In this paper, we study the stability of Gabor frames ฯ mb na m n โ Z . We show that ฯ mb na m n โ Z remains a frame under a small perturbation of ฯ m, or n. Our results improve some results from Favier and Zalik and are applicable to many frequently used Gabor frames. In particular, we study the ca
Density of Gabor Frames
โ Scribed by Ole Christensen; Baiqiao Deng; Christopher Heil
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 125 KB
- Volume
- 7
- Category
- Article
- ISSN
- 1063-5203
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โฆ Synopsis
A Gabor system is a set of time-frequency shifts S(g, ) = {e 2ฯibx g(xa)} (a,b)โ of a function g โ L 2 (R d ). We prove that if a finite union of Gabor systems r k=1 S(g k , k ) forms a frame for L 2 (R d ) then the lower and upper Beurling densities of = r k=1 k satisfy D -( ) โฅ 1 and D + ( ) < โ. This extends recent work of Ramanathan and Steger. Additionally, we prove the conjecture that no collection r k=1 {g k (xa)} aโ k of pure translates can form a frame for L 2 (R d ).
๐ SIMILAR VOLUMES
We show that (g 2 , a, b) is a Gabor frame when a > 0, b > 0, ab < 1, and g 2 (t) = ( 1 2 ฯฮณ ) 1/2 (cosh ฯฮณ t) -1 is a hyperbolic secant with scaling parameter ฮณ > 0. This is accomplished by expressing the Zak transform of g 2 in terms of the Zak transform of the Gaussian g 1 (t) = (2ฮณ ) 1/4 exp(-ฯฮณ
The Gabor scheme is generalized to incorporate several window functions as well as kernels other than the exponential. The properties of the sequence of representation functions are characterized by an approach based on the concept of frames. Utilizing the piecewise Zak transform (PZT), the frame op
We consider two problems involving Gabor frames that have recently received much attention. The first problem concerns the approximation of dual Gabor frames in L 2 (R) by finite-dimensional methods. Utilizing the duality relations for Gabor frames we derive a method to approximate the dual Gabor fr