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| Autors principals: | , |
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| Format: | Preprint |
| Publicat: |
2000
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| Matèries: | |
| Accés en línia: | https://arxiv.org/abs/math/0010245 |
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| _version_ | 1866912655193669632 |
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| author | Janssen, A. J. E. M Strohmer, Thomas |
| author_facet | Janssen, A. J. E. M Strohmer, Thomas |
| contents | Let $(g_{nm})_{n,m\in Z}$ be a Gabor frame for $L_2(R)$ for given window $g$. We show that the window $h^0=S^{-1/2} g$ that generates the canonically associated tight Gabor frame minimizes $\|g-h\|$ among all windows $h$ generating a normalized tight Gabor frame. We present and prove versions of this result in the time domain, the frequency domain, the time-frequency domain, and the Zak transform domain, where in each domain the canonical $h^0$ is expressed using functional calculus for Gabor frame operators. Furthermore, we derive a Wiener-Levy type theorem for rationally oversampled Gabor frames. Finally, a Newton-type method for a fast numerical calculation of $\ho$ is presented. We analyze the convergence behavior of this method and demonstrate the efficiency of the proposed algorithm by some numerical examples. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_math_0010245 |
| institution | arXiv |
| publishDate | 2000 |
| record_format | arxiv |
| spellingShingle | Characterization and computation of canonical tight windows for Gabor frames Janssen, A. J. E. M Strohmer, Thomas Functional Analysis Numerical Analysis 42C15, 47A60, 94A11, 94A12 Let $(g_{nm})_{n,m\in Z}$ be a Gabor frame for $L_2(R)$ for given window $g$. We show that the window $h^0=S^{-1/2} g$ that generates the canonically associated tight Gabor frame minimizes $\|g-h\|$ among all windows $h$ generating a normalized tight Gabor frame. We present and prove versions of this result in the time domain, the frequency domain, the time-frequency domain, and the Zak transform domain, where in each domain the canonical $h^0$ is expressed using functional calculus for Gabor frame operators. Furthermore, we derive a Wiener-Levy type theorem for rationally oversampled Gabor frames. Finally, a Newton-type method for a fast numerical calculation of $\ho$ is presented. We analyze the convergence behavior of this method and demonstrate the efficiency of the proposed algorithm by some numerical examples. |
| title | Characterization and computation of canonical tight windows for Gabor frames |
| topic | Functional Analysis Numerical Analysis 42C15, 47A60, 94A11, 94A12 |
| url | https://arxiv.org/abs/math/0010245 |