CN103796135B - Dynamic loudspeaker management with echo cancellor - Google Patents
Dynamic loudspeaker management with echo cancellor Download PDFInfo
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- CN103796135B CN103796135B CN201310717528.6A CN201310717528A CN103796135B CN 103796135 B CN103796135 B CN 103796135B CN 201310717528 A CN201310717528 A CN 201310717528A CN 103796135 B CN103796135 B CN 103796135B
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Abstract
A kind of echo cancelling system includes dynamic loudspeaker management (DSM) module, current/voltage sensing amplifier, sound pressure level (SPL) model module and Echo Canceller.The exemplary DSM modules can receive remote signaling, and for generating modified remote signaling and multiple parameters output.Illustrative current/voltage sensing amplifier is coupled to the modified remote signaling, and generates amplifier output, the output of voltage (V) parameter and the output of electric current (I) parameter.Illustrative sound pressure level (SPL) model module is coupled to the multiple parameters output of DSM modules, and the SPL for generating prediction.The illustrative echo canceller module in response to prediction SPL and near end signal, and for generating echo cancellation output signal.
Description
Cross reference to related applications
This application claims on October 31st, 2012 is submitting, U.S. Provisional Patent Application USSN61/721010,61/
721015 and 61/721021 equity, entire contents are incorporated by reference into this.
Background technology
Current trend is the output in the Microspeaker of plurality of devices (such as functional mobile phone, smart mobile phone and tablet)
End provides more loud sound pressure level (" SPL ").Loud speaker herein is alternatively also referred to as " loudspeaker ".As this field skill
Well known to art personnel, SPL is in the measurement amount of the sound pressure variations of loud speaker forepart caused by speaker operation.
When increasing the SPL grades in speaker-phone problem appear to is that it typically results in speaker operation in inelastic region
In domain.When equipment is operated with speakerphone mode, become difficult to effectively eliminate between loud speaker and microphone by straight
Connect or the acoustic path that reflects caused by echo.
Fig. 1 is the block diagram for the certain echo canceller systems for showing the prior art.In the first example, Fig. 1 shows biography
Remote signaling (" voice ") R1 as reference is fed to sef-adapting filter, the adaptive filter by the Echo Canceller of system
Wave device models sound feedback (" echo ").The output of sef-adapting filter is subtracted from the output of microphone, to reduce
Echo in microphone signal.In the second example, reference signal R1 is omitted, and will come from and be attached to loud speaker carton
(cone) the reference signal R2 of the sensor S (for example, accelerometer or microphone) on is input in sef-adapting filter.
Problem caused by first exemplary operations of the block diagram of Fig. 1 is without accurately representing or not raising with reference to R1
" model " of true SPL variations at sound device, so as to cause poor echo cancellor.Second exemplary operations cause preferably to represent
Or the SPL " model " of preferable loudspeaker, but it is only this shadow sensor S is attached to loudspeaker carton as cost
The SPL characteristics of loud speaker have been rung, and have increased the cost of system.
Error between the near end signal of acoustic feedback signal (for example, R1 or R2) and microphone output being modeled can quilt
For adjusting sef-adapting filter and improving its performance.At steady state, sef-adapting filter study is accurately to sound
Feedback is modeled, and make to minimize the error.However, due to being fed to the reference (such as RI) of traditional Echo Canceller not
The nonlinear information that any related loudspeaker introduces is carried, therefore the Echo Canceller of sensor S is not used in the prior art
It will be unable to eliminate non-linear component, be remained so as to cause there is more echoes in the voice after echo cancellor.
Schemed by reading following description and studying the number pair in attached drawing, it is to those skilled in the art, existing
These or other limitations in technology will be apparent.
