Next |
Prev |
Top
|
JOS Index |
JOS Pubs |
JOS Home |
Search
- Now, we want an
-channel transform with real filters and real
outputs.
- Only eliminate aliasing between adjacent bands.
Bandpass filters used in practice attenuate noise about
, so
neglected bands are not much of a concern.
- First, design a lowpass prototype window,
, with length
- The lowpass design is constrained to give aliasing
cancellation in neighboring subbands:
- The filter bank analysis filters
are cosine modulations of
:
, where the phases are restricted according to
again for aliasing cancellation.
- Since it is an orthogonal filter bank, the synthesis filters
are simply the time reverse of the analysis filters:
- This filter bank is used in MPEG audio, layers I,II.
- N=32 bands
- M=512 taps (L=8)
Next |
Prev |
Top
|
JOS Index |
JOS Pubs |
JOS Home |
Search
Download JFB.pdf
Download JFB_2up.pdf
Download JFB_4up.pdf
[Comment on this page via email]