"Aparna Ram" wrote in message
oups.com...

Ron Baker, Pluralitas! wrote:
"Aparna Ram" wrote in message
oups.com...

Ron Baker, Pluralitas! wrote:
"Aparna Ram" wrote in message
ups.com...
Dear all,

I am working on the acoustic echo cancellation.I have

snip

is getting.Yes it is notcancelling the low eigen value echoes.

The LMS has limitations. But you might try reducing
your mu.

Yes even after reducing the mu value I am getting the same type
of behaviour with noise.


So to avoid this eigen value spread now I am working on the
subband LMS algorithm in frequency domain for acoustic echo
cancellation.So now I am searching for the documents of subband LMS
algorithm and frequency domain LMS algorithm in which it is
mentioned
clearly which samples are to be considered and why.

Interesting. What documents do you have now?

I have some thesis papers in which it is not mentioned the details
that I am searching for.

Maybe you should hire an engineer to explain them
to you.


snip


That statement is not clear either but it must be that
you mean that k is the frame or iteration number.

k is the iteration number

OK.

snip

What are you using as the desired signal?

Here the desired signal frequency components are calculated (using
DFT) using all the desired signal samples(in time domain) of the
fullband.

I meant the orginal, in the time domain. But never
mind, I think I know what it is.

Is my idea of desired signal calculation in frequency domain is
correct????

To the extent you are able to describe it I
see no problem.




Step5:Using this error sample in frequency domain all the weights of
the filter are updated using the following formula:

Wk+1(i) = Wk(i) + 2 * muk * Ek * Xk

snip

What is 'i'? It doesn't seem to fit.
i varies from 0 to (number of weights of the filter - 1).

Then Ek, Xk, and even muk should have i as an
index too. Ek(i) Xk(i) and maybe muk(i)

k is not the frame number.It is the iteration number.

And as I stated, in my view they should be
more or less the same thing.

And 'i' should appear in the other places I mentioned
in the equation.

snip

Nothing? All zeros? It crashes?

Yes Mr.Ron Baker I am getting zeros.But not all zeros.Initially I
am
getting some values and then it is decreased to zeros and ther
after I
am getting all zeros.But why we will get zeros? and why it
crashes???

Hard to tell from what you've been able to say.

I mean to say that after converting the error samples of a
frame from frequency domain to time domain(which may be or
maynot be a complex number and after converting that totally
to a real number) I am getting very very less values and
gradually it is decreased to zero.

Maybe you have the sign of Ek inverted.
In any case, it is hardly practical to debug your
code via this forum.

--
rb