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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Acoustic echo simulator
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 --------------------------------~-> _____________________________________ Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. You need to do a "reply all" if you want your answer to be distributed to the entire group. _____________________________________ About this discussion group: To Join: To Post: To Leave: Archives: http://www.yahoogroups.com/group/echocancel Other DSP-Related Groups: http://www.dsprelated.com Yahoo! Groups Links |
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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 > ------------------------------- -~-> > > _____________________________________ > Note: If you do a simple "reply" with your email client, only the author > of this message will receive your answer. You need to do a "reply all" > if you want your answer to be distributed to the entire group. > > _____________________________________ > About this discussion group: > > To Join: > > To Post: > > To Leave: > > Archives: http://www.yahoogroups.com/group/echocancel > > Other DSP-Related Groups: http://www.dsprelated.com > > Yahoo! Groups Links |
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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 > ------------------------------- -~-> > > _____________________________________ > Note: If you do a simple "reply" with your email client, only the author > of this message will receive your answer. You need to do a "reply all" > if you want your answer to be distributed to the entire group. > > _____________________________________ > About this discussion group: > > To Join: > > To Post: > > To Leave: > > Archives: http://www.yahoogroups.com/group/echocancel > > Other DSP-Related Groups: http://www.dsprelated.com > > Yahoo! Groups Links _____________________________________ Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. You need to do a "reply all" if you want your answer to be distributed to the entire group. _____________________________________ About this discussion group: To Join: To Post: To Leave: Archives: http://www.yahoogroups.com/group/echocancel Other DSP-Related Groups: http://www.dsprelated.com Yahoo! Groups Links |
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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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 __________________________________________________ |
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. > > > > |
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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