Invention content
In one embodiment, echo cancelling system is elaborated by way of example, and not limitation, the echo cancelling system
Disappear including dynamic loudspeaker management (DSM) module, current/voltage sensing amplifier, sound pressure level (SPL) model module and echo
Except device.The illustrative DSM modules can receive remote signaling and for generating modified remote signaling and multiple parameters output.It should
Illustrative current/voltage sensing amplifier is coupled to the modified remote signaling and generates amplifier output, voltage (V) parameter
Output and the output of electric current (I) parameter.Illustrative sound pressure level (SPL) model module is coupled to the multiple parameters of DSM modules
Export and be used to generate the SPL of prediction.The illustrative echo canceller module in response to prediction SPL and near end signal, and
For generating echo cancellation output signal.
In embodiment, elaborate what loudspeaker sound pressure level (SPL) was modeled by way of example, and not limitation
Method, the method includes：Measurement is applied to the voltage (V) of loudspeaker coil and flows through the electric current (I) of loudspeaker coil, with
Generate V parameters and I parameters；The impedance of loudspeaker coil is modeled according to V parameters and I parameters, it is defeated to provide multiple parameters
Go out；It is modeled using multiple parameters output come the SPL of the prediction to being used for loud speaker；And the SPL of prediction is applied to back
Sound arrester is used as with reference to signal.In certain unrestricted examples, multiple parameters output includes resonant frequency (Fc) parameter
Output and total quality factor (Q) parameter export.In other unrestricted examples, multiple parameters output includes d.c. coils
Resistance (Rdc) parameter output.In another unrestricted example, multiple parameters output includes V parameters and/or modified distal end
Signal parameter.In certain unrestricted examples, near end signal is applied to Echo Canceller.
The advantages of exemplary system and process disclosed herein, is to raise one's voice being not through sensor etc. being attached to
Device carton and in the case of influencing the SPL of loud speaker, obtain the accurate prediction of loud speaker SPL.
Another advantage of exemplary system and process disclosed herein be by the SPL of loud speaker is carried out accurately and
Dynamically model, it can be by obtaining louder, clearer sound in the loudspeaker and chest of small form factor.
Another advantage of exemplary system and process disclosed herein is generation SPL models, and the SPL models are included in
The information of nonlinear correlation introduced during playing back to louder volume and by loudspeaker, so as to make the adaptive-filtering of Echo Canceller
Device can more effectively eliminate nonlinear acoustic feedback.
Be described below and study that number in attached drawing is secondary schemes by reading, to those skilled in the art, these or
Person's other embodiments, feature and advantage will be apparent.
Description of the drawings
Multiple exemplary embodiments are will now be described with reference to the attached figures, wherein, identical component is provided identical attached drawing
Label.These exemplary embodiments are intended to illustrate and not limit the present invention.View includes the following drawings：
Fig. 1 is the block diagram for the echo cancelling system for showing the prior art；
Fig. 2 is the block diagram for the exemplary dynamic loudspeaker management system for showing to have echo cancellor；And
Fig. 3 is the flow chart of exemplary SPL modeling process.
Specific embodiment
Fig. 1 is discussed with reference to the prior art.Fig. 2 is to elaborate dynamic loudspeaker by way of example, and not limitation
The block diagram of (" the DSM ") system 10 of management, dynamic loudspeaker management system 10 include DSM modules 12, SPL model modules 14, return
Sound canceller module 16 and current/voltage sensing amplifier 32.In this example, DSM systems 10 are coupled to portable electronic
The loudspeaker (" loud speaker ") 18 and " proximal end " microphone 20 of equipment (such as smart mobile phone, tablet computer etc.).This amplifies
Device 18 and microphone 20 are exposed to the ambient enviroment 22 that can have one or more reflectings surface 24, such as room.It is noted that
There is the acoustic path across the direct of air and reflection from loud speaker 18 to microphone 20, so as to lead to sound at microphone 20
Feedback.
DSM systems 10 have input 26, sometimes referred to as " distal end " input, and such as distal end can be included by being somebody's turn to do " distal end " input
Signal, referred to herein as " far-end speech ".Such as in the case of smart mobile phone, this can come from the radio frequency of phone
(RF) acceptor circuit.It is handled by DSM modules 12 by inputting 26, so that signal loudness maximizes, and is loudspeaker
18 modeling provides information.In the unrestricted example, the output 28 of amplifier 32 using the electric current I under voltage V come
Drive the coil of loudspeaker 18.
