close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JP2003008729

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2003008729
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
telephone and an echo cancellation method thereof.
[0002]
2. Description of the Related Art Conventionally, a telephone having a handsfree function is
equipped with an echo cancellation function. The echo cancellation function is a function for
preventing the reception voice of the other party of the calling party output from the
loudspeaker during the handsfree call from coming around the microphone and being
transmitted as an echo to the other party. With reference to FIG. 3, the conventional operation in
the telephone equipped with the echo cancellation function will be described.
[0003]
FIG. 3 is a flow chart showing the flow of conventional hands-free setting processing. In the
hands-free setting process of FIG. 3, when the telephone receives an external call, it outputs a
ringing tone (ringing tone) from the loudspeaker (step B1).
[0004]
15-04-2019
1
Next, the user (receiver) of the telephone set starts a call by a predetermined key operation in an
operation unit (not shown) or an operation such as picking up the receiver attached to the
telephone set (step B2). A normal call state is established (step B3).
[0005]
Here, when hands-free is to be performed (step B4; YES), a transition to hands-free mode is made
by a predetermined key operation from the user, that is, the echo cancellation function installed
in the telephone at this time is activated by the CPU. Be done.
Then, the echo cancellation function performs an adaptation process described later to remove
the echo (step B5 → step B6), and a hands-free call state becomes possible (step B7), and the
hands-free setting process is ended.
[0006]
However, conventionally, since the telephone set activates the echo cancellation function by a
predetermined key operation at the time of making a hands-free call, adaptive processing by the
echo cancellation function is performed. During this period (for example, about 1 to 2 seconds),
the level of the transmission signal to be transmitted to the other party is lowered to prevent the
echo that has entered the microphone from becoming the transmission signal to the other party.
There was a problem that I could not talk.
[0007]
The present invention is made to solve the above problems.
[0008]
SUMMARY OF THE INVENTION In order to solve the above problems, according to the present
invention, a receiving voice output from a receiving speaker wraps around a transmitting
microphone and transmits an echo component transmitted to a receiving side telephone. Echo
cancellation means for canceling from transmission voice, ringing tone generation means for
generating a ringing tone from the reception speaker in response to an incoming call, and call
start instructing means for instructing start of a call after the ringing tone is generated; The
telephone set includes control means for activating the echo canceling means when the ringing
tone is generated from the ringing tone generating means, and for performing an echo canceling
operation by the ringing tone that gets around the transmitting microphone. And
15-04-2019
2
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a telephone
set 100 to which the present invention is applied will be described in detail with reference to FIG.
1 and FIG.
First, the configuration will be described.
[0010]
FIG. 1 is a schematic view of the configuration of the telephone set 100. As shown in FIG.
In FIG. 1, the telephone set 100 includes a transmission / reception unit 1, an audio codec unit 2,
an echo canceller unit 3, a D / A converter 4, a loudspeaker 5, a microphone 6, and an A / D
converter 7.
Further, although not shown here, the telephone set 100 is provided with an operation unit or a
receiver, and starts a call by a predetermined key operation or an operation such as picking up
the receiver. That is, the operation unit or the handset has a function as call start instruction
means. Each part of the telephone 100 is uniformly controlled by a CPU (not shown). That is, the
CPU has a function as control means.
[0011]
The transmission / reception unit 1 includes a modem (MODEM: MOdulator / DEModulator), an
RF (Radio Frequency) unit, and an antenna 1a. Here, the digital transmission signal input from
the voice codec unit 2 is modulated by a modem, the modulated signal is frequency-converted by
the RF unit, amplified, and transmitted from the antenna 1a. Also, the digital reception signal
received via the antenna 1 a is amplified by the RF unit, frequency-converted, demodulated by
the modem, and output to the voice codec unit 2. When a call is received through the antenna 1a,
the CPU controls the sound source IC such as an FM sound source by the CPU, and the ringing
15-04-2019
3
voice signal generated from the sound source IC is used as the ringing tone (ringing tone) from
the loudspeaker 5 Output. Also, the ringing voice signal generated from the sound source IC here
is input to the adaptive filter 3 a of the echo canceller unit 3. That is, the sound source IC has a
function as ringing tone generating means.
[0012]
The voice codec unit 2 decodes the digital reception signal input from the transmission /
reception unit 1 and outputs it to the echo canceller unit 3 and encodes the digital reception
signal input from the echo canceller unit 3 to the transmission / reception unit 1 Output.
[0013]
The echo canceller unit 3 comprises an adaptive filter 3a and an arithmetic unit 3b, and outputs
the digital reception signal inputted from the voice codec unit 2 to the adaptive filter 3a and the
D / A converter 4.
[0014]
The echo canceller unit 3 also receives the digital speech signal inputted from the A / D
converter 7 and the digital speech signal passed through the adaptive filter 3a (predicted echo or
a ringing speech inputted from the sound source IC). The signal is compared with the signal by
the computing unit 3b to take a difference, and this difference is fed back to the adaptive filter
3a.
