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Data-driven atomic decomposition via frequency extraction of intrinsic mode functions. (English) Zbl 1361.94023

Summary: Decomposition of functions in terms of their primary building blocks is one of the most fundamental problems in mathematical analysis and its applications. Indeed, atomic decomposition of functions in the Hardy space \(H^p\) for \(0<p\leq 1\) as infinite series of “atoms” that have the property of vanishing moments with order at least up to \(1/p\) has significant impacts, not only to the advances of harmonic and functional analyses, but also to the birth of wavelet analysis, which in turn allows the construction of sufficiently large dictionaries of wavelet-like basis functions for the success of atomic decomposition of more general functions or signals, by such mathematical tools as “basis pursuit” and “nonlinear basis pursuit”. However, such dictionaries are necessarily huge for atomic decomposition of real-world signals. The spirit of the present paper is to construct the atoms directly from the data, without relying on a large dictionary. Following Gabor, the starting point of this line of thought is to observe that “any” signal \(a\) can be written as \(a(t) = A(t) \cos \phi (t)\) via complex extension using the Hilbert transform. Hence, if a given signal \(f\) has been decomposed by whatever available methods or schemes, as the sum of sub-signals \(f_k\), then each sub-signal can be written as \(f_k(t) = A_k(t) \cos \phi_k(t)\). Whether or not \(f_k\) is an atom of the given signal \(f\) depends on whether any of the sub-signals \(f_k\) can be further decomposed in a meaningful way. In this regard, the most popular decomposition scheme in the current literature is the sifting process of the empirical mode decomposition (EMD), where the sub-signals \(f_k\) are called intrinsic mode functions (IMF’s). The main contribution of our present paper is firstly to demonstrate that IMF’s may not be atoms, and secondly to give a computational scheme for decomposing such IMF’s into finer and meaningful signal building blocks. Our innovation is to apply the signal separation operator (SSO), introduced by the first two authors, with a clever choice of parameters, first to extract the instantaneous frequencies (IF’s) of each IMF obtained from the sifting process, and then (by using the same parameters for the SSO, with the IF’s as input) to construct finer signal building blocks of the IMF. In other words, we replace the Hilbert transform of the EMD scheme by the SSO in this present paper, first for frequency extraction, and then for constructing finer signal building blocks. As an example, we consider the problem in super-resolution of separating two Dirac delta functions that are arbitrarily close to each other. This problem is equivalent to finding the two cosine building blocks of a two-tone signal with frequencies that are arbitrarily close. While the sifting process can only yield one IMF when the frequencies are too close together, the SSO applied to this IMF extracts the two frequencies and recover the two cosine building blocks (or atoms). For this reason, we coin our scheme of sifting + SSO as “superEMD”, where ”super” is used as an abbreviation of super-resolution.

MSC:

94A12 Signal theory (characterization, reconstruction, filtering, etc.)
44A15 Special integral transforms (Legendre, Hilbert, etc.)

Software:

PDCO
Full Text: DOI

References:

