CN103475763A - Conversation echo canceling circuit of PSTN communication terminal - Google Patents
Conversation echo canceling circuit of PSTN communication terminal Download PDFInfo
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- CN103475763A CN103475763A CN2013104513651A CN201310451365A CN103475763A CN 103475763 A CN103475763 A CN 103475763A CN 2013104513651 A CN2013104513651 A CN 2013104513651A CN 201310451365 A CN201310451365 A CN 201310451365A CN 103475763 A CN103475763 A CN 103475763A
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Abstract
The invention discloses a conversation echo canceling circuit of a PSTN communication terminal. The conversation echo canceling circuit comprises a telephone terminal, a telephone switchboard, a reverse canceller and a suppression circuit. The telephone terminal comprises a microphone input end and a horn output end. The telephone switchboard is used for receiving sound signals at the microphone input end, carrying out conversion on the outputted sound signals through a rectifier bridge and then transmitting the converted sound signals to the horn output end. The reverse canceller is used for enabling the sound signals at the microphone input end not to be transmitted to the horn output end. The suppression circuit is used for canceling the sound signals entering the horn output end from the microphone input end. The conversation echo canceling circuit of the PSTN communication terminal cancels echoes generated at the PSTN communication terminal during a phone call and enables conversations to be more smoothly.
Description
Technical field
The present invention relates to a PSTN communication terminal and eliminate the circuit of talk echo.
Background technology
When using the PSTN communication terminal to be exchanged, because telephone wire is two-way transmission, each telephone terminal is when passing through Mike's sound import, and the loudspeaker that receive sound also work, cause the sound be transported on telephone wire by Mike to be received by loudspeaker again, echogenicity; And Mike can collect the sound that loudspeaker send when gathering sound, then is sent to another telephone terminal, echogenicity.
Summary of the invention
The present invention is directed to above-mentioned deficiency, proposed the circuit of a PSTN communication terminal elimination talk echo.
Technical scheme provided by the invention is:
A PSTN communication terminal is eliminated the circuit of talk echo, comprising:
A telephone terminal, it comprises Mike's input and a loudspeaker output;
One is used for receiving the acoustical signal of described Mike's input and will exports acoustical signal through being passed to the telephone exchange of described loudspeaker output after the rectifier bridge conversion;
An acoustical signal that makes Mike's input can not be passed to the reverse Canceller of described loudspeaker output;
The inhibition circuit that the acoustical signal of a loudspeaker output that will enter from Mike's input is eliminated.
Preferably, described PSTN communication terminal is eliminated in the circuit of talk echo, and described inhibition circuit comprises:
The acoustical signal of the described loudspeaker output entered from Mike's input is carried out to Mike's gain adjusting circuit of gain-adjusted;
By the gain of Mike's gain adjusting circuit output, the low noise of little acoustical signal filtering is eliminated circuit;
The output acoustical signal of described telephone exchange is carried out to the Computation of Horn Gain regulating circuit of gain-adjusted;
Gather the signal amplification circuit of the acoustical signal of Mike's input;
Respectively the output acoustical signal of the acoustical signal of Mike's input of collecting and telephone exchange is surveyed and is done the detection comparison circuit of signal comparison process;
Control the gain control circuit of described Mike's gain adjusting circuit and described Computation of Horn Gain regulating circuit.
Preferably, described PSTN communication terminal is eliminated in the circuit of talk echo, described reverse Canceller, and it comprises two inputs, and first input end connects described Mike's input, and the second input connects described telephone exchange; The acoustical signal of described Mike's input, its first's acoustical signal is transported to described first input end, and through anti-phase Canceller negate to; The second portion acoustical signal is transported on the telephone wire that connects telephone exchange and anti-phase Canceller; Described second portion acoustical signal, its a part of acoustical signal is sent on telephone exchange, another part acoustical signal is sent to the second input of described reverse Canceller, described another part acoustical signal and described first acoustical signal are cancelled out each other under the effect of anti-phase Canceller, can not be sent to the loudspeaker output.
Preferably, described PSTN communication terminal is eliminated in the circuit of talk echo, the acoustical signal of described Mike's input is done the used time, and the loudspeaker output can not produce the output acoustical signal by telephone exchange, therefore suppresses circuit the acoustical signal of described Mike's input is not acted on; When described loudspeaker output has the output acoustical signal, the part output acoustical signal of described loudspeaker output can be sent to Mike's input.