In the unrestricted example, DSM modules 12 include DSM control blocks 30 and loud speaker modeling device 34.The DSM is controlled
Clamp dog 30 has remote signaling as input and the revise signal as output, which, which is referred to herein as, is applied to
" the modified remote signaling " of the input terminal of amplifier 32.In this example, the output of DSM control blocks 30 is input to amplification
It in device 32 and is input in SPL model modules 14 via circuit 33 again, although can be omitted circuit 33 in other embodiments.
As described above, amplifier 32 provides output signal 28 for loud speaker 18, also voltage V is provided to loud speaker modeling device 34
With electric current I parameters.Loud speaker modeling device 34 provides output 35, which is input into DSM control blocks 30 and SPL model modules
In 14 the two.
SPL model modules 14 receive signal 36, which is one or more of following：DSM control blocks 30 via
Output that the output of circuit 33, loud speaker modeling device 34 are exported via the multiple parameters of circuit 35 and from amplifier 32
Voltage V parameters (in some embodiments, voltage V parameters can replace the parameter from DSM control blocks 30 in circuit 33).
Processing and signal Analysis 36 are utilized an algorithm to, for example to predict the SPL of loud speaker 18, so as to accurately to coming from surrounding ring
The transmission function of the acoustic feedback in border 22 is modeled.
In the embodiment illustrated by way of example, and not limitation, by assuming that loudspeaker 18 is interested at one
Given frequency range (for example, 0-4KHz) in second order (" linear ") system, loud speaker modeling device 34 utilize electric current I and voltage
V models come the impedance transfer function to the loudspeaker 18.Impedance is obtained using the technology of such as least square method for root
Transmission function.In other embodiments, for example nonlinear response can be modeled using other models and technology.
In unrestricted example, it can be calculated according to the impedance transfer function obtained by loud speaker modeling device 34 humorous
Vibration frequency " Fc " and entire quality factor " Q ".In a manner of non-limiting example, by using Fc the and Q parameters calculated,
The SPL transmission functions of loud speaker 18 can be modeled as second order (" linear ") high-pass filter.Alternatively, it is possible to generate higher
The system model of rank come reflect for example when with high amplitude come the nonlinear response of the loudspeaker 18 when driving loudspeaker 18.Pass through
SPL model modules 14, SPL transmission functions can be subsequently used to the voltage V for being applied to the coil of loudspeaker 18 transforming to its SPL
Response, SPL responses are subsequently input into echo canceller module 16.
In the non-limiting example, echo canceller module 16 can be conventional design, including sef-adapting filter
38 and adder 40.Sef-adapting filter 38 is in response to the prediction SPL that is generated by SPL model modules 14, and usually using being permitted
Multi-filter as closely as possible models the inverse of the transmission function of ambient enviroment 22 with postponing.Sef-adapting filter 38
Output be then summed together with the output of microphone 20, to eliminate acoustic feedback or output signal 42 at least partly
" echo ", referred herein as " echo cancellation signal " or " echo cancellor voice ".
The operation example of DSM systems shown in Fig. 2 is as follows.Remote signaling is handled by DSM modules 12, to reduce at higher time
Distortion under playback amount.Loud speaker modeling device 34 handles the sensing voltage V and electric current obtained from current/voltage sensing amplifier 32
I, to generate the output of the parameter on circuit 35, such as its resonant frequency Fc, quality factor (Q) and d.c. coil resistances (Rdc).Example
Such as, these parameters output can be used together with other signals by SPL model modules 14.It will be realized that the signal 36 include in height
The information of nonlinear correlation that sound is generated during playing back by loud speaker, so as to allow sef-adapting filter more effectively elimination sound
Feedback.
