As the useful time-frequency tool, the Fractional Fourier Transform (FRFT) and the Short Time Fourier Transform (STFT) have a great development of signal recognition. And the Reduced Fractional Fourier Transform (RFRFT) was recently proposed and has been used in the recognition and estimation of chirp signals. A new method based on STFT and RFRFT is presented for radar signals modulation recogn...

Power Spectral Density (PSD) computed by taking the Fourier transform of auto-correlation functions (WienerKhintchine Theorem) gives better result, in case of noisy data, as compared to the Periodogram approach. However, the computational complexity of Wiener-Khintchine approach is more than that of the Periodogram approach. For the computation of short time Fourier transform (STFT), this probl...

Recently, a direct method of the time–frequency approach, called signal separation operator (SSO), which is based on sinusoidal approximation, was introduced to solving inverse problem multicomponent separation. In very recent paper “Direct via extraction local frequencies with adaptive time-varying parameters”, authors obtained more accurate component recovery formula derived from linear chirp...

In this paper, we develop and evaluate speech enhancement algorithms, which are based on supergaussian generalized autoregressive conditional heteroscedasticity (GARCH) models in the short-time Fourier transform (STFT) domain. We consider three different statistical models, two fidelity criteria, and two approaches for the estimation of the variances of the STFT coefficients. The statistical mo...

The short-time Fourier transform (STFT) and the continuous wavelet transform (CWT) are used to analyze the time course of cellular motion in the inner ear. The velocity responses of individual outer hair cells and Hensen’s cells to sinusoidal and amplitude modulated (AM) acoustical signals applied at the ear canal display characteristics typical of nonlinear systems, including the generation of...

Most speech enhancement algorithms make use of the short-time Fourier transform (STFT), which is a simple and flexible time-frequency decomposition that estimates the short-time spectrum of a signal. However, the duration of short STFT frames are inherently limited by the nonstationarity of speech signals. The main contribution of this paper is a demonstration of speech enhancement and automati...

This paper addresses the problems of blind channel identification and multichannel equalization for speech dereverberation and noise reduction. The time-domain cross-relation method is not suitable for blind room impulse response identification, due to the near-common zeros of the long impulse responses. We extend the cross-relation method to the short-time Fourier transform (STFT) domain, in w...

In this article, we derive the constraints which a set of complex numbers must verify to be a consistent STFT spectrogram, i.e., to be the STFT spectrogram of an actual real-valued signal, and describe how they lead to an objective function measuring the consistency of a set of complex numbers as a spectrogram. We then present a flexible phase reconstruction algorithm based on a local approxima...

An interference excision algorithm in direct-sequence spread spectrum (DS-SS) communication systems is introduced. The proposed excision algorithm is developed for linear frequency modulated (LFM) signals that have broadband frequency characteristics. It is based on the time-frequency analysis of received signals employing short-time Fourier transformation (STFT). To analyze the interference, S...