Preferably, described PSTN communication terminal is eliminated in the circuit of talk echo, described gain control circuit, its input connects the output of described detection comparison circuit, an output connects described Mike's gain adjusting circuit, another output connects described Computation of Horn Gain regulating circuit, and reach the gain of the part output acoustical signal of the loudspeaker output of controlling the described Mike's of being sent to input by controlling Mike's gain adjusting circuit, reach the gain of the output acoustical signal of controlling described telephone exchange by controlling the Computation of Horn Gain regulating circuit;
The gain of the part output acoustical signal of the loudspeaker output of the described Mike's of being sent to input reduces, and this acoustical signal is eliminated the circuit filtering by described low noise; The gain of the output acoustical signal of described telephone exchange strengthens, and this acoustical signal is exported from the loudspeaker output.
PSTN communication terminal of the present invention is eliminated the circuit of talk echo, and the echo that the sound of a telephone terminal input is sent to this telephone terminal output is eliminated by reverse Canceller, does not affect the normal transmission of this sound; The sound collection of described telephone terminal output is passed through to the inhibition circuit for eliminating to the echo of the input of this telephone terminal, do not affect the normal output of the sound of this telephone terminal output.
The accompanying drawing explanation
Fig. 1 is the circuit diagram that PSTN communication terminal of the present invention is eliminated talk echo.
Embodiment
Below in conjunction with accompanying drawing, the present invention is described in further detail, to make those skilled in the art, with reference to the specification word, can implement according to this.
As shown in Figure 1, the invention provides the circuit that a PSTN communication terminal is eliminated talk echo, comprising: a telephone terminal, it comprises Mike's input and a loudspeaker output; One be used for receiving the acoustical signal A of described Mike's input and will export acoustical signal H through rectifier bridge conversion become afterwards direct current acoustical signal B be passed to described loudspeaker output telephone exchange; An acoustical signal A who makes Mike's input can not be passed to the reverse Canceller of described loudspeaker output; The inhibition circuit that the acoustical signal G of a part of loudspeaker output that will enter from Mike's input eliminates.
Described PSTN communication terminal is eliminated in the circuit of talk echo, and described inhibition circuit comprises: the Mike's gain adjusting circuit that the acoustical signal G of the loudspeaker output that enters from Mike's input is carried out to gain-adjusted; The low noise of the acoustical signal G filtering of Mike's gain adjusting circuit output is eliminated to circuit; The output acoustical signal B of described telephone exchange is carried out to the Computation of Horn Gain regulating circuit of gain-adjusted; Gather the signal amplification circuit of the acoustical signal of Mike's input; Respectively the output acoustical signal B of the acoustical signal G of Mike's input of collecting and telephone exchange is surveyed and is done the detection comparison circuit of signal comparison process; Control the gain control circuit of described Mike's gain adjusting circuit and described Computation of Horn Gain regulating circuit.
Described PSTN communication terminal is eliminated in the circuit of talk echo, described reverse Canceller, and it comprises two inputs, and first input end connects described Mike's input, and the second input connects described telephone exchange; The acoustical signal A of described Mike's input, the acoustical signal C of its first is transported to described first input end, and through anti-phase Canceller negate to; Second portion acoustical signal D is transported on the telephone wire that connects telephone exchange and anti-phase Canceller; Described second portion acoustical signal D, its a part of acoustical signal E is sent on telephone exchange, another part acoustical signal F is sent to the second input of described reverse Canceller, described another part acoustical signal F and the described acoustical signal C of first cancel out each other under the effect of anti-phase Canceller, can not be sent to the loudspeaker output.
Described PSTN communication terminal is eliminated in the circuit of talk echo, and the acoustical signal A of described Mike's input does the used time, and the loudspeaker output can not produce output acoustical signal H by telephone exchange, therefore suppresses circuit the acoustical signal A of described Mike's input is not acted on; When described loudspeaker output has output acoustical signal H, the part output acoustical signal G of described loudspeaker output can be sent to Mike's input.
When the acoustical signal A of Mike's input enters into the circuit that described PSTN communication terminal is eliminated talk echo, described acoustical signal A faces two branch roads, a branch road is, through Mike's gain adjusting circuit, low noise is eliminated circuit, and a part of signal C arrives reverse Canceller, and negate is to value, part signal F is transported on telephone exchange, and a part of signal E offsets through reverse Canceller and described signal C through telephone wire; Another branch road is through signal amplifier, is detected comparison circuit gathered, still, at this moment do not have output AC signal H on telephone exchange, the direct current signal B also do not converted to by described AC signal H, survey comparison circuit and do not work, and can not affect the transmission of described acoustical signal A.
