JPH0555961A - Loud-speaker simultaneous speech system using frequency division - Google Patents
Loud-speaker simultaneous speech system using frequency divisionInfo
- Publication number
- JPH0555961A JPH0555961A JP21545991A JP21545991A JPH0555961A JP H0555961 A JPH0555961 A JP H0555961A JP 21545991 A JP21545991 A JP 21545991A JP 21545991 A JP21545991 A JP 21545991A JP H0555961 A JPH0555961 A JP H0555961A
- Authority
- JP
- Japan
- Prior art keywords
- upstream
- band
- voice signal
- low
- filter
- 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
Landscapes
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は周波数分割を用いた拡声
同時通話方式に係わり、特に上り、下り音声信号の低域
はエコーキャンセラ方式、高域は発信、着信等の呼発生
要因により定められた要素で相補的に対応して通過、阻
止させるよう周波数分割する方式で通話帯域を定める周
波数分割を用いた拡声同時通話方式に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker simultaneous call system using frequency division, and in particular, low frequencies of upstream and downstream voice signals are determined by an echo canceller system, and high frequencies are determined by call generation factors such as outgoing and incoming calls. The present invention relates to a loudspeaker simultaneous call system using frequency division in which a call band is determined by a method of frequency division so as to complementarily pass and block corresponding to each other.
【0002】[0002]
【従来技術および発明が解決すべき課題】通常、エコー
キャンセラを用いた拡声同時通話方式を適用した拡声用
同時通話装置TE2は図7に示すようにマイク21、上
りA/D変換器22、上りD/A変換器23、下りA/
D変換器24、スピーカ25及びCPU26で構成さ
れ、CPU26は上りA/D変換器22と下りA/D変
換器24から入力されるデジタル信号を参照し疑似エコ
ーを演算するエコーキヤンセル演算プログラムを内蔵す
る。2. Description of the Related Art Generally, a simultaneous voice-over communication device TE 2 to which a voice-up simultaneous communication system using an echo canceller is applied has a microphone 21, an upstream A / D converter 22, as shown in FIG. Upstream D / A converter 23, downstream A / A
It is composed of a D converter 24, a speaker 25 and a CPU 26, and the CPU 26 has a built-in echo cancel cell calculation program for calculating a pseudo echo by referring to digital signals input from the upstream A / D converter 22 and the downstream A / D converter 24. To do.
【0003】マイク21の出力側は上りA/D変換器2
2を介してCPU26の制御入力側に接続され、下り伝
送路L4が接続された端子T4はスピーカ25と下りA/
D変換器24を介してCPU26の制御入力側に接続さ
れ、CPU26の制御出力側は上りD/A変換器23を
介して上り伝送路L3が接続された端子T3に接続され
る。上記構成の拡声用同時通話装置TE2で通話すると
マイク21で生成された上り音声信号FSと下り伝送路
L4が接続された端子T4から入力される下り音声信号F
Rはそれぞれ、上りA/D変換器22とA/D変換器2
4でデジタル信号に変換され、CPU26に内蔵された
エコーキヤンセル演算プログラムにより上り、下り音声
信号の帯域全域の疑似エコーが演算され、演算された疑
似エコーが除去された上り音声信号FSが端子T3から
上り伝送路L3へ送出される。The output side of the microphone 21 is an upstream A / D converter 2
The terminal T 4 connected to the control input side of the CPU 26 via the downlink transmission line L 4 is connected to the speaker 25 and the downlink A /
It is connected to the control input side of the CPU 26 via the D converter 24, and the control output side of the CPU 26 is connected to the terminal T 3 connected to the upstream transmission line L 3 via the upstream D / A converter 23. When a call is made using the above-described simultaneous voice communication device TE 2 , the upstream voice signal FS generated by the microphone 21 and the downstream voice signal F input from the terminal T 4 to which the downstream transmission line L 4 is connected.
R is the upstream A / D converter 22 and the A / D converter 2 respectively.
