A Variable Bandwidth Filter for Estimation of Instantaneous Frequency and Reconstruction of Signals With Time-Varying Spectral Content

作者：Lee Heyoung^*; Bien Zeungnam ''Zenn''

来源：IEEE Transactions on Signal Processing, 2011, 59(5): 2052-2071.

DOI：10.1109/TSP.2011.2113345

• Decomposition of multicomponent signal
• estimation of instantaneous frequency
• heterogeneous time-frequency (TF) distribution
• spectral localization
• time-varying spectral content
• variable bandwidth filter (VBF)

The notion of "instantaneous frequency" is utilized in processing signals with time-varying spectral content. Specifically, a variable bandwidth filter (VBF) and some related spectral analysis tools are proposed to handle a multicomponent signal whose components interact with each other in the time-frequency (TF) domain. In the analysis, a multicomponent signal is decomposed into its components by estimating local instantaneous frequencies (IFs). In order to construct the proposed filter, we define a differential operator composed of the derivative operator and a positive time-varying coefficient. An extended Fourier transform (EFT) and its functional relations are derived to exploit the newly defined differential operator and the VBF in some weighted vector spaces. Further, a heterogeneous TF distribution is constructed by a short-time EFT to utilize as a criterion for identifying whether an estimated IF is intrinsic or not and repairing a suspect estimate of IF. To confirm usefulness of the EFT and the VBF, we conduct several numerical simulations for spectral localization of an AM-FM signal and for estimation of local IFs, and then, for decomposition of a multicomponent signal into its components with their resolving powers to be compared.

• 出版日期2011-5