Described PSTN communication terminal is eliminated in the circuit of talk echo, described gain control circuit, its input connects the output of described detection comparison circuit, an output connects described Mike's gain adjusting circuit, another output connects described Computation of Horn Gain regulating circuit, and reach the gain of the part output acoustical signal G of the loudspeaker output of controlling the described Mike's of being sent to input by controlling Mike's gain adjusting circuit, reach the gain of the output acoustical signal B that controls described telephone exchange by controlling the Computation of Horn Gain regulating circuit;
The gain of the part output acoustical signal G of the loudspeaker output of the described Mike's of being sent to input reduces, and this acoustical signal G eliminates the circuit filtering by described low noise; The gain of the output acoustical signal B of described telephone exchange strengthens, and this acoustical signal B exports from the loudspeaker output.
The pattern of gain control circuit has three kinds:
Transmission mode: gain control circuit controls Mike's gain adjusting circuit, make Mike's gain-adjusted to maximum, gain control circuit controls Computation of Horn Gain regulating circuit, make Computation of Horn Gain be adjusted to minimum, the gain of the output acoustical signal B of loudspeaker output is little, and it is less to be sent to the gain of part output acoustical signal G of loudspeaker output of Mike's input, even by Mike's gain adjusting circuit, the gain of described acoustical signal G is also little, is regarded as low noise and is directly filtered by the low noise filtering circuit.
Receiving mode: gain control circuit controls Mike's gain adjusting circuit, make Mike's gain-adjusted reach minimum, gain control circuit controls Computation of Horn Gain regulating circuit, make Computation of Horn Gain be adjusted to maximum, the gain of part output acoustical signal G of loudspeaker output that is sent to Mike's input is large, described acoustical signal G is by Mike's gain adjusting circuit, and acoustical signal G is faint, is regarded as low noise and is directly filtered by the low noise filtering circuit.
Idle pulley: gain control circuit controls Mike's gain adjusting circuit, make Mike's gain-adjusted between maximum and minimum value, gain control circuit controls Computation of Horn Gain regulating circuit, Computation of Horn Gain is adjusted between maximum and minimum value, meet the Mode change of the transmission acoustical signal of the reception acoustical signal of loudspeaker output and Mike's input, the loudspeaker output normally receives acoustical signal, and Mike's input normally sends acoustical signal.
In the present embodiment, when described acoustical signal G is sent to Mike's input from the loudspeaker output, described acoustical signal B is sent to the loudspeaker output, signal amplifier gathers amplification to acoustical signal, survey comparison circuit to described acoustical signal B and G gathered, comparison process, by gain control circuit, to the large signal that gains, the gain-adjusted of this signal is increased; To the little signal that gains, the gain-adjusted of this signal is reduced, acoustical signal G is sent to the acoustical signal of Mike's input by air by acoustical signal B, the gain of the ratio of gains acoustical signal B of acoustical signal G is little, and therefore, acoustical signal B sends out smoothly, acoustical signal G is after Mike's gain-adjusted, gain less, then eliminate the circuit filtering by low noise, realized the elimination of the acoustical signal of the loudspeaker output to entering from Mike's input.
Although embodiment of the present invention are open as above, but it is not restricted to listed utilization in specification and execution mode, it can be applied to various applicable the field of the invention fully, for those skilled in the art, can easily realize other modification, therefore do not deviating under the universal that claim and equivalency range limit, the present invention is not limited to specific details and illustrates here and the legend of describing.
Claims (5)
1. the circuit of a PSTN communication terminal elimination talk echo, is characterized in that,
Comprise:
A telephone terminal, it comprises Mike's input and a loudspeaker output;
One is used for receiving the acoustical signal of described Mike's input and will exports acoustical signal through being passed to the telephone exchange of described loudspeaker output after the rectifier bridge conversion;
An acoustical signal that makes Mike's input can not be passed to the reverse Canceller of described loudspeaker output;
The inhibition circuit that the acoustical signal of a loudspeaker output that will enter from Mike's input is eliminated.
2. a PSTN communication terminal according to claim 1 is eliminated the circuit of talk echo, it is characterized in that, described inhibition circuit comprises:
The acoustical signal of the described loudspeaker output entered from Mike's input is carried out to Mike's gain adjusting circuit of gain-adjusted;
By the gain of Mike's gain adjusting circuit output, the low noise of little acoustical signal filtering is eliminated circuit;
The output acoustical signal of described telephone exchange is carried out to the Computation of Horn Gain regulating circuit of gain-adjusted;
Gather the signal amplification circuit of the acoustical signal of Mike's input;
Respectively the output acoustical signal of the acoustical signal of Mike's input of collecting and telephone exchange is surveyed and is done the detection comparison circuit of signal comparison process;
Control the gain control circuit of described Mike's gain adjusting circuit and described Computation of Horn Gain regulating circuit.