4 is converted into a digital signal, a pseudo echo in the entire band of the upstream and downstream voice signals is calculated by the echo cancel operation program stored in the CPU 26, and the upstream voice signal FS from which the calculated pseudo echo is removed is the terminal T 3 To the upstream transmission line L 3 .
【0004】このようにして疑似エコーが除去された上
り音声信号FSにより網を介して拡声同時通話を行ない
ハウリングを防止している。エコーキヤンセル方式によ
るハウリングを防止する上記構成の拡声用同時通話装置
TE2では、周囲環境の変動や、双方の通話者が同時に
送話を行なうダブルトーク時において、音質の劣化、音
量の低下等を惹起し、特殊な条件下でしかハウリングを
防止できなかつた。これは、エコーキヤンセル方式で取
扱う周波数が高いとき周囲環境の影響を受けやすくなる
ためである。In this way, the up-speech signal FS from which the pseudo echo has been removed is used to carry out a loud voice simultaneous call through the network to prevent howling. In the loudspeaker simultaneous communication device TE 2 having the above-mentioned configuration which prevents howling by the echo cancel method, deterioration of the sound quality, a decrease in the volume, etc. are caused by the fluctuation of the surrounding environment and the double talk in which both parties simultaneously speak. It caused and howling could only be prevented under special conditions. This is because when the frequency handled by the echo cancel method is high, the environment is likely to be affected.
【0005】[0005]
【発明の目的】本発明は上述した難点に鑑みなされたも
ので、マイクから出力される上り音声信号とスピーカへ
入力される下り音声信号を低域と高域に分割し、上り音
声信号の低域は下り音声信号の低域を参照して作成され
た疑似エコーを減算した上り音声信号で通話し、上り、
下り音声信号の高域は発信、着信等の呼発生要因により
定められた要素で相補的に対応して通過、阻止して通話
する周波数分割を用いた方式により音声信号の全域に亘
つて、周囲環境の変動や、双方の通話者が同時に送話を
行なうダブルトーク時に安定した動作が図れる周波数分
割を用いた拡声同時通話方式を提供することを目的とす
る。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and divides an upstream audio signal output from a microphone and a downstream audio signal input to a speaker into a low band and a high band to reduce the upstream voice signal. The area is the upstream voice signal that is obtained by subtracting the pseudo echo created by referring to the low frequency band of the downstream voice signal,
The high frequency band of the downstream voice signal is complemented by the elements determined by the call generation factors such as outgoing and incoming calls, and it passes through and blocks the call in a complementary manner. It is an object of the present invention to provide a loudspeaker simultaneous call system using frequency division, which can achieve stable operation during environmental changes and double talk in which both parties simultaneously transmit.
【0006】[0006]
【課題を解決するための手段】本発明の周波数分割を用
いた拡声同時通話方式は、マイクから出力される上り音
声信号とスピーカへ入力される下り音声信号を低域と高
域に分割し、上り音声信号の低域は下り音声信号の低域
を参照して作成された疑似エコーを減算した上り音声信
号で通話し、上り、下り音声信号の高域は発信、着信等
の呼発生要因により定められた要素で相補的に対応して
通過、阻止させる方式である。A loudspeaker simultaneous call system using frequency division of the present invention divides an upstream voice signal output from a microphone and a downstream voice signal input to a speaker into a low band and a high band, The low frequency band of the upstream voice signal is used for the call with the upstream voice signal obtained by subtracting the pseudo echo created by referring to the low frequency band of the downlink voice signal. This is a method of passing and blocking correspondingly in a complementary manner with predetermined elements.
【0007】[0007]
【作用】マイクから出力される上り音声信号とスピーカ
へ入力される下り音声信号を低域と高域に分割し、上り
音声信号の低域は下り音声信号の低域を参照して作成さ
れた疑似エコーを減算した上り音声信号で通話し、上
り、下り音声信号の高域は発信、着信等の呼発生要因に
より定められた要素で相補的に対応して通過、阻止させ
るよう周波数分割した上り、下り音声信号で通話するこ
とを特徴とする周波数分割を用いた拡声同時通話方式。[Operation] The upstream audio signal output from the microphone and the downstream audio signal input to the speaker are divided into a low frequency band and a high frequency band, and the low frequency band of the upstream audio signal is created by referring to the low frequency band of the downstream audio signal. A call is made with an upstream voice signal from which pseudo echo has been subtracted, and the high frequencies of the upstream and downstream voice signals are frequency-divided upstream so as to pass and block in a complementary manner with elements determined by call generation factors such as outgoing and incoming calls. , A simultaneous voice call system using frequency division, which is characterized in that a call is made using a downlink voice signal.
