JPS63161762A - Echo canceller type two-way amplifier - Google Patents

Abstract

PURPOSE:To amplify a two-way sound signal without howling by previously storing the characteristic data of a line every line and reading out the respective characteristic data according to a line switching signal so as to carry out a digital process. CONSTITUTION:A titled device provides hybrid circuits 1 and 2 which divide the analog sound signal of a call into two-way signal, CODEC circuits 3 and 4 which convert the analog sound signal into a digital signal or convert the digital signal into the analog sound signal, a digital signal processor (DSP) 5 which amplifies the sound signal converted into the digital signal in the CODEC circuit 3 and 4 and executes the cancel of an echo which goes round to the hybrid circuits 1 and 2 and memories 6 and 10 which stores the characteristic data of the connected lines every line with a control input to the DSP 5. Even if the line is switched, the characteristic data of the line is read out so as to execute the digital process and the amplification of the two-way sound signal without howling can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention can be installed on a line where the voice becomes low due to line loss, and can be used without adjustment even when connected to lines with different characteristics such as outside lines and extension lines using a button telephone device etc. This invention relates to an echo canceller-type bidirectional amplifier for amplifying audio signals without howling.

2. Description of the Related Art A conventional echo canceller type bidirectional amplifier has a configuration as shown in FIG. That is, in Fig. 2, 1 and 2 are hybrid circuits that separate audio signals into two directions, such as converting 2 wires into 4 wires or 4 wires into 2 wires, and 3 and 4 are hybrid circuits that convert analog audio signals into digital signals. , or a codec circuit that converts a digital signal into an analog audio signal, and 5 amplifies the audio signal converted to a digital signal by the codec circuit 3 or 4 through digital processing, and
A digital signal processor (hereinafter referred to as D) cancels echoes coming from the hybrid circuit 1 or 2.
(abbreviated as SP), 6 is a memory for storing characteristic data of the line to be connected, and 7 is a line adaptive control circuit that performs control to check the line characteristic data (hereinafter referred to as line adaptive operation). 8 is a white noise oscillation circuit that generates white noise to be sent out during line adaptation,
XP1 to XP8 are a group of analog switches that turn ON/OFF or switch the communication path from line A to B or from line B to A during line adaptation operation.
9 is an activation switch for starting line adaptation operation.

Next, the operation of the apparatus having the above configuration will be explained.

Normal analog switch XPI, XP2. XP5.

XP6 is turned on, XP3. XP4. XP7. XP8 is O
FF L, a communication path from line A to line B has been established. When the start switch 9 is turned on, the line adaptation control circuit 7 starts the line adaptation operation and notifies the DSP 5 of this.The line adaptation control circuit 7 first controls the XP5.
Turn on XP6 (JFF, XP7゜P8, control C at the same time and start white noise oscillation circuit 8.) The white noise generated in white noise oscillation circuit 8 passes through XP7 and is routed from codec circuit 4 to DSP5 to codec circuit 3. →XP1→Exit to circuit A through hybrid circuit l.

At this time, due to the wraparound within the hybrid circuit 1,
P2 → Codec circuit 3 → DSP5 → Codec circuit 4
→White noise is returned via the route XP8.
The DSP 5 detects the frequency and level of this returned white noise and calculates characteristic data for canceling the echo.

Next, control of B returns to the original state, and this time it controls A, and XPI
, turn off XP2, turn off XP3. Turn on XP4.

Then, contrary to the above, the white noise is sent to the line B side, and the DSP 5 calculates characteristic data for canceling the echo in the same manner as above.

And the characteristic data of this line A side and line B side is Mesori 6
The two-line adaptation operation is completed and the control of A and C is returned to the original state. Since the memory 6 is backed up by a battery,
Once the adaptive operation is performed, the characteristic data can be read out at any time.The normal operation is as follows.

The audio signal input from line A is converted into a digital signal by the codec circuit 3, amplified by digital processing by the DSP 5, and sent to line B through the codec circuit 4 and the hybrid circuit 2. At this time, an echo returns to the DSP 5 due to looping within the hybrid circuit 2, but this echo is canceled by the characteristic data from the previous adaptation and no howling occurs. The same applies to voice input from line B.

In this way, even with the conventional echo canceller type bidirectional amplification device, it is possible to amplify bidirectional audio signals without causing howling by just adapting the device once.

Problems to be Solved by the Invention However, the conventional echo canceller-type bidirectional amplifier device can only adapt to a predetermined 1:10 line, so it has to adapt each time the line is switched. was there.

The present invention solves these conventional problems,
An object of the present invention is to provide an excellent echo canceller-type bidirectional amplifier capable of bidirectionally amplifying audio signals on one-to-many or many-to-many lines without a housing by simply adjusting the installation once. It is something.

Means for Solving the Problems In order to achieve the above object, the present invention provides a DSP line switching signal input and separate memories in which characteristic data for each line can be written and read based on the input. At the time of installation, the characteristic data of all lines is stored in each memory once, and when the line is switched, the data is immediately read out from the memory corresponding to the line, and the two-way audio signal is amplified without 1 ringing. According to the present invention, line characteristic data is stored in advance for each line, and each characteristic data is read out and digitally processed in response to a line switching signal. Therefore, regarding one-to-many or many-to-many lines, No.1
It is possible to amplify bidirectional audio signals without ringing, and it has the advantage that adaptation for this purpose does not have to be performed every time the switch is made, and only needs to be done once at the time of installation.

