Speex dev - Feb 2006 - NLMS filter length for AEC

Hi all,
   
         I have a query. I developed NLMS acoustic echo cancellation algorithm
for real time voip application and using general purpose processor. Used more
filter length (4096/2048) for NLMS and faced CPU consumption.With less filter
length unable to estimate the exact echo signal and the quality of the speech
also getting degraded.
  Could any one please suggest me the filter length which can give me the better
voice
  quality with echo cancelled? or any other algorithm for AEC better than NLMS
but with
  less complexity?
   
  Thank you.
   
   
   

		
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>        I have a query. I developed NLMS acoustic echo cancellation
> algorithm for real time voip application and using general purpose
> processor. Used more filter length (4096/2048) for NLMS and faced CPU
> consumption.
Normal.
> With less filter length unable to estimate the exact echo signal and
> the quality of the speech also getting degraded.
It probably means you have too much delay between the mic and speaker
signals. 
> Could any one please suggest me the filter length which can give me
> the better voice
> quality with echo cancelled? 
Normally, about 100-200 ms tail length should be enough.
> or any other algorithm for AEC better than NLMS but with
> less complexity?
Speex includes an AEC based on the MDF algorithm with an adaptive
learning rate. Should be much better (and less CPU intensive) than NLMS.

	Jean-Marc