[linux-audio-dev] jamin and FFT filtering

[Alfons Adriaensen]

On Wed, Aug 11, 2004 at 03:58:40PM +0100, Steve Harris wrote:

> In the meantime I'l try it with vanilla raised cosines.

I don't think this will work. There's a condition on the window
shape: if you add up all the time-shifted overlapping windows
the result must be a constant, otherwise you introduce AM.

If you do the raised cosine twice, this condition is not
satisfied. The 8x overlap will mitigate the effect, but
I don't think is usable.

The nice thing about SRRC is that if you do it twice, the
result is a raised cosine, and that will combine perfectly
with the next an previous ones if they are half an FFT length
apart. So any 2n overlap will work.

-- 
FA