【0008】これにより、エコーキヤンセル機能を改善
し、音声信号の全域に亘つて、周囲環境の変動や、双方
の通話者が同時に送話を行なうダブルトーク時に安定し
た動作が図れる。As a result, the echo cancel function is improved, and stable operation can be achieved during a double talk in which both parties talk at the same time by changing the surrounding environment over the entire range of the voice signal.
【0009】[0009]
【実施例】以下、本発明による周波数分割を用いた拡声
同時通話方式を適用した拡声用同時通話装置TE1の一
実施例を図1〜図6に従って詳述する。本発明による周
波数分割を用いた拡声同時通話方式が適用される拡声用
同時通話装置TE1は図1に示すように、マイク1、上
り発側低域エリミイネエイトフィルタ2、上り着側低域
エリミイネエイトフィルタ3、上りローパスフィルタ
4、上りA/D変換器5、CPU19の制御をうけるD
/A変換器6並びに上りアナログスイッチ7、加算器
8、下り発側バンドパスフィルタ9、下り着側バンドパ
スフィルタ10、下りローパスフィルタ11、下りA/
D変換器12、下りアナログスイッチ13、スピーカ1
4、エコーキヤンセル演算プログラムが内蔵されたCP
U19で構成する。マイク1の出力側は上り発側低域エ
リミイネエイトフィルタ2、上り着側低域エリミイネエ
イトフィルタ3及び上りローパスフィルタ4の入力側と
接続され、上り発側低域エリミイネエイトフィルタ2、
上り着側低域エリミイネエイトフィルタ3の出力側はC
PU19の制御をうける上りアナログスイッチ7の常
閉、常開接点にそれぞれ接続される。また、上りアナロ
グスイッチ7の可動接点はCPU19の制御をうけるD
/A変換器6の出力側が接続された加算器8を介して伝
送路L1が接続されたに端子T1に接続される。更に、上
りローパスフィルタ4の出力側は上りA/D変換器5を
介してCPU19と接続される。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a simultaneous voice communication system TE 1 to which the simultaneous voice communication system using frequency division according to the present invention is applied will be described in detail below with reference to FIGS. As shown in FIG. 1, a loudspeaker simultaneous speech communication device TE 1 to which a loudspeaker simultaneous speech communication system using frequency division according to the present invention is applied, as shown in FIG. Eliminate filter 3, upstream low-pass filter 4, upstream A / D converter 5, D controlled by CPU 19
/ A converter 6 and upstream analog switch 7, adder 8, downlink originating side bandpass filter 9, downlink arriving side bandpass filter 10, downlink lowpass filter 11, downlink A /
D converter 12, downlink analog switch 13, speaker 1
4, CP with built-in Echo Cancel calculation program
Consists of U19. The output side of the microphone 1 is connected to the input sides of the up-and-down side low-frequency eliminate filter 2, the up-and-down side low-frequency eliminate filter 3, and the up-low-pass filter 4, and the up-and-down low-frequency eliminate filter 2.
The output side of the upstream landing side low-frequency elimination filter 3 is C
It is connected to the normally closed and normally open contacts of the upstream analog switch 7 under the control of the PU 19. The movable contact of the up analog switch 7 is controlled by the CPU 19 D
The transmission line L 1 is connected to the terminal T 1 via the adder 8 to which the output side of the / A converter 6 is connected. Further, the output side of the upstream low pass filter 4 is connected to the CPU 19 via the upstream A / D converter 5.