Fig. 3 is the flow chart of elaborate process 50 by way of example, and not limitation, the process 50 by Fig. 2 DSM systems
10 perform.In the non-limiting example, which flows through the electric current I of loudspeaker coil by sensing and is applied to coil
Voltage V, 52 start.Then, in operation 54, such as the loud speaker modeling device 34 using Fig. 2, by sensing electric current I and electricity
Pressure V is used to model the impedance of loudspeaker.Operation 56 using the loud speakers of 54 generation of operation impedance models, calculating and
Estimated resonant frequency Fc and total quality factor q.Operation 56 utilizes calculated Fc and Q parameters for example in the SPL pattern dies of Fig. 2
Loud speaker SPL models are obtained in block 14.Then, 60 are being operated, in a manner of non-limiting example, by voltage V (for example, coming from
The circuit 35 of Fig. 2) SPL model modules 14 are applied to, to generate the SPL of the prediction of loud speaker for example on the circuit of Fig. 2 15.Most
Afterwards, in operation 62, the SPL of prediction is applied to Echo Canceller 16, to provide desired echo cancellor.
It should be noted that in the foregoing example embodiment, output of the DSM control blocks 30 on circuit 33 is not by SPL moulds
Pattern block 14 uses.In interchangeable exemplary embodiment, output of the DSM control blocks 30 on circuit 33 is additionally used for line
Voltage V parameters on road 37, and in another interchangeable exemplary embodiment, DSM control blocks 30 are defeated on circuit 33
Go out to replace the voltage V parameters on circuit 37.The other parameters as similar purpose are also used to input.
For example, entirely or partially DSM systems 10 and thus can be provided using integrated circuit (" IC ") technology
The exemplary algorithm of implementation.In a manner of non-limiting example, DSM systems 10 can be used as audio frequency process IC or Digital Signal Processing
A part for device (" DSP ") is realized, for example, the Maxim Integrated Products of the San Jose in California have
Limit company, the part number of d/b/a Maxim Integrated " have broadband FlexSound processors for MAX98096
Audio network hub ".It should also be appreciated that the function of DSM modules 12, SPL model modules 14 and Echo Canceller 16 can be by
Hardware, software or its with reference to realizing.In another unrestricted example, the process can in addition by such as smart mobile phone or
Other processing units (for example, microprocessor) of the mobile equipment of tablet computer are realized.
Although describing various embodiments using specific nomenclature and device, these being merely to illustrate that property of description
Purpose.Used word is for describing rather than for limiting.It should be appreciated that without departing substantially from the disclosure write
In the case of the spirit and scope of various inventions that content and attached drawing are supported, those skilled in the art can carry out various changes or
Variation.Further, it is understood that various other embodiments can be exchanged with each other in whole or in part.Therefore, it should according to
The true spirit or scope of the present invention is explained claim rather than limitation or is forbidden.
Claims (13)
1. a kind of system for echo cancellor, including：
Dynamic loudspeaker management (DSM) module receives remote signaling, the output of voltage (V) parameter and the output of electric current (I) parameter,
And for generating modified remote signaling and multiple parameters output；
Current/voltage sensing amplifier is coupled to the modified remote signaling of institute and with amplifier output, the voltage parameter
Output and current parameters output；
Sound pressure level (SPL) model module, the multiple parameter for being coupled to the dynamic loudspeaker management module are exported and are used in combination
In the sound pressure level of generation prediction；And
Echo canceller module, in response to the sound pressure level and near end signal predicted, and for generating echo cancellor output letter
Number.
2. it is used for the system of echo cancellor as described in claim 1, further include loud speaker and the near end signal is provided
Microphone, the loud speaker are coupled to the amplifier output of the current/voltage sensing amplifier.
3. it is used for the system of echo cancellor as claimed in claim 2, wherein, the dynamic loudspeaker management module includes dynamic
Loud speaker manages control block and loud speaker modeling device.