[1] Ahlfors, L.V.: Complex Analysis, An Introduction to the Theory of Analytic Functions of One Complex Variable. McGraw-Hill Book Company, New York (1966) · Zbl 0146.29801
[2] Candès, E.J., Fernandez-Granda, C.: Super-resolution from noisy data. J. Fourier Anal. Appl. 19(6), 1229-1254 (2013) · Zbl 1312.94015 · doi:10.1007/s00041-013-9292-3
[3] Candès, E.J., Fernandez-Granda, C.: Towards a mathematical theory of super-resolution. Commun. Pure Appl. Math. 67(6), 906-956 (2014) · Zbl 1350.94011 · doi:10.1002/cpa.21455
[4] Chen, S.S., Donoho, D.L., Saunders, M.A.: Atomic decomposition by basis pursuit. SIAM J. Sci. Comput. 20(1), 33-61 (1998) · Zbl 0919.94002 · doi:10.1137/S1064827596304010
[5] Chui, C.K., Diamond, H.: A general framework for local interpolation. Numer. Math. 58(1), 569-581 (1990) · Zbl 0714.65006 · doi:10.1007/BF01385640
[6] Chui, C.K., Mhaskar, H.N.: Signal decomposition and analysis via extraction of frequencies. Appl. Comput. Harmon. Anal. (2015). doi:10.1016/j.acha.2015.01.003. (in press) · Zbl 1330.94013
[7] Chui, C.K., van der Walt, M.D.: Signal analysis via instantaneous frequency estimation of signal components. Int. J. Geomath. 6(1), 1-42 (2015) · Zbl 1322.94028 · doi:10.1007/s13137-015-0070-z
[8] Chui, C.K., Lin, Y.-T., Wu, H.-T.: Real-time dynamics acquisition from irregular samples—with application to anesthesia evaluation. Anal. Appl. (2015). doi:10.1142/S0219530515500165 · Zbl 1382.94028
[9] Coifman, R.R.: A real variable characterization of \[{H}^p\] Hp. Stud. Math. 3(51), 269-274 (1974) · Zbl 0289.46037
[10] Coifman, R.R., Meyer, Y., Stein, E.M.: Some new function spaces and their applications to harmonic analysis. J. Funct. Anal. 62(2), 304-335 (1985) · Zbl 0569.42016 · doi:10.1016/0022-1236(85)90007-2
[11] Coifman, R.R., Weiss, G., et al.: Extensions of Hardy spaces and their use in analysis. Bull. Am. Math. Soc. 83(4), 569-645 (1977) · Zbl 0358.30023 · doi:10.1090/S0002-9904-1977-14325-5
[12] Daubechies, I.; Maes, S.; Aldroubi, A. (ed.); Unser, MA (ed.), A nonlinear squeezing of the continuous wavelet transform based on auditory nerve models, 527-546 (1996), Boca Raton · Zbl 0848.92003
[13] Daubechies, I., Lu, J., Wu, H.-T.: Synchrosqueezed wavelet transforms: an empirical mode decomposition-like tool. Appl. Comput. Harmon. Anal. 30, 243-261 (2011) · Zbl 1213.42133 · doi:10.1016/j.acha.2010.08.002
[14] Demanet, L., Needell, D., Nguyen, N.: Super-resolution via superset selection and pruning. arXiv:1302.6288 (2013). (arXiv preprint) · Zbl 1322.94028
[15] Donoho, D.L.: Superresolution via sparsity constraints. SIAM J. Math. Anal. 23(5), 1309-1331 (1992) · Zbl 0769.42007 · doi:10.1137/0523074
[16] Gabor, D.: Theory of communication. J. Inst. Elec. Eng. Part III: Radio Commun. Eng. 93(26), 429-441 (1946)
[17] Grafakos, L.: Modern Fourier Analysis, vol. 250. Springer, New York (2009) · Zbl 1158.42001
[18] Hou, T.Y., Shi, Z.: Data-driven time-frequency analysis. Appl. Comput. Harmon. Anal. 35(2), 284-308 (2013a) · Zbl 1336.94019
[19] Hou, T.Y., Shi, Z.: Sparse time-frequency decomposition by adaptive basis pursuit. arXiv:1311.1163 (2013b). (preprint) · Zbl 0919.94002
[20] Huang, N.E., Shen, Z., Long, S.R., Wu, M.C., Shih, H.H., Zheng, Q., Yen, N.-C., Tung, C.C., Liu, H.H.: The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis. Proc. R. Soc. Lond. Ser. A: Math. Phys. Eng. Sci. 454(1971), 903-995 (1998) · Zbl 0945.62093 · doi:10.1098/rspa.1998.0193
[21] Kahane, J.-P.: Turán’s new method and compressive sampling. In: Number Theory, Analysis, and Combinatorics: Proceedings of the Paul Turan Memorial Conference held 22-26 August 2011 in Budapest, p. 155. Walter de Gruyter (2013a) · Zbl 0289.46037
[22] Kahane, J.-P.: Variantes sur un théoreme de candes, romberg et tao. Ann. Inst. Fourier (Grenoble) 63(6), 2081-2096 (2013b) · Zbl 1306.42006
[23] Latter, R.: A characterization of \[{H}^p({R}^n)\] Hp(Rn) in terms of atoms. Stud. Math. 1(62), 93-101 (1978) · Zbl 0398.42017
[24] Stein, E.M., Murphy, T.S.: Harmonic Analysis: Real-Variable Methods, Orthogonality, and Oscillatory Integrals, vol. 3. Princeton University Press, Princeton (1993) · Zbl 0821.42001
[25] Tang, G., Bhaskar, B.N., Recht, B.: Near minimax line spectral estimation. Inf. Theory IEEE Trans. 61(1), 499-512 (2015) · Zbl 1359.94181 · doi:10.1109/TIT.2014.2368122
[26] van der Walt, M.D.: Wavelet analysis of non-stationary signals with applications. Ph.D. thesis, University of Missouri, St. Louis (2015) · Zbl 1350.94011
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