JPH03173229A - Bidirectional calling state detecting system - Google Patents
Bidirectional calling state detecting systemInfo
- Publication number
- JPH03173229A JPH03173229A JP31246989A JP31246989A JPH03173229A JP H03173229 A JPH03173229 A JP H03173229A JP 31246989 A JP31246989 A JP 31246989A JP 31246989 A JP31246989 A JP 31246989A JP H03173229 A JPH03173229 A JP H03173229A
- Authority
- JP
- Japan
- Prior art keywords
- wire
- echo
- correlation coefficient
- communication state
- way communication
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000002457 bidirectional effect Effects 0.000 title abstract 5
- 230000003044 adaptive effect Effects 0.000 claims abstract description 10
- 230000005540 biological transmission Effects 0.000 claims abstract description 7
- 238000004891 communication Methods 0.000 claims description 22
- 238000001514 detection method Methods 0.000 claims description 14
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 1
- 238000002592 echocardiography Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
Landscapes
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は双方向通話状態検出方式に関し、特に２線・４
線変換器の２線・４線変換に伴うエコーを除去する装置
の双方向通話状態検出方式に関する。[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a two-way communication state detection system, and in particular,
The present invention relates to a two-way communication state detection method for a device that removes echoes caused by two-wire/four-wire conversion of a line converter.
従来の双方向通話状態検出方式は、２線・４線変換器の
４線側入力信号と４線側出力信号との電力比を計算し、
この電力比を予め定められたしきい値と比較するだけで
双方向通話状態か否かを判定し、双方向通話状態時には
エコーを除去する装置の動作を規制するようになってい
た。The conventional two-way communication state detection method calculates the power ratio between the 4-wire side input signal and the 4-wire side output signal of the 2-wire/4-wire converter,
By simply comparing this power ratio with a predetermined threshold value, it is determined whether or not a two-way conversation is being made, and when the two-way conversation is in progress, the operation of the echo removing device is regulated.
上述した従来の双方向通話状態検出方式は、２線・４線
変換器の４線側入力信号と４線側出力信号との電力比を
計算する方法を取っているが、この方法が成立つために
は、４線側出力信号に含まれるエコー成分は極僅かで、
大部分は２線側の通話信号であることが必要である。し
かしながら実際の回線では、２線側の回線状態によって
エコー成分の電力が大きく変化するため、双方向通話状
態か否かを判定するための適切なしきい値を予め定める
ことは困難で、通常は、ある値以上の４線側出力信号に
ついては２線側の通話信号が大部分であると判断し、エ
コーを除去する装置の動作を規制するという割切りが必
要であるという問題点がある。The conventional two-way communication state detection method described above uses a method of calculating the power ratio between the 4-wire side input signal and the 4-wire side output signal of the 2-wire/4-wire converter. In order to
Most of the communication signals must be on the two-line side. However, in an actual line, the power of the echo component changes greatly depending on the line condition on the two-line side, so it is difficult to predetermine an appropriate threshold for determining whether or not a two-way communication is in progress. There is a problem in that it is necessary to judge that the majority of output signals on the 4-wire side that exceed a certain value are speech signals on the 2-wire side, and to regulate the operation of the echo removing device.
本発明の目的は、相関係数計算手段で２線・４線変換器
の４線側入力と４線側出力との相関係数を求め、この相
関係数を予め定められたしきい値と通話状態比較手段で
比較し、双方向通話状態か否かを判定することにより、
２線側の回線状態によってエコー成分の電力が大きくな
ってもエコーを除去する装置を動作させることが可能な
双方向通話状態検出方式を提供することにある。An object of the present invention is to obtain a correlation coefficient between a 4-wire side input and a 4-wire side output of a 2-wire/4-wire converter using a correlation coefficient calculation means, and to set this correlation coefficient to a predetermined threshold value. By comparing with the call state comparison means and determining whether or not the two-way call is in progress,
To provide a two-way communication state detection system capable of operating an echo removing device even if the power of an echo component increases depending on the line state on the second line side.
本発明の双方向通話状態検出方式は、２線・４線変換器
の２線−４線変換に伴うエコーを除去する装置の双方向
通話状態検出方式において、前記２線・４線変換器の４
線側入力と４線側出力との相関係数を求める相関係数計
算手段と、前記相関係数計算手段の出力を予め定められ
たしきい値と比較し双方向通話状態か否かを判定する通
話状態比較手段とを備える構成である。The two-way communication state detection method of the present invention is a two-way communication state detection method for a device that removes echo accompanying 2-wire to 4-wire conversion of a 2-wire to 4-wire converter. 4
Correlation coefficient calculating means for calculating a correlation coefficient between the line side input and the four line side output, and comparing the output of the correlation coefficient calculating means with a predetermined threshold value to determine whether or not a two-way communication state is established. This configuration also includes a call state comparison means.