Then, the adaptive filter 3a controls (determines) the filter coefficients so as to minimize the
feedback difference (hereinafter, this process is referred to as adaptive process).
[0015]
Also, the echo canceller unit 3 generates an echo (for example, due to the voice of the other party
of the call output from the loudspeaker 5), which is contained in the digital transmission signal
input from the A / D converter 7 by this adaptive processing. The digital transmission signal from
which the sound picked up by the microphone has been removed is output to the audio codec
unit 2.
15-04-2019
4
That is, the echo canceller unit 3 has a function as an echo cancellation unit.
[0016]
The D / A converter 4 converts a digital reception signal input from the voice codec unit 2
through the echo canceller unit 3 into an analog voice signal and outputs the analog voice signal
to the loudspeaker 5.
[0017]
The loudspeaker 5 converts the analog voice signal inputted from the D / A converter 4 into the
reception voice of the other party and outputs it to the outside.
[0018]
The microphone 6 converts the user's transmission voice into an analog voice signal and outputs
the analog voice signal to the A / D converter 7.
[0019]
Further, the microphone 6 is an echo (a sound caused by the reception voice of the other party of
the calling party outputted from the loud speaker 5, ie, a sound outputted from the loud speaker
5, and this sound) which leads to the microphone 6 from the loud speaker 5. Echo sound etc.) is
also converted to an analog voice signal along with the transmission voice.
[0020]
The A / D converter 7 converts an analog voice signal (transmission voice including echo)
inputted from the microphone 6 into a digital transmission signal, and outputs it to the echo
canceller unit 3.
The A / D converter 7 converts the ringing tone (ringing tone) input from the microphone 6 into
a digital signal and outputs the digital signal to the echo canceller unit 3.
[0021]
15-04-2019
5
Next, the operation will be described.
FIG. 2 is a flowchart showing the flow of the echo canceller setting process performed by the
telephone set 100.
[0022]
In the echo canceller setting process shown in FIG. 2, when the telephone set 100 receives a call
through the antenna 1a in the transmitting and receiving unit 1, the CPU controls the sound
source IC and calls the calling voice signal generated from the sound source IC. A sound (ringing
tone) is output from the loudspeaker 5 (step A1).
At this time, the ringing tone (ringing tone) output from the loudspeaker 5 turns into the
microphone 6.
At this time, the call speech signal generated from the sound source IC is input to the adaptive
filter 3 a in the echo canceller unit 3.
[0023]
Then, the CPU of the telephone set 100 controls the echo canceller unit 3 to activate the echo
canceller unit 3 (step A2).
[0024]
The ringing tone input to the microphone 6 is converted into a digital signal by the A / D
converter 7 and output to the computing unit 3b.
Arithmetic unit 3b compares the digital signal input from A / D converter 7 with the call speech
signal output from adaptive filter 3a to obtain a difference, and feeds back the difference to
adaptive filter 3a. In this way, the echo canceller unit 3 performs adaptive processing.
15-04-2019
6
[0025]
Next, the user of the telephone set 100 starts a call by a predetermined key operation in the
operation unit (not shown) or an operation such as picking up the handset attached to the
telephone set 100 (step A3). (Step A4), and the echo canceller setting process ends.
[0026]
As described above, the telephone set 100 receives from the microphone 6 the ringing tone
output from the loudspeaker 5 under uniform control by the CPU (not shown), and activates the
echo canceller unit 3 using the ringing tone. And the adaptive processing in the echo canceller
unit 3 is immediately started.
[0027]
Therefore, since the echo canceller 3 is activated when the ringing tone (ringing tone) is output
from the loudspeaker 5, the transition to the handsfree mode can be smoothly made during a
call.
In addition, since it is not necessary to activate the echo canceller during a call, it is possible to
avoid a situation in which a call can not be made while the echo canceller unit 3 is activated and
subjected to adaptive processing, and to make a call smoothly.
[0028]
The present invention is not limited to the contents of the above embodiment, and can be
appropriately modified without departing from the scope of the present invention.
[0029]
According to the present invention, since the telephone set executes the echo cancellation
operation by the ringing tone which gets around the transmitting microphone, the situation that
the telephone can not be called when it shifts to the handsfree mode during the telephone call
can be realized. It can be avoided and calls can be made smoothly.
[0030]
Brief description of the drawings
15-04-2019
7
[0031]
1 is a block diagram showing a schematic configuration of a telephone.
[0032]
2 is a flowchart showing the flow of the echo canceller setting process of the present invention.
[0033]
3 is a flowchart showing a flow of hands-free setting process in the conventional telephone.
[0034]
Explanation of sign
[0035]
Reference Signs List 1 transceiver unit 1a antenna 2 voice codec unit 3 echo canceller unit 3a
adaptive filter 4 D / A converter 5 loud speaker 6 microphone 7 A / D converter 100 telephone
15-04-2019
8
Документ
Категория
Без категории
Просмотров
0
Размер файла
15 Кб
Теги
description, jp2003008729
1/--страниц
Пожаловаться на содержимое документа