【0010】下り伝送路L2が接続された端子T2は下り
発側バンドパスフィルタ9、下り着側バンドパスフィル
タ10、下りローパスフィルタ11の入力側と接続さ
れ、下り発側バンドパスフィルタ9、下り着側バンドパ
スフィルタ10の出力側はCPU19の制御をうける下
りアナログスイッチ13の常閉、常開接点にそれぞれ接
続される。また、下りアナログスイッチ13の可動接点
はスピーカ14と接続される。更に、下りローパスフィ
ルタ11の出力側は下りA/D変換器12を介してCP
U19と接続される。The terminal T 2 to which the downlink transmission line L 2 is connected is connected to the input side of the downlink originating side bandpass filter 9, the downlink destination side bandpass filter 10, and the downlink lowpass filter 11, and the downlink originating side bandpass filter 9 is connected. The output side of the downstream arrival side band pass filter 10 is connected to the normally closed and normally open contacts of the downstream analog switch 13 under the control of the CPU 19. Further, the movable contact of the downlink analog switch 13 is connected to the speaker 14. Further, the output side of the downlink low-pass filter 11 is connected to the CP via the downlink A / D converter 12.
Connected with U19.
【0011】上記構成の拡声用同時通話装置TE1が網
に接続されてない状態では上りアナログスイッチ7の常
閉接点と下りアナログスイッチ13の常閉接点はそれぞ
れの可動接点と閉成された儘である。この状態で網側を
呼出すと発側の上りローパスフィルタ4の出力側は図6
に示すように音声帯域の下限周波数f0から例えば10
00HZの周波数f1までの低域が通過し、この低域部
分が上りA/D変換器5によりデジタル信号に変換され
CPU19へ送出される。CPU19に内蔵されたエコ
ーキヤンセル演算プログラムは図6に示す下りローパス
フィルタ11の下り音声信号を参照して疑似エコーを演
算し、疑似エコーが減算された上り音声信号FSをD/
A変換器6へ送出する。D/A変換器6は疑似エコーが
減算された上り音声信号FSを加算器8へ送出する。な
お、下りアナログスイッチ13は動作してないので、ス
ピーカ14へは図2に示す下り発側バンドパスフィルタ
9の出力が送出される。一方、上り発側低域エリミイネ
エイトフィルタ2から出力される上り音声信号FSは図
3に示すように下限周波数f0〜1000HZの周波数
f1が除去され、10000HZの上限周波数f10まで
が図2に示す下り発側バンドパスフィルタ9の下り音声
信号FSの周波数f1〜f10に対するそれぞれの帯域で
相互に帯域阻止フィルタ又は帯域通過フィルタとして機
能する周波数波形となつている。このようにして、加算
器8から端子T1から伝送路L1へ送出される上り音声信
号FSは周波数f0〜周波数f1が加算された部分、周波
数f1〜f10の高域の一部が櫛形に通過又は除去された
部分となる。高域が櫛形に除去された部分は聽感が若干
低下するが、下り発側バンドパスフィルタ9では図2に
示すように通過部分は阻止、除去された部分は通過する
のでエコーキヤンセル用の上り、下りローパスフィルタ
4、11でエコーキヤンセルのサンプリング演算を実行
しない高域部分のハウリングを防止することができる。
なお、着信でフィルタ特性を切換えないと、双方の拡声
用同時通話装置TE1、TE1の上り発側低域エリミイネ
エイトフィルタ2と下り発側バンドパスフィルタ9が異
なる特性となり相互に周波数f1〜f10が阻止されるこ
とになるので、着信では図4、図5にしめすように上り
発側低域エリミイネエイトフィルタ2は上り着側低域エ
リミイネエイトフィルタ3へ、下り発側バンドパスフィ
ルタ9は下り着側バンドパスフィルタ10へ上りアナロ
グスイッチ7及び下りアナログスイッチ13で切換え
る。In the state where the voice communication simultaneous communication device TE 1 having the above-mentioned configuration is not connected to the network, the normally closed contact of the up analog switch 7 and the normally closed contact of the down analog switch 13 are closed with their respective movable contacts. Is. When the network side is called in this state, the output side of the originating low-pass filter 4 is shown in FIG.
