This paper introduces the concept of product function frames. These frames
are a collection of sequences, or frame kernels, that are represented as pr
oducts of two or more sequences. This forms a generalized structure for man
y of the currently existing transforms. We define the conditions on the fra
me and dual frame kernels for the space of periodic discrete-time sequences
. We then derive windowed transforms, modulated filterbanks, and oversample
d filterbanks as special cases. Finally, we introduce a new family of trans
forms, which we call 'product transforms'. (C) 2000 Published by Elsevier S
cience B.V. All rights reserved.