本発明の双方向通話状態検出方式は、前記エコーを除去
する装置に設けられた４線側送信信号からエコー推定値
を出力する適応形フィルタに前記通話状態比較手段の出
力する双方向通話状態検出信号を入力し前記エコーの除
去状態を制御してもよい。The two-way communication state detection method of the present invention includes detecting the two-way communication state outputted by the communication state comparing means to an adaptive filter that outputs an estimated echo value from a 4-wire side transmission signal provided in the echo removing device. The echo removal state may be controlled by inputting a signal.
本発明の双方向通話状態検出方式は、前記相関係数計算
手段の入力情報として、前記４線側入力と４線側出力と
の電力をそれぞれ正規化した後に印加してもよい。In the two-way communication state detection method of the present invention, the power of the four-wire side input and the four-wire side output may be normalized and then applied as input information to the correlation coefficient calculation means.
次に、本発明の実施例について図面を参照して説明する
。Next, embodiments of the present invention will be described with reference to the drawings.
第１図は本発明の一実施例のブロック図である。FIG. 1 is a block diagram of one embodiment of the present invention.
２線・４線変換器１の４線側に接続し、４線側送信信号
と４線側受信信号との相関係数を求める相関係数計算回
路２は、計算結果である相関係数を比較回路３に出力す
る。比較回路３は、受信した相関係数を予め定められた
しきい値と比較し双方向通話状態か否かを判定し、双方
向通話状態であると判定すれば、このことをエコーキャ
ンセラ４に通知する。エコーキャンセラ４は、４線側送
信信号と４線側受信信号とからエコー推定値を出力する
適応形フィルタ５と、４線側受信信号からエコー推定値
を減算する減算回路６とを含んで構成される。A correlation coefficient calculating circuit 2 connected to the 4-wire side of the 2-wire/4-wire converter 1 and calculating the correlation coefficient between the 4-wire side transmitted signal and the 4-wire side received signal calculates the correlation coefficient that is the calculation result. Output to comparison circuit 3. The comparison circuit 3 compares the received correlation coefficient with a predetermined threshold value to determine whether or not a two-way conversation is in progress. Notice. The echo canceller 4 includes an adaptive filter 5 that outputs an estimated echo value from the 4-line side transmitted signal and the 4-line side received signal, and a subtraction circuit 6 that subtracts the echo estimated value from the 4-line side received signal. be done.
次に動作について説明する。Next, the operation will be explained.
４線側送信信号が強く４線側受信信号が弱いときには、
相関係数計算回路２の出力である相関係数が「１」に近
いため、この出力を受けた比較回路３は、予め定められ
たしきい値と比較し双方向通話状態ではないと判定し、
このことをエコーキャンセラ４に通知する。エコーキャ
ンセラ４は、双方向通話状態ではないとの通知を受ける
と、適応形フィルタ５に４線側送信信号と４線側受信信
号とを入力し、エコー推定値を出力させ、減算回路６に
入力し４線側受信信号からエコー推定値を減算させる。When the 4-wire side transmission signal is strong and the 4-wire side reception signal is weak,
Since the correlation coefficient output from the correlation coefficient calculation circuit 2 is close to "1", the comparison circuit 3 that receives this output compares it with a predetermined threshold and determines that there is no two-way communication state. ,
The echo canceller 4 is notified of this fact. When the echo canceller 4 receives the notification that the two-way conversation is not in progress, it inputs the 4-wire side transmission signal and the 4-wire side reception signal to the adaptive filter 5, outputs the estimated echo value, and sends the signal to the subtraction circuit 6. input and subtract the estimated echo value from the 4-wire side received signal.
次に双方向通話状態になると、相関係数計算回路２の出
力である相関係数が「０」に近くなる。Next, when a two-way conversation occurs, the correlation coefficient output from the correlation coefficient calculation circuit 2 becomes close to "0".
このとき、適応形フィルタ５には、共に強い４線側送信
信号と４線側受信信号とが入力される。At this time, the adaptive filter 5 receives the 4-line side transmission signal and the 4-line side received signal, both of which are strong.
したがって、そのままエコー推定値を出力させると誤っ
た値を出力してしまう可能性があるので、「０」に近い
相関係数の出力を受けた比較回路３は、予め定められた
しきい値と比較し双方向通話状態であると判定し、この
ことをエコーキャンセラ４に通知する。エコーキャンセ
ラ４は、双方向通話状態であるとの通知を受けると、適
応形フィルタ５の適応制御を停止し、固定型フィルタと
してエコー推定値を出力させ、減算回路６で４線側受信
信号から固定型フィルタとしてのエコー推定値を減算さ
せる。Therefore, if the estimated echo value is output as it is, there is a possibility that it will output an incorrect value, so the comparison circuit 3 that receives the output of the correlation coefficient close to "0" has a predetermined threshold value. By comparison, it is determined that a two-way conversation is in progress, and this is notified to the echo canceller 4. When the echo canceller 4 receives the notification that the two-way communication is in progress, it stops the adaptive control of the adaptive filter 5, outputs the estimated echo value as a fixed filter, and uses the subtraction circuit 6 to extract the estimated value from the received signal on the 4-wire side. Subtract the echo estimate as a fixed filter.