As shown in, from the lower limit frequency f 0 of the voice band to, for example, 10
The low frequency band up to the frequency f 1 of 00HZ passes, and this low frequency band is converted into a digital signal by the upstream A / D converter 5 and sent to the CPU 19. The echo cancel operation program stored in the CPU 19 calculates a pseudo echo by referring to the downlink voice signal of the downlink low-pass filter 11 shown in FIG. 6, and outputs the uplink voice signal FS from which the pseudo echo is subtracted by D /
It is sent to the A converter 6. The D / A converter 6 sends the upstream audio signal FS from which the pseudo echo has been subtracted, to the adder 8. Since the downlink analog switch 13 is not operating, the output of the downlink originating side bandpass filter 9 shown in FIG. 2 is sent to the speaker 14. On the other hand, as shown in FIG. 3, the lower limit frequency f 0 to the frequency f 1 of 1000 HZ is removed and the upper limit frequency f 10 of 10000 HZ is included in the upstream voice signal FS output from the upstream low frequency band elimination filter 2. The frequency waveforms mutually function as a band stop filter or a band pass filter in the respective bands for the frequencies f 1 to f 10 of the downlink voice signal FS of the downlink originating side band pass filter 9 shown in FIG. In this way, the upstream audio signal FS sent from the adder 8 to the transmission line L 1 from the terminal T 1 is a portion in which the frequencies f 0 to f 1 are added, that is, one of high frequencies of frequencies f 1 to f 10. The part becomes a part which is passed or removed in a comb shape. Although the discomfort is slightly reduced in the portion where the high frequencies are removed in a comb shape, the passing portion is blocked and the portion where the removed portion is passed in the downstream emission side bandpass filter 9 passes up because of the echo canceling as shown in FIG. It is possible to prevent howling in the high frequency range where the sampling calculation of the echo cancellation is not performed by the downlink low-pass filters 4 and 11.
If the filter characteristics are not switched for an incoming call, both the voice boosting simultaneous communication devices TE 1 and TE 1 have different characteristics between the upstream originating low-pass eliminate filter 2 and the downstream originating band-pass filter 9. Since 1 to f 10 are blocked, as shown in FIGS. 4 and 5, when the incoming call arrives, the upstream originating low-pass eliminate filter 2 goes to the incoming destination low-pass eliminate filter 3 and the outgoing originating side. The bandpass filter 9 is switched to the downstream arrival side bandpass filter 10 by the upstream analog switch 7 and the downstream analog switch 13.
【0012】尚、上りアナログスイッチ7及び下りアナ
ログスイッチ13の動作、復旧は発信、着発に対応して
おこなわれ、通話方向の変化では不動である。また、常
開、常閉と発信、着発の対応は適宜定める。上記実施例
では周波数分割を用いた拡声同時通話方式を拡声用同時
通話装置TEに組込んだ例について説明したが、これに
限定せず、インターホン、PBXの拡声トランク、無線
機等に適用してもよい。The operation and recovery of the upstream analog switch 7 and the downstream analog switch 13 are carried out in response to originating and terminating calls, and they are immovable even when the call direction changes. Correspondence between normally open, normally closed, outgoing and incoming calls will be determined as appropriate. In the above embodiment, an example in which the loudspeaker simultaneous call system using frequency division is incorporated into the loudspeaker simultaneous talk device TE has been described, but the invention is not limited to this, and is applied to an intercom, a PBX loudspeaker trunk, a radio device, or the like. Good.
【0013】上記実施例における周波数分割を用いた拡
声同時通話方式のアナログスイッチ及びフィルタはCP
U等の演算機能をもった素子で形成してもよい。上記実
施例におけるフィルタの通過、阻止帯域は上記実施例の
組合せに限定しない。The analog switch and filter of the loudspeaker simultaneous call system using frequency division in the above embodiment is CP.
It may be formed of an element having an arithmetic function such as U. The pass band and stop band of the filter in the above embodiment are not limited to the combination of the above embodiments.