Embodiment FIG. 1 is a block diagram showing a schematic configuration of an echo canceller type bidirectional amplification device which is an embodiment of the present invention.

In Fig. 1, the same parts as Fig. 2 (1-5°, 7-9.
6.10 is a memory for storing characteristic data for each combination of lines A, O and C, and 11 is for controlling switching of lines (call paths). It is a line switching control switch, and is XP9. XPIO is an analog switch that switches lines (communication paths) using the control switch 11.

Next, the operation of the apparatus having the above configuration will be explained.

When the line changeover control switch 11 is OFF, analog switches XPI, XP2, XP5, XP6, XP9
is ONt,, XP3, XP4, XP7, XP8
, XPlo is 0FFt, A communication path from line A to line B is formed.

Then, when the start switch 9 is turned on, the line adaptive control circuit 7
starts the line adaptation operation and notifies the DSP 5 of this fact. The line adaptive control circuit 7 first controls XP5. XP
6 is turned off, XP7 and XP8 are turned on, and at the same time, C is controlled to start the white noise oscillation circuit 8.

The white noise generated in the white noise oscillation circuit 8 passes through the XP7, passes through the codec circuit 4→DSP5→codec circuit 3→XPI→hybrid circuit 1, and exits to the line A.

At this time, due to the wrap-around in the hybrid circuit 1,
2 → Codec circuit 3 → DSP5 → Codec circuit 4 →
White noise is returned via the route XP8. DP
85 detects the frequency and level of this returned white noise and calculates characteristic data for canceling the echo.

Next, control of B returns to the original state, and this time it controls A, and XPI
, XP2. OFF', XP3. Turn on XP4.

Then, contrary to the above, the white noise is sent to the line B side, and the DSP 5 calculates characteristic data for canceling the echo in the same manner as above.

Then, the characteristic data of the line middle side and the line B side are stored in the memory 6, and the line adaptation operation of the line middle side and the line B side is completed.
Return control of C.

On the other hand, when the line changeover control switch 11 is ON, the analog switch XP9 is OFF and XPIO is ON, forming a communication path from Line A to Line C.

Then, when the start switch 9 is turned on, the line adaptive control circuit 7
starts the line adaptation operation, and the DSP 5 calculates the characteristic data of the line middle C in the same way as the line middle B described above, and stores the data in the memory 10 this time. This memory 6
．． 10 is battery-backed up, so once the adaptive operation is performed, the characteristic data can be read out at any time.

Normal operation is as follows. Line switching control switch 11
When is OFF, that is, when a communication path is formed between the lines and the line B, the DPS 5 reads the characteristic data from the memory 6.

The audio signal input from line A is converted into a digital signal by the codec circuit 3, amplified by digital processing by the DSP 5, and sent to line B through the codec circuit 4 and the hybrid circuit 2.

At this time, an echo returns to the DSP 5 due to looping within the hybrid circuit 2, but this echo is canceled by the characteristic data in the memory 6 and no howling occurs. The same applies to the audio signal input from line B.

When the line changeover control switch 11 is ON, that is, when a communication path is formed from line middle to line C, the DSP 5
Characteristic data is read from the line Naka-B, and the line Naka-C also amplifies the voice signal without howling, in the same way as in the line Naka-B.

In this way, according to the above embodiment, the characteristic data of the line is stored in advance on the line side, and when the line is switched, the characteristic data suitable for the line is read out and digitally processed, so howling occurs no matter which line is connected. The present invention has the advantage that it is possible to amplify two-way audio signals without any noise, and there is no need to perform adaptation every time the switch is made, and only needs to be done once at the time of installation.

Also, in this embodiment, a one-to-two line was explained, but
It goes without saying that it is possible to support one-to-many or many-to-many lines by inputting control for multiple lines instead of the line switching control switch and increasing the number of connections.

Effects of the Invention As is clear from the above embodiments, the present invention has the following effects.

(1) The characteristic data of the connected line is stored in memory for each line, so even if the line is switched, the characteristic data of that line is read out and digitally processed to amplify bidirectional audio signals without howling. It can be carried out.

(2) If there is switching control input for multiple lines, line adaptation operations and storage of characteristic data in memory are performed in pairs for each connected line, so it can support one-to-many or many-to-many lines. It can be used in key telephone devices that switch between lines with different characteristics, such as external lines and internal lines.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram showing a schematic configuration of an echo canceller-type bidirectional amplifier according to an embodiment of the present invention, and FIG. 2 is a schematic configuration of a conventional echo canceller-type bidirectional amplifier. FIG. 1.2...Hybrid circuit, 3,4...Codec circuit, 5...Digital signal processor (DSP)
)-6, 10... Memory, 7... Line adaptive control circuit, 8... White noise oscillation circuit, 9... Adaptive start switch, 11... Line switching control switch, XP1~
XPIO...analog switch group.

Claims (1)

[Claims] A hybrid circuit that separates the analog audio signal of a call into two directions, a codec circuit that converts the analog audio signal into a digital signal, or a digital signal into an analog audio signal, and the audio converted into a digital signal by the codec circuit. A digital signal processor (hereinafter abbreviated as DSP) that amplifies the signal and cancels the echo that goes around the hybrid circuit, and a control input to the DSP stores characteristic data of the connected lines for each line. This echo canceller-type bidirectional amplifier device has a storage memory and is capable of amplifying audio signals without causing howling and without readjusting even if the connected line is switched.