なお、相関係数計算回路２の入力である４線側送信信号
と４線側受信信号との値として、それぞれの電力を正規
化した後の値を相関係数計算回路２に印加することによ
り、相対的に比の値が大きいことによる誤差の発生等の
影響をさけている。In addition, by applying the values after normalizing the respective powers to the correlation coefficient calculation circuit 2 as the values of the 4-wire side transmission signal and the 4-wire side reception signal, which are input to the correlation coefficient calculation circuit 2, , the influence of errors caused by relatively large ratio values is avoided.
以上説明したように、本発明は、相関係数計算手段で２
線・４線変換器の４線側入力と４線側出力との相関係数
を求め、この相関係数を予め定められたしきい値と通話
状態比較手段で比較し、双方向通話状態か否かを判定す
ることにより、２線側の回線状態によってエコー成分の
電力が大きくなってもエコーを除去する装置を動作させ
ることが可能となる効果が有る。As explained above, the present invention provides correlation coefficient calculation means for
The correlation coefficient between the 4-wire side input and the 4-wire side output of the line/4-wire converter is calculated, and this correlation coefficient is compared with a predetermined threshold value using a call state comparing means to determine whether the call is in a two-way call state or not. By determining whether or not this is the case, it is possible to operate the device for removing the echo even if the power of the echo component increases depending on the line condition on the second line side.
１・・・・・・２線・４線変換器、２・・・・・・相関
係数計算回路、３・・・・・・比較回路、４・・・・・
・エコーキャンセラ、５・・・・・・適応形フィルタ、
６・・・・・・減算回路。1... 2-wire/4-wire converter, 2... Correlation coefficient calculation circuit, 3... Comparison circuit, 4...
・Echo canceller, 5...adaptive filter,
6... Subtraction circuit.
Claims (1)
除去する装置の双方向通話状態検出方式において、前記
２線・４線変換器の４線側入力と４線側出力との相関係
数を求める相関係数計算手段と、前記相関係数計算手段
の出力を予め定められたしきい値と比較し双方向通話状
態か否かを判定する通話状態比較手段とを備えることを
特徴とする双方向通話状態検出方式。 ２、前記エコーを除去する装置に設けられた４線側送信
信号からエコー推定値を出力する適応形フィルタに前記
通話状態比較手段の出力する双方向通話状態検出信号を
入力し前記エコーの除去状態を制御することを特徴とす
る請求項１記載の双方向通話状態検出方式。[Claims] In a two-way communication state detection method of a device for removing echo accompanying 2-wire/4-wire conversion of a 1-wire/2-wire/4-wire converter, the 4-wire side of the 2-wire/4-wire converter Correlation coefficient calculating means for calculating a correlation coefficient between the input and the output on the 4-wire side; and a telephone call for comparing the output of the correlation coefficient calculating means with a predetermined threshold value to determine whether or not a two-way communication state is established. A two-way call status detection method, comprising: status comparison means. 2. The two-way communication state detection signal output from the communication state comparison means is input to an adaptive filter that outputs an estimated echo value from the 4-wire side transmission signal provided in the echo removal device, and the echo removal state is determined. 2. The two-way communication state detection system according to claim 1, wherein the two-way communication state detection system controls:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31246989A JPH03173229A (en) | 1989-12-01 | 1989-12-01 | Bidirectional calling state detecting system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31246989A JPH03173229A (en) | 1989-12-01 | 1989-12-01 | Bidirectional calling state detecting system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03173229A true JPH03173229A (en) | 1991-07-26 |
Family
ID=18029577
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31246989A Pending JPH03173229A (en) | 1989-12-01 | 1989-12-01 | Bidirectional calling state detecting system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03173229A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0776118A3 (en) * | 1995-11-23 | 1997-06-25 | Alsthom Cge Alcatel | |
| JP2007274714A (en) * | 2007-05-07 | 2007-10-18 | Matsushita Electric Works Ltd | Echo canceller |
-
1989
- 1989-12-01 JP JP31246989A patent/JPH03173229A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0776118A3 (en) * | 1995-11-23 | 1997-06-25 | Alsthom Cge Alcatel | |
| US5799078A (en) * | 1995-11-23 | 1998-08-25 | Alcatel Alsthom Compagnie Generale D'electricite | Echo canceller |
| AU719761B2 (en) * | 1995-11-23 | 2000-05-18 | Alcatel | Echo cancellation method and circuit |
| JP2007274714A (en) * | 2007-05-07 | 2007-10-18 | Matsushita Electric Works Ltd | Echo canceller |
| JP4600423B2 (en) * | 2007-05-07 | 2010-12-15 | パナソニック電工株式会社 | Echo canceller |
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