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Discussion Groups | Echo Cancellation | RE: Acoustic echo simulator
Acoustic echo simulator - panandh74 - Jun 10 21:01:00 2004
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Hi all, I'm working on acoustic echo cancellation. I need help in simulating acoustic echo. Can somebody give me any site or suggestions? Anandh. |
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RE: Acoustic echo simulator - Vladan Bajic - Jun 11 15:28:00 2004
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Hi Anandh, Try http://www.esat.kuleuven.ac.be/~rombouts/demo/aec.html or http://www.ee.ucla.edu/~dsplab/index.html There is a lot of them on the web. Hope it helps. Vladan -----Original Message----- From: panandh74 [mailto:] Sent: Thursday, June 10, 2004 5:01 PM To: Subject: [echocancel] Acoustic echo simulator Hi all, I'm working on acoustic echo cancellation. I need help in simulating acoustic echo. Can somebody give me any site or suggestions? Anandh. ------------------------ Yahoo! Groups Sponsor --------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/sVPplB/TM --------------------------------------------------------------------~-> _____________________________________ Yahoo! Groups Links |
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Re: Acoustic echo simulator - bojuchen2000 - Jul 6 16:46:00 2004
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Hi: I have a question. What is the difference between acoustic echo cancellation and G.168? Are they the same? BJC --- In , "Vladan Bajic" <vbajic@a...> wrote: > Hi Anandh, > Try http://www.esat.kuleuven.ac.be/~rombouts/demo/aec.html or > http://www.ee.ucla.edu/~dsplab/index.html > There is a lot of them on the web. Hope it helps. > Vladan > > -----Original Message----- > From: panandh74 [mailto:panandh74@y...] > Sent: Thursday, June 10, 2004 5:01 PM > To: > Subject: [echocancel] Acoustic echo simulator > > Hi all, > > I'm working on acoustic echo cancellation. I need help in simulating > acoustic echo. Can somebody give me any site or suggestions? > > Anandh. > ------------------------ Yahoo! Groups Sponsor -------------------- ~--> > Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. > Now with Pop-Up Blocker. Get it for free! > http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/sVPplB/TM > ------------------------------------------------------------------- -~-> > > _____________________________________ > Yahoo! Groups Links |
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RE: Re: Acoustic echo simulator - Saraj - Jul 7 4:29:00 2004
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BJC, G.168 is ITU Recommnedation for Line Echo Cancellation while for Acoustic Echo Cancellation it is G.167. Regards, -Saraj -----Original Message----- From: bojuchen2000 [mailto:] Sent: Tuesday, July 06, 2004 10:16 PM To: Subject: [echocancel] Re: Acoustic echo simulator Hi: I have a question. What is the difference between acoustic echo cancellation and G.168? Are they the same? BJC --- In , "Vladan Bajic" <vbajic@a...> wrote: > Hi Anandh, > Try http://www.esat.kuleuven.ac.be/~rombouts/demo/aec.html or > http://www.ee.ucla.edu/~dsplab/index.html > There is a lot of them on the web. Hope it helps. > Vladan > > -----Original Message----- > From: panandh74 [mailto:panandh74@y...] > Sent: Thursday, June 10, 2004 5:01 PM > To: > Subject: [echocancel] Acoustic echo simulator > > Hi all, > > I'm working on acoustic echo cancellation. I need help in simulating > acoustic echo. Can somebody give me any site or suggestions? > > Anandh. > ------------------------ Yahoo! Groups Sponsor -------------------- ~--> > Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. > Now with Pop-Up Blocker. Get it for free! > http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/sVPplB/TM > ------------------------------------------------------------------- -~-> > > _____________________________________ > Yahoo! Groups Links _____________________________________ Yahoo! Groups Links |
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Re: Re: Acoustic echo simulator - Manish Bajpai - Jul 7 6:57:00 2004
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G.168 talks about Network echo cancellation. It is different
from acoustic EC. As far as I know, there is no ITU-T standard for accoustic echo. However, the
test framework suggested in G.168 can be used to test an accoust EC also. Please note that the
standard does not give much information about the implementation of the network
EC.