4. as claimed in claim 3 be used for echo cancellor system, wherein, the loud speaker modeling device using the electric current/
The voltage parameter output of voltage sense amplifier and current parameters output, to generate resonant frequency (Fc) parameter and total
Quality factor (Q) parameter as the dynamic loudspeaker management module parameter export.
5. as claimed in claim 4 be used for echo cancellor system, wherein, the loud speaker modeling device using the electric current/
The voltage parameter output of voltage sense amplifier and current parameters output, to generate d.c. coil resistances (Rdc) parameter
Parameter as the dynamic loudspeaker management module exports.
6. it is used for the system of echo cancellor as claimed in claim 5, wherein, the voltage parameter output is that the dynamic is raised one's voice
The parameter output of device management module.
7. it is used for the system of echo cancellor as claimed in claim 5, wherein, the output of the dynamic loudspeaker management control block
It is the parameter output of the dynamic loudspeaker management module.
8. it is used for the system of echo cancellor as claimed in claim 3, wherein, the dynamic loudspeaker management control block receives institute
It states remote signaling and is coupled to the current/voltage sensing amplifier, the loud speaker modeling device is configured as from the electricity
Stream/voltage sense amplifier receives the voltage parameter output and current parameters output, the dynamic loudspeaker management control
Each in clamp dog and the loud speaker modeling device is coupled to the sound pressure level model module, and the dynamic loudspeaker
Management control block is coupled to the loud speaker modeling device.
9. a kind of method for echo cancellor, including：
It measures the voltage (V) for the loudspeaker coil for being applied to loud speaker and flows through the electric current (I) of the loudspeaker coil, with generation
Voltage parameter and current parameters；
The impedance of the loudspeaker coil is modeled according to the voltage parameter and the current parameters, it is multiple to provide
Parameter exports；
It is exported using the multiple parameter and is modeled come the sound pressure level of the prediction to being used for the loud speaker；
The sound pressure level predicted is applied to Echo Canceller as reference；And
Near end signal is applied to the Echo Canceller, and
Wherein described Echo Canceller generation echo cancellation output signal.
10. it is used for the method for echo cancellor as claimed in claim 9, wherein, the multiple parameter output includes resonant frequency
(Fc) parameter output and total quality factor (Q) parameter export.
11. it is used for the method for echo cancellor as claimed in claim 10, wherein, the multiple parameter output includes d.c. coils
Resistance (Rdc) parameter output.
12. it is used for the method for echo cancellor as claimed in claim 11, wherein, the multiple parameter is joined including the voltage
Number.
13. it is used for the method for echo cancellor as claimed in claim 11, wherein, the multiple parameter is believed including modified distal end
Number parameter.
Applications Claiming Priority (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US201261721010P | 2012-10-31 | 2012-10-31 | |
| US201261721021P | 2012-10-31 | 2012-10-31 | |
| US201261721015P | 2012-10-31 | 2012-10-31 | |
| US61/721,021 | 2012-10-31 | ||
| US61/721,010 | 2012-10-31 | ||
| US61/721,015 | 2012-10-31 | ||
| US14/067,716 | 2013-10-30 | ||
| US14/067,716 US9344050B2 (en) | 2012-10-31 | 2013-10-30 | Dynamic speaker management with echo cancellation |
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| CN103796135A CN103796135A (en) | 2014-05-14 |
| CN103796135B true CN103796135B (en) | 2018-06-19 |
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| GB2525051B (en) * | 2014-09-30 | 2016-04-13 | Imagination Tech Ltd | Detection of acoustic echo cancellation |
| US9712915B2 (en) * | 2014-11-25 | 2017-07-18 | Knowles Electronics, Llc | Reference microphone for non-linear and time variant echo cancellation |
| CN111916100A (en) * | 2019-05-07 | 2020-11-10 | 北京地平线机器人技术研发有限公司 | Echo cancellation method and apparatus, storage medium, and electronic device |
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| CN1176034A (en) * | 1995-02-24 | 1998-03-11 | 艾利森公司 | Apparatus and method for canceling acoustic echoes including non-linear distortions in loudspeaker telephones |
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