newbie filter question

"Pankaj Daga" <pankajdaga@excite.com> wrote in message
news:1a4b2aef.0410150117.67096704@posting.google.com...
> Hi,
>
> There is something that is going on which I failed to notice before.
> It takes the absolute value of the filter bank returned output and
> then does the low pass filtering. What kind of information will that
> provide?

As we suspected.  Absolute value followed by low pass filtering provides some
measure of the average signal energy.  It looks like the process is trying to
find the average energy in different frequency bands.

"Pankaj Daga" <pankajdaga@excite.com> wrote in message
news:1a4b2aef.0410150117.67096704@posting.google.com...
> Hi,
>
> There is something that is going on which I failed to notice before.
> It takes the absolute value of the filter bank returned output and
> then does the low pass filtering. What kind of information will that
> provide?

As we suspected.  Absolute value followed by low pass filtering provides some
measure of the average signal energy.  It looks like the process is trying to
find the average energy in different frequency bands.

Yup,

this must be it! Thanks a lot!!

Best,
N

"Jon Harris" <goldentully@hotmail.com> wrote in message news:<2tad00F1tfk7mU1@uni-berlin.de>...
> "Pankaj Daga" <pankajdaga@excite.com> wrote in message
> news:1a4b2aef.0410150117.67096704@posting.google.com...
> > Hi,
> >
> > There is something that is going on which I failed to notice before.
> > It takes the absolute value of the filter bank returned output and
> > then does the low pass filtering. What kind of information will that
> > provide?
> 
> As we suspected.  Absolute value followed by low pass filtering provides some
> measure of the average signal energy.  It looks like the process is trying to
> find the average energy in different frequency bands.

Pankaj Daga wrote:

> Hi,
> 
> There is something that is going on which I failed to notice before.
> It takes the absolute value of the filter bank returned output and
> then does the low pass filtering. What kind of information will that
> provide?
> 
> Thanks,
> 
> N
-- snip --

That will provide a dandy AM demodulator, assuming that you have 
carriers at 30Hz, 90Hz, etc.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com