Accoustic EC is more difficult to implement because longer
delayes involved (of the order of 128ms or more). This calls for adaptive algorithms which are
more efficient. One popular technique is subband filtering. You can search for the research
paper:
"Residual Echo Signal in Critically Sampled Subband Acoustic Echo Cancellers Based on IIR and FIR Filter Banks" This paper has a very good discuussion on AEC.
Cheers, Manish
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Re: Re: Acoustic echo simulator - L. Hao - Jul 7 7:00:00 2004
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If my memory serves me right, acoustic echo cancellation is defined in G.167. bojuchen2000 <n...@ms94.url.com.tw> wrote: Hi: ----------------------------------------------------------------------- Li Hao h...@yahoo.com __________________________________________________ |
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Re: Acoustic echo simulator - bojuchen2000 - Jul 8 16:05:00 2004
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Manish: Thanks for your explanation about my question. i'm going to have a project about line echo cancellation. The documentation i have is only G.168. Could you have any documentation, book or paper that tells more details about line EC? Any suggestion is welcome. BJC --- In , "Manish Bajpai" <manish_bajpai@i...> wrote: > G.168 talks about Network echo cancellation. It is different from acoustic EC. As far as I know, there is no ITU-T standard for accoustic echo. However, the test framework suggested in G.168 can be used to test an accoust EC also. Please note that the standard does not give much information about the implementation of the network EC. > > Accoustic EC is more difficult to implement because longer delayes involved (of the order of 128ms or more). This calls for adaptive algorithms which are more efficient. One popular technique is subband filtering. You can search for the research paper: > "Residual Echo Signal in Critically Sampled Subband Acoustic Echo Cancellers Based on IIR and FIR Filter Banks" > > This paper has a very good discuussion on AEC. > > Cheers, > > Manish > > ----- Original Message ----- > From: bojuchen2000 > To: > Sent: Tuesday, July 06, 2004 10:16 PM > Subject: [echocancel] Re: Acoustic echo simulator > Hi: > I have a question. > What is the difference between acoustic echo cancellation and G.168? > Are they the same? > BJC > --- In , "Vladan Bajic" <vbajic@a...> > wrote: > > Hi Anandh, > > Try http://www.esat.kuleuven.ac.be/~rombouts/demo/aec.html or > > http://www.ee.ucla.edu/~dsplab/index.html > > There is a lot of them on the web. Hope it helps. > > Vladan > > > > -----Original Message----- > > From: panandh74 [mailto:panandh74@y...] > > Sent: Thursday, June 10, 2004 5:01 PM > > To: > > Subject: [echocancel] Acoustic echo simulator > > > > Hi all, > > > > I'm working on acoustic echo cancellation. I need help in > simulating > > acoustic echo. Can somebody give me any site or suggestions? > > > > Anandh. > > > |
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Re: Re: Acoustic echo simulator - Manish Bajpai - Jul 9 7:04:00 2004
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HI BJC,
There are a couple of sources you can refer to depending on
what your project exactly demands from you.
On the theory of Adaptive Signal Processing, there is an
excellent book by Simon Haykin named Adaptive Filter Theory (Third Ed) brought out by Prentice
Hall.
There are a couple of Applicaion Notes by TI and a couple of
good research papers by Bell-labs which are freely available over the net.
Digital Signal Processing Solutions September 1996 SPRA322 By TI is good to begin with, but not very good if you want to implement a commercial grade EC. A good paper which talks about AEC but is equally good in situations where LEC needs to support higher tail lenghts like 64-256 ms is: "Residual Echo Signal in Critically Sampled Subband Acoustic Echo Cancellers Based on IIR and FIR Filter Banks" On Subband Decomposition and Multirate PP Vaidyanathan has written a classic named "Multirate systems and filter banks" If you search on the net, you will get a couple of open source EC implementations which are nothing but copy of various TI app notes. These will give you good idea. Cheers Manish
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