 17, the analog output amplifier 18, the analog input terminal 16, and the analog output terminal 19, and then the audio input/output amplifier circuit 38 enables a telephone call. The input/output processing circuit 37 enables data communication (ST
EP3).

This data input/output processing circuit 37 transmits and receives data at the same time as the voice call (STEP 4).As explained above, in this second embodiment, when there is an outgoing or incoming call, both terminals automatically enter the bit steal mode. Therefore, it has excellent operability. Furthermore, by making the activation operation on the receiving side an automatic response, it is always possible to send and receive data (remote control wj) at the same time as voice communication even if the other party is unattended.

FIG. 5 shows a third embodiment of the present invention, in which a bit steal mode control circuit 52 is provided in contrast to the second embodiment shown in FIG.
When the data communication completion information is input from 7, the bit steal mode external control interface circuit 14 is controlled. FIG. 6 is a flowchart showing the operation of the third embodiment, and the operation of the third embodiment will be explained below using this flowchart.

The operation from 5TEPI to 5TEP4 is as shown in 2 of Fig. 4.
The operation is the same as that of the embodiment. When the data communication carried out in 5TEP4 is completed (STEP5), data communication completion information is output from the data input/output processing circuit 37 to the bit steal mode control circuit 52, and the control circuit 52 passes through the bit steal mode external control interface circuit 14. Controls the bit steal mode switching circuit 13 and stops the bit steal circuit 12 of the audio codec 11 (S
TEP 6) Then, the audio codec 11 allocates all the information channels (64 kb/s) of the line to audio encoding, so that quantization distortion is reduced and high-quality audio can be communicated (STEP 7).

In this way, in the third embodiment, data communication (remote control)
When the process is completed, bit stealing is automatically stopped and all information channels (64kb/s) of the line are allocated to audio encoding, which significantly reduces quantization distortion and enables high-quality voice calls. There is no need to switch the mode of the terminal, and it is extremely easy to use.

FIG. 7 shows a fourth embodiment of the present invention, in which verification data (sub-address, user information, communication class, etc.) for determining whether the partner terminal is the same type of terminal in the third embodiment is stored. Partner terminal verification data storage circuit 5
3 is connected to layer 3/man-machine control circuit 45.

FIG. 8 is a flowchart showing the operation of this fourth embodiment, and the operation of this fourth embodiment will be explained below using this flowchart.

When an outgoing call (STEP 4) or an incoming call (STEPlo) is activated, and there is a response from the other party's terminal (STEP 2) or an incoming call response (STEP 11), the layer 3 man-machine control circuit 45 retrieves the verification data from the other party's terminal verification data storage circuit 53. (subaddress, user user information, communication class, etc.) and compare it with the verification data sent from the other party's terminal through the line. Only if they match (STEP 3.12) 5TEP4 to 5TEP9 and 5TEP13 to 5TEP in FIG. 8, which perform the operation of the third embodiment of the present invention.
The operation up to 1B is from 5TEP2 to 5TE in Figure 6.
The operation is the same as that up to P7. In this way, in the fourth embodiment, the automatic switching of starting and stopping Focus Steel is performed after comparing the terminals, so when connecting with a terminal that does not have Bit Steal automatic switching control function, it is possible to switch to Bit Steal mode. Therefore, there is no need to be aware of the other party's terminal and switch the mode of the terminal each time, resulting in extremely high operability.

FIG. 9 shows a fourth alternative embodiment of the present invention, which is an example in which the present invention is applied to broadcasting equipment. A broadcasting equipment remote control circuit 54 for remotely controlling broadcasting equipment is used instead of the data input/output processing unit B37, and the audio input/output amplification circuit 3
Broadcasting 81RN55 is used instead of 8, and a partner terminal subaddress storage circuit 56 that stores the partner subaddress as verification data is used instead of the partner terminal verification data storage circuit 53. As audio codec 11, 7K
) SB-ADPCM that can transmit high-quality audio in the tz band
method is used. FIG. 10 is a flowchart showing the operation of the fourth alternative embodiment shown in FIG. 9, and the operation of this fourth alternative embodiment will be explained below using this flowchart.

When an outgoing call (STEPI) or an incoming call (STEPIO) is activated and there is a response from the other party's terminal (STEP 2) or an incoming call response (STEP II), the layer 3 man-machine control circuit 45 stores the subaddress of the other party's terminal from the other party's terminal subaddress storage circuit 56. is extracted and compared with the subaddress sent from the other party's terminal over the line (STE
P3 or 5TEP 12) Only when there is a match, the bit steal mode control circuit 44 of the layer 3 man-machine control diagram IIB45 is activated and controls the bit steal mode switching circuit 13 via the bit steal mode external control interface circuit 14. , start the focus steal circuit 12 of the audio codec 11 (STEP 4 or 5T)
EP13). On the other hand, the line information channel (64kb/s
) is connected to the audio codec 11 via the channel selector 48 and the digital interface circuit 15, and via the analog input amplifier 17, analog output amplifier 18, analog input terminal 16, and analog output terminal 19, the broadcast equipment 55 outputs 7KHz audio. In addition to enabling communication,
Through the data communication interface circuit 21, the broadcasting equipment remote control circuit 54 enables remote control such as channel switching and level adjustment of the broadcasting equipment 55 (STEP 5 or 5TEP14). (STEP 6 or 5 TEP)
15).

