Abstract
We present an example of a positive function g with a positive Fourier transform <i and reasonable smoothness and decay properties such that (-1)nmexp(p'tm)g(t-n), n,m eZ does not constitute a frame for L2(R). We also give counterexamples for the statement that one can tell (in)definiteness of a Weyl-Heisenberg frame operator from (in)deflniteness of its Weyl symbol. Index Terms-Weyl-Heisenberg frame, Zak transform, Weyl symbol.
Original language | English |
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Pages (from-to) | 621-623 |
Number of pages | 3 |
Journal | IEEE Transactions on Information Theory |
Volume | 42 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1996 |