FILTERBANK Apply filterbank
Usage: c=filterbank(f,g,a);
FILTERBANK(f,g,a) applies the filters given in g to the signal
f. Each subband will be subsampled by a factor of a (the
hop-size). In contrast to UFILTERBANK, a can be a vector so the
hop-size can be channel-dependant. If f is a matrix, the
transformation is applied to each column.
The filters g must be a cell-array, where each entry in the cell
array corresponds to an FIR filter.
The output coefficients are stored a cell array. More precisely, the
n'th cell of c, c{m}, is a 2D matrix of size M(n) xW and
containing the output from the m'th channel subsampled at a rate of
a(m). c{m}(n,l) is thus the value of the coefficient for time index
n, frequency index m and signal channel l.
The coefficients c computed from the signal f and the filterbank
with windows g_m are defined by
L-1
c_m(n+1) = sum f(l+1) * g_m (a(m)n-l+1)
l=0
where an-l is computed modulo L.
References:
H. Boelcskei, F. Hlawatsch, and H. G. Feichtinger. Frame-theoretic
analysis of oversampled filter banks. Signal Processing, IEEE
Transactions on, 46(12):3256--3268, 2002.
Url: http://ltfat.github.io/doc/filterbank/filterbank.html
See also: ufilterbank, ifilterbank, pfilt.
Package: ltfat