When the remote control of the broadcast equipment 55 is completed at the same time as the 7KHz audio communication (STEP 7 or 5TEP 16), data communication completion information is output from the broadcast equipment remote control port 154 to the bit steal mode control circuit 52, and the bit steal mode external control interface The bit steal mode switching circuit 13 is controlled via the circuit 14 to stop the focus steal circuit 12 of the audio codec 11 (STEP
8 or 5TEP17), then audio codec 11
allocates the entire information channel (64kb/s) of the line to audio encoding, reducing quantization distortion and enabling higher quality 7 to 1 (Z) audio communication (STEP 9 or 5).
TEP18) In this way, in this embodiment, when remote control of the broadcasting equipment is completed, bit stealing is automatically stopped and the entire information channel (64 kb/s) of the line is allocated to audio encoding to eliminate quantization distortion. This significantly reduces the frequency and enables higher-quality 7KHz voice communication, which eliminates the need to switch the mode of each terminal one by one, resulting in extremely high operability. In particular, since it is normal for broadcasting equipment to be set up first, the broadcasting equipment must be set up by remote control before the start of broadcasting, and the information channel (64kb/ s) is allotted to audio encoding, allowing high-quality 7KHz audio communication, which is extremely convenient. In addition, the 5TEP of the called side
By performing the operation II as an automatic response, the receiving side may be unmanned, and the receiving side is very effective in broadcasting stations where there are many unmanned facilities (transmitting stations, relay stations, etc.).

"Effects of the Invention" As explained above, in this invention, the codec can be switched between the bit steal state and the non-bit steal state, and this switching can be controlled by an external signal, so the bit steal mode The start and stop of the bit steal mode can be automatically controlled, and the operability of bit steal mode switching can be significantly improved.

This invention is particularly effective for remotely controlling unmanned equipment (e.g., transmitting stations, relay stations, etc.) at broadcasting stations. After the broadcast ends, the information channel is assigned to all audio encoding, allowing high-quality audio communication.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of this invention, FIG. 2 is a block diagram showing a specific example of the main part thereof, and FIG. 3 is a block diagram showing a second embodiment of this invention. 4 is a flowchart showing the operation of the second embodiment of the present invention;
FIG. 6 is a block diagram showing the third embodiment of the invention, FIG. 6 is a flowchart showing the operation of the third embodiment of the invention, and FIG. 7 is a block diagram showing the fourth embodiment of the invention.
FIG. 8 is a flowchart showing the operation of the fourth embodiment of the invention, FIG. 9 is a block diagram showing the fourth other embodiment of the invention, and FIG. 10 is a fourth other embodiment of the invention. A flowchart showing the operation of an example, FIG. 11 is SB-ADPCM
FIG. 3 is a diagram showing the frequency versus distortion characteristics of the codec of the system. )t72nd

Claims (4)

[Claims] (1) In an audio transmission device that has a built-in codec that mutually converts analog signals such as voices or musical tones and digital signals, and transmits the analog signals to the communication partner via a digital line, the analog signals are encoded using the codec. a bit steal circuit that uses a part of the digital signal allocated to the digital signal for data transmission to enable data communication at the same time as voice communication; a bit steal mode switching circuit that controls starting and stopping of the bit steal circuit; An audio transmission device comprising: bit steal mode external control means for externally controlling a steal mode switching circuit. (2) The audio transmission device according to claim 1, further comprising control means for controlling the bit steal mode switching circuit by the bit steal mode external control means and activating the bit steal circuit when starting an outgoing call or an incoming call. A voice transmission device characterized by: (3) In the audio transmission device according to claim 1 or 2, data input/output processing performs data communication by bit steal when the bit steal circuit is activated, and outputs data communication completion information when the data communication is completed. and control means for controlling the bit steal mode switching circuit by the bit steal mode external control means to stop the bit steal circuit when data communication completion information is input from the data input/output processing means. audio transmission equipment. (4) In the audio transmission device according to claim 2 or 3, a partner terminal verification data storage means for storing verification data for determining whether or not the partner terminal is the same type of terminal; The verification data for determining whether the partner terminal is the same type of terminal is retrieved from the terminal verification data storage means, and compared with the verification data sent from the partner terminal through the line. 4. A voice transmission device comprising means for enabling the control means according to 2 or 3.