use matlab to do short time fourier transform

Hi all the experts,

I would like to use Matlab to do short time fourier transform on a speech
signal. May I know how can I use the windowing function and fft function to
do the short time fourier transform? (I know there is a blockset to do that
but I'm not allowed to use simlink to do the short time fourier transform.
So please help!

Thank alot.

David

That would be called "Homework"?

If you are looking for help with the easy questions you can rest assured
that there is little you will ever learn.

Try looking it up.

You are quite welcome.

Dirk

Dirk A. Bell
DSP Consultant


"David" <april29@singnet.com> wrote in message
news:bf2g7e$u84$1@mawar.singnet.com.sg...
> Hi all the experts,
>
> I would like to use Matlab to do short time fourier transform on a speech
> signal. May I know how can I use the windowing function and fft function
to
> do the short time fourier transform? (I know there is a blockset to do
that
> but I'm not allowed to use simlink to do the short time fourier transform.
> So please help!
>
> Thank alot.
>
> David
>
>

"Dirk Bell" <dirkman@erols.com> wrote in message
news:bf2joc$nju$1@bob.news.rcn.net...
>
> Try looking it up.
>

thanks dirk....

if ur using MATLAB, try using the help files.  type help hanning for
windows, and instructions on how to use the command will appear.  try doing
this for FFT too, a list will appear, and other commands taht might come in
useful will be there (fftshift etc).

most of these commands are easy to implement:

fftsignal = fft (x)  % performs the fft on a signal x, which usualy has a
length of N samples.  (MATLAB works with discrete vaules)

and:

windowed = hanning(fftsignal) % windows the fft-ed signal.

quite easy to do, and MATLAB is a language that is easy to pick up.

search around on google, and look for some source code from which to
deconstruct, learn and understand, and then put it back the way you think
the program will work for.

try looking in the MATLAB newsgroup, that should provide you with more help,
but i strongly reccomend looking in the help files that come with MATLAB, as
this can solve a lot of your problems, and avoid being critised on here for
not having looked in the first place!

HTH

phil

Phil,

I just think coming here for a solution should not be the first thing
someone does when given a problem, especially for homework. Most people are
here to help, not do the work for others. It is also a shame that he
apparently is using Simulink blocksets with no grasp as to what he is doing,
and apparently has no interest in learning. If he can't start MATLAB and
find 'Help' for obvious topics without help ...

Dirk

"Phil Newman" <phillenium2002@hotmail.com> wrote in message
news:bf3r0l$5td$1@news8.svr.pol.co.uk...
>
> "Dirk Bell" <dirkman@erols.com> wrote in message
> news:bf2joc$nju$1@bob.news.rcn.net...
> >
> > Try looking it up.
> >
>
> thanks dirk....
>
> if ur using MATLAB, try using the help files.  type help hanning for
> windows, and instructions on how to use the command will appear.  try
doing
> this for FFT too, a list will appear, and other commands taht might come
in
> useful will be there (fftshift etc).
>
> most of these commands are easy to implement:
>
> fftsignal = fft (x)  % performs the fft on a signal x, which usualy has a
> length of N samples.  (MATLAB works with discrete vaules)
>
> and:
>
> windowed = hanning(fftsignal) % windows the fft-ed signal.
>
> quite easy to do, and MATLAB is a language that is easy to pick up.
>
> search around on google, and look for some source code from which to
> deconstruct, learn and understand, and then put it back the way you think
> the program will work for.
>
> try looking in the MATLAB newsgroup, that should provide you with more
help,
> but i strongly reccomend looking in the help files that come with MATLAB,
as
> this can solve a lot of your problems, and avoid being critised on here
for
> not having looked in the first place!
>
> HTH
>
> phil
>
>

"Dirk Bell" <dirkman@erols.com> wrote in message
news:bf46mv$lrq$1@bob.news.rcn.net...
> Phil,
>
> I just think coming here for a solution should not be the first thing
> someone does when given a problem, especially for homework. Most people
are
> here to help, not do the work for others. It is also a shame that he
> apparently is using Simulink blocksets with no grasp as to what he is
doing,
> and apparently has no interest in learning. If he can't start MATLAB and
> find 'Help' for obvious topics without help ...
>
> Dirk
>
>
fair enough, but i've been on the receiving end of that before, and it's
quite frustrating! I didnt give him the full solution, merely a guide, and
where to find some information. any program language is dificult to learn
straight off, but hopefully, he shall gain the basics from here and build on
it. just wish he'd acknowledge my help :o(

phil

ps i dont know how to use simulink - doesn't mean i dont know something
about DSP