【0014】[0014]
【発明の効果】本発明による周波数分割を用いた拡声同
時通話方式は、マイクから出力される上り音声信号とス
ピーカへ入力される下り音声信号を低域と高域に分割
し、上り音声信号の低域は下り音声信号の低域を参照し
て作成された疑似エコーを減算した上り音声信号で通話
し、上り、下り音声信号の高域は発信、着信等の呼発生
要因により定められた要素で相補的に対応して通過、阻
止させるよう周波数分割しこれにより、エコーキヤンセ
ル機能を改善し、音声信号の全域に亘つて、周囲環境の
変動や、双方の通話者が同時に送話を行なうダブルトー
ク時に安定した動作が図れる効果がある。As described above, according to the loudspeaker simultaneous call system using frequency division of the present invention, the upstream voice signal output from the microphone and the downstream voice signal input to the speaker are divided into a low frequency band and a high frequency band, and The low frequency band is the element that is determined by the call generation factors such as outgoing and incoming, and the high frequency band of the upstream and downstream audio signals is made by talking with the upstream audio signal after subtracting the pseudo echo created by referring to the low frequency band of the downstream audio signal. In this way, the frequency division is performed so as to pass and block in a complementary manner, thereby improving the echo cancel function, and changing the surrounding environment and double-calling by both callers simultaneously over the entire voice signal. The effect is that stable operation can be achieved during talk.
【図1】本発明による周波数分割を用いた拡声同時通話
方式を適用した拡声用同時通話装置の一実施例を示すブ
ロック図。FIG. 1 is a block diagram showing an embodiment of a simultaneous voice communication device to which a simultaneous voice communication system using frequency division according to the present invention is applied.
【図2】本発明による周波数分割を用いた拡声同時通話
方式を適用した拡声用同時通話装置の下り発側バンドパ
スフィルタの特性図。FIG. 2 is a characteristic diagram of a bandpass filter on the outgoing call side of a simultaneous voice communication device for voice amplification to which a simultaneous voice communication system using frequency division according to the present invention is applied.
【図3】本発明による周波数分割を用いた拡声同時通話
方式を適用した拡声用同時通話装置の上り発側低域エリ
ミイネエイトフィルタの特性図。FIG. 3 is a characteristic diagram of a low-pass eliminate filter on the outgoing side of a loudspeaker simultaneous speech communication apparatus to which a loudspeaker simultaneous speech communication system using frequency division according to the present invention is applied.
【図4】本発明による周波数分割を用いた拡声同時通話
方式を適用した拡声用同時通話装置の下り着側バンドパ
スフィルタの特性図。FIG. 4 is a characteristic diagram of a downlink destination side band-pass filter of a simultaneous voice-up communication device to which a voice-up simultaneous communication system using frequency division according to the present invention is applied.
【図5】本発明による周波数分割を用いた拡声同時通話
方式を適用した拡声用同時通話装置の上り着側低域エリ
ミイネエイトフィルタの特性図。FIG. 5 is a characteristic diagram of an incoming / outgoing side low-pass eliminate filter of a simultaneous voice communication system for loudspeakers to which a simultaneous voice communication system using frequency division according to the present invention is applied.
【図6】本発明による周波数分割を用いた拡声同時通話
方式を適用した拡声用同時通話装置の上の上り、下りロ
ーパスフィルタの特性図。FIG. 6 is a characteristic diagram of the upstream and downstream low-pass filters of the simultaneous voice communication device for loudspeaker to which the simultaneous voice communication system using frequency division according to the present invention is applied.
【図7】従来の拡声同時通話方式を適用した拡声用同時
通話装置のブロック図。FIG. 7 is a block diagram of a simultaneous loudspeaker system that applies a conventional loudspeaker system.