3. a PSTN communication terminal according to claim 1 is eliminated the circuit of talk echo, it is characterized in that, and described reverse Canceller, it comprises two inputs, and first input end connects described Mike's input, and the second input connects described telephone exchange; The acoustical signal of described Mike's input, its first's acoustical signal is transported to described first input end, and through anti-phase Canceller negate to; The second portion acoustical signal is transported on the telephone wire that connects telephone exchange and anti-phase Canceller; Described second portion acoustical signal, its a part of acoustical signal is sent on telephone exchange, another part acoustical signal is sent to the second input of described reverse Canceller, described another part acoustical signal and described first acoustical signal are cancelled out each other under the effect of anti-phase Canceller, can not be sent to the loudspeaker output.
4. a PSTN communication terminal according to claim 1 is eliminated the circuit of talk echo, it is characterized in that, the acoustical signal of described Mike's input is done the used time, the loudspeaker output can not produce the output acoustical signal by telephone exchange, therefore suppresses circuit the acoustical signal of described Mike's input is not acted on; When described loudspeaker output has the output acoustical signal, the part output acoustical signal of described loudspeaker output can be sent to Mike's input.
5. a PSTN communication terminal according to claim 2 is eliminated the circuit of talk echo, it is characterized in that, described gain control circuit, its input connects the output of described detection comparison circuit, an output connects described Mike's gain adjusting circuit, another output connects described Computation of Horn Gain regulating circuit, and reach the gain of the part output acoustical signal of the loudspeaker output of controlling the described Mike's of being sent to input by controlling Mike's gain adjusting circuit, reach the gain of the output acoustical signal of controlling described telephone exchange by controlling the Computation of Horn Gain regulating circuit,
The gain of the part output acoustical signal of the loudspeaker output of the described Mike's of being sent to input reduces, and this acoustical signal is eliminated the circuit filtering by described low noise; The gain of the output acoustical signal of described telephone exchange strengthens, and this acoustical signal is exported from the loudspeaker output.
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| Application Number | Priority Date | Filing Date | Title |
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| CN2013104513651A CN103475763A (en) | 2013-09-26 | 2013-09-26 | Conversation echo canceling circuit of PSTN communication terminal |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2013104513651A CN103475763A (en) | 2013-09-26 | 2013-09-26 | Conversation echo canceling circuit of PSTN communication terminal |
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| CN2013104513651A Pending CN103475763A (en) | 2013-09-26 | 2013-09-26 | Conversation echo canceling circuit of PSTN communication terminal |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101682810A (en) * | 2007-05-16 | 2010-03-24 | 雅马哈株式会社 | Video conference device |
| CN102025852A (en) * | 2009-09-23 | 2011-04-20 | 宝利通公司 | Detection and suppression of returned audio at near-end |
| CN102223456A (en) * | 2010-04-14 | 2011-10-19 | 华为终端有限公司 | Echo signal processing method and apparatus thereof |
| CN102405634A (en) * | 2009-04-21 | 2012-04-04 | 松下电工株式会社 | Speakerphone apparatus |
| TW201218183A (en) * | 2010-06-04 | 2012-05-01 | Apple Inc | Active noise cancellation decisions in a portable audio device |
-
2013
- 2013-09-26 CN CN2013104513651A patent/CN103475763A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101682810A (en) * | 2007-05-16 | 2010-03-24 | 雅马哈株式会社 | Video conference device |
| CN102405634A (en) * | 2009-04-21 | 2012-04-04 | 松下电工株式会社 | Speakerphone apparatus |
| CN102025852A (en) * | 2009-09-23 | 2011-04-20 | 宝利通公司 | Detection and suppression of returned audio at near-end |
| CN102223456A (en) * | 2010-04-14 | 2011-10-19 | 华为终端有限公司 | Echo signal processing method and apparatus thereof |
| TW201218183A (en) * | 2010-06-04 | 2012-05-01 | Apple Inc | Active noise cancellation decisions in a portable audio device |
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| PB01 | Publication | ||
| ASS | Succession or assignment of patent right |
Owner name: RED BENCH TECHNOLOGY CO., LTD. Free format text: FORMER OWNER: HANDAER COMMUNICATION TECHNOLOGY (BEIJING) CO., LTD. Effective date: 20131216 |
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| C41 | Transfer of patent application or patent right or utility model | ||
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Free format text: CORRECT: ADDRESS; FROM: 100085 HAIDIAN, BEIJING TO: 100080 HAIDIAN, BEIJING |
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| TA01 | Transfer of patent application right |
Effective date of registration: 20131216 Address after: 100080, Haidian District, Zhichun Road, No. 49, seven floor, Beijing Applicant after: Red Bench Technology Co., Ltd. Address before: 100085, Beijing, Haidian District Anning Road East, No. 18 Guanghua Pioneer Park, research building, 4 floor Applicant before: Handaer Communication Technology (Beijing) Co., Ltd. |
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Application publication date: 20131225 |