This article proposes an efficient two-channel time delay estimation method for tracking a moving speaker in noisy and re-verberant environment. Unlike conventional linear regression model-based methods, the proposed multiple linear regression model designed in the expanded phase domain shows high estimation accuracy in adverse condition because its the Gaussian assumption on phase distribution...

It is well known that the convergence (with different speeds) of the matching pursuit (MP) signal decomposition algorithm for any dense dictionary is guaranteed. In this paper, we have analysed (in theory and through simulations) the performance and properties of both Gaussian and damped sinusoidal atoms for the MP signal decomposition. We have examined the decomposed signal in ambiguity space ...

The peak of the polynomial Wigner-Ville distribution is known to be a consistent estimator of the instantaneous frequency for polynomial FM signals. In this paper, we present an algorithm for the design of an optimal time-varying window length for this estimator when noisy non-linear, not necessarily polynomial, FM signals are considered. The results obtained show that the estimator is accurate...

In the past, when patients were taking computed tomography (CT) scan, the physician usually monitored the patients on-site as a passive way; however, the entire physiological conditions of the patients couldn’t be fully comprehended this way. According to many clinical reports, the heart rates of the patients under tomography may fluctuate because of the injection of contrast medium. A standard...

There are many methods able to extract the instantaneous frequencies from a time series for practical applications. Gabor’s method is one of the most popular and simple methods. For wide band time series, Gabor’s method may produce negative frequencies. The limitation of Gabor’s method is that, in order to avoid resulting with negative frequencies, it can only be applied to time series with mon...

The response of many dynamical systems to an impulse is a linear combination of decaying cosines. The frequencies of the cosines have generally been estimated in geophysics by periodogram analysis and little formal indication of uncertainty has been provided. This work presents an estimation procedure by the methods of complex demodulation and nonlinear regression that specifically incorporates...

In the last years several laboratories actively work on construction of X-ray free electron lasers (XFEL) with wavelength of radiation of the order λ ~ 0.1 nm. Theoretical calculations show, that self-induced amplification of spontaneous radiation on the exit of an XFEL undulator forms a pulse composed of many ultra-short peaks with duration from a fraction up to tens femtosecond. A further tai...

Estimation of the instantaneous frequency and its derivatives is considered for a harmonic signal with a time-varying phase and time-invariant amplitude. The asymptotic minimax lower bound is derived for the mean squared error of estimation provided that the phase is an arbitrary m-times piece-wise differentiable function of time. It is shown that this lower bound is different only in a constan...