1・・・・・・マイク 2・・・・・・上り発側低域エリミイネエイトフィルタ(分割
された高域通過フィルタ) 3・・・・・・上り着側低域エリミイネエイトフィルタ(分割
された高域通過フィルタ) 4・・・・・・上りローパスフィルタ 7・・・・・・上りアナログスイッチ 9・・・・・・下り発側バンドパスフィルタ(分割された低域
通過、高域一部阻止フィルタ) 10・・・・・・下り着側バンドパスフィルタ(分割された低
域通過、高域一部阻止フィルタ) 11・・・・・・下りローパスフィルタ 13・・・・・・下りアナログスイッチ L1・・・・・・上り伝送路 L2・・・・・・下り伝送路1 ・ ・ Microphone 2 ・ ・ Upstream side low-pass eliminate filter (divided high-pass filter) 3 ・ ・ Upward destination low-pass eliminate filter ( Divided high-pass filter) 4 ... Upstream low-pass filter 7 ...- Upstream analog switch 9 ...- Down-stream side band-pass filter (divided low-pass, high-pass) Partial band rejection filter) 10 ... Downbound destination bandpass filter (divided low-pass, high band part rejection filter) 11 ... Downstream lowpass filter 13 ...・ Downstream analog switch L 1・ ・ Upstream transmission line L 2・ ・ ・ Downstream transmission line
Claims (1)
ーカへ入力される下り音声信号を低域と高域に分割し、
上り音声信号の低域は下り音声信号の低域を参照して作
成された疑似エコーを減算した上り音声信号で通話し、
上り、下り音声信号の高域は発信、着信等の呼発生要因
により定められた要素で相補的に対応して通過、阻止さ
せるよう周波数分割した上り、下り音声信号で通話する
ことを特徴とする周波数分割を用いた拡声同時通話方
式。1. An upstream audio signal output from a microphone and a downstream audio signal input to a speaker are divided into a low band and a high band,
For the low frequency band of the upstream voice signal, talk with the upstream voice signal by subtracting the pseudo echo created by referring to the low frequency band of the downstream voice signal,
The high frequencies of the upstream and downstream voice signals are characterized by the fact that the call is transmitted using upstream and downstream voice signals that are frequency-divided so as to complementarily pass and block corresponding to elements determined by call generation factors such as outgoing and incoming calls. A loud voice simultaneous call system using frequency division.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP21545991A JPH0555961A (en) | 1991-08-27 | 1991-08-27 | Loud-speaker simultaneous speech system using frequency division |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP21545991A JPH0555961A (en) | 1991-08-27 | 1991-08-27 | Loud-speaker simultaneous speech system using frequency division |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0555961A true JPH0555961A (en) | 1993-03-05 |
Family
ID=16672727
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP21545991A Pending JPH0555961A (en) | 1991-08-27 | 1991-08-27 | Loud-speaker simultaneous speech system using frequency division |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0555961A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6153683A (en) * | 1996-11-14 | 2000-11-28 | Kawasaki Steel Corporation | Glass long fiber-reinforced thermoplastic resin form having conductivity and manufacturing method thereof |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61121624A (en) * | 1984-11-19 | 1986-06-09 | Fujitsu Ltd | Echo control system |
JPS63294018A (en) * | 1987-05-27 | 1988-11-30 | Oki Electric Ind Co Ltd | Loud-speaker telephone set |
JPS645250A (en) * | 1987-06-29 | 1989-01-10 | Oki Electric Ind Co Ltd | Howling prevention circuit for loudspeaker system telephone set |
JPS6429094A (en) * | 1987-07-24 | 1989-01-31 | Nippon Telegraph & Telephone | Echo erasing device |
-
1991
- 1991-08-27 JP JP21545991A patent/JPH0555961A/en active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61121624A (en) * | 1984-11-19 | 1986-06-09 | Fujitsu Ltd | Echo control system |
JPS63294018A (en) * | 1987-05-27 | 1988-11-30 | Oki Electric Ind Co Ltd | Loud-speaker telephone set |
JPS645250A (en) * | 1987-06-29 | 1989-01-10 | Oki Electric Ind Co Ltd | Howling prevention circuit for loudspeaker system telephone set |
JPS6429094A (en) * | 1987-07-24 | 1989-01-31 | Nippon Telegraph & Telephone | Echo erasing device |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6153683A (en) * | 1996-11-14 | 2000-11-28 | Kawasaki Steel Corporation | Glass long fiber-reinforced thermoplastic resin form having conductivity and manufacturing method thereof |
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