Topic
Time–frequency analysis
About: Time–frequency analysis is a research topic. Over the lifetime, 5407 publications have been published within this topic receiving 104346 citations.
Papers published on a yearly basis
Papers
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TL;DR: Simulation results show that this algorithm is capable of estimating parameters of multicomponent chirp signals even in the presence of strong intended interference and colored noise.
Abstract: A novel algorithm for parameter estimation of multicomponent chirp signals in complicated noise environment is proposed. By the matching pursuit (MP) algorithm, the signal is decomposed into Gabor atoms which provide sparse information that represents the signal time-frequency signature. The Hough transform (HT) is then directly used to estimate the parameter of chirp components without computing the time-frequency distribution. Simulation results show that this algorithm is capable of estimating parameters of multicomponent chirp signals even in the presence of strong intended interference and colored noise.
36 citations
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TL;DR: This new approach is based on reusing the calculations of the STFT at consecutive time instants, which leads to significant savings in hardware components with respect to fast Fourier transform based STFTs.
Abstract: This brief presents the feedforward short-time Fourier transform (STFT). This new approach is based on reusing the calculations of the STFT at consecutive time instants. This leads to significant savings in hardware components with respect to fast Fourier transform based STFTs. Furthermore, the feedforward STFT does not have the accumulative error of iterative STFT approaches. As a result, the proposed feedforward STFT presents an excellent tradeoff between hardware utilization and performance.
36 citations
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TL;DR: In this article, a transform able to detect the time-frequency evolutions of the components present in the transient signal captured must be applied, in order to optimize the result, a method to calculate the theoretical timefrequency evolution of the stator current components is presented, using only the captured current.
36 citations
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TL;DR: In this article, a detailed study on the energy content of a principal slot harmonic (PSH) in an induction motor operating at variable slip is carried out, and the results show that the energy in the PSH reflects the overall state of the machine under these conditions.
Abstract: A detailed study on the energy content of a principal slot harmonic (PSH) in an induction motor operating at variable slip is carried out. The machine is tested under different faulty conditions, namely, broken rotor bar, mixed eccentricity, and interturn short circuit. The use of a combined time–frequency analysis and particle filtering feature extraction procedure allows tracking the evolution of a PSH under different load profiles and integrating its energy. The proposed fault indicator provides values that are equivalent with the traditional one for stationary operation even in the case of pulsating load. The results show that the energy in the PSH reflects the overall state of the machine under these conditions. Furthermore, procedures to discern the different faults in real applications are proposed.
36 citations
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TL;DR: It is shown that estimation of the nonlinear component improves the MSE performance only when the power ratio of nonlinear to linear components is relatively high, and as the number of crossband filters increases, a lower steady-state MSE may be obtained at the expense of slower convergence.
Abstract: In this paper, we introduce an adaptive algorithm for nonlinear system identification in the short-time Fourier transform (STFT) domain. The adaptive scheme consists of a parallel combination of a linear component, represented by crossband filters between subbands, and a quadratic component, which is modeled by multiplicative cross-terms. We adaptively update the model parameters using the least-mean-square (LMS) algorithm, and derive explicit expressions for the transient and steady-state mean-square error (MSE) in frequency bins for white Gaussian inputs. We show that estimation of the nonlinear component improves the MSE performance only when the power ratio of nonlinear to linear components is relatively high. Furthermore, as the number of crossband filters increases, a lower steady-state MSE may be obtained at the expense of slower convergence. Experimental results support the theoretical derivations.
36 citations