Applications of Time-Frequency Signal Processing in Wireless Communications and Bioengineering
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Citation: EURASIP Journal on Advances in Signal Processing 2011 2010:879104
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Cross Time-Frequency Analysis of Gastrocnemius Electromyographic Signals in Hypertensive and Nonhypertensive Subjects
The effects of hypertension are chronic and continuous; it affects gait, balance, and fall risk. Therefore, it is desirable to assess gait health across hypertensive and nonhypertensive subjects in order to pr...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:206560 -
High-Resolution Time-Frequency Methods' Performance Analysis
This work evaluates the performance of high-resolution quadratic time-frequency distributions (TFDs) including the ones obtained by the reassignment method, the optimal radially Gaussian kernel method, the t-f...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:806043 -
Spectrally Efficient OFDMA Lattice Structure via Toroidal Waveforms on the Time-Frequency Plane
We investigate the performance of frequency division multiplexed (FDM) signals, where multiple orthogonal Hermite-Gaussian carriers are used to increase the bandwidth efficiency. Multiple Hermite-Gaussian func...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:684097 -
Eigenvectors of the Discrete Fourier Transform Based on the Bilinear Transform
Determining orthonormal eigenvectors of the DFT matrix, which is closer to the samples of Hermite-Gaussian functions, is crucial in the definition of the discrete fractional Fourier transform. In this work, we...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:191085 -
Time-Frequency Characterization of Cerebral Hemodynamics of Migraine Sufferers as Assessed by NIRS Signals
Near-infrared spectroscopy (NIRS) is a noninvasive system for the real-time monitoring of the concentration of oxygenated ( ) and reduced...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:459213 -
A New LFM-Signal Detector Based on Fractional Fourier Transform
A new LFM-signal detector formulated by the integration of the 4th-power modulus of the fractional Fourier transform is proposed. It has similar performance to the modulus square detector of Radon-ambiguity tr...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:876282 -
Estimation of Time-Varying Coherence and Its Application in Understanding Brain Functional Connectivity
Time-varying coherence is a powerful tool for revealing functional dynamics between different regions in the brain. In this paper, we address ways of estimating evolutionary spectrum and coherence using the ge...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:390910 -
A Human Gait Classification Method Based on Radar Doppler Spectrograms
An image classification technique, which has recently been introduced for visual pattern recognition, is successfully applied for human gait classification based on radar Doppler signatures depicted in the tim...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:389716 -
Signal Reconstruction from Nonuniformly Spaced Samples Using Evolutionary Slepian Transform-Based POCS
We consider the reconstruction of signals from nonuniformly spaced samples using a projection onto convex sets (POCSs) implemented with the evolutionary time-frequency transform. Signals of practical interest ...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:367317 -
The Spread of a Noise Field in a Dispersive Medium
We discuss the production of induced noise by a pulse and the propagation of the noise in a dispersive medium. We present a simple model where the noise is the sum of pulses and where the mean of each pulse is...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:484753 -
Noise and Speckle Reduction in Doppler Blood Flow Spectrograms Using an Adaptive Pulse-Coupled Neural Network
A novel method, called adaptive pulse coupled neural network (AD-PCNN) using a two-stage denoising strategy, is proposed to reduce noise and speckle in the spectrograms of Doppler blood flow signals. AD-PCNN c...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:918015 -
Time-Frequency Based Channel Estimation for High-Mobility OFDM Systems–Part I: MIMO Case
Multiple-input multiple-output (MIMO) systems hold the potential to drastically improve the spectral efficiency and link reliability in future wireless communications systems. A particularly promising candidat...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:549197 -
Optimization of Weighting Factors for Multiple Window Spectrogram of Event-Related Potentials
This paper concerns the mean square error optimal weighting factors for multiple window spectrogram of different stationary and nonstationary processes. It is well known that the choice of multiple windows is ...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:391798 -
Synchronization between EMG at Different Uterine Locations Investigated Using Time-Frequency Ridge Reconstruction: Comparison of Pregnancy and Labor Contractions
The extraction of the frequency components of a signal can be useful for the characterization of the underlying system. One method for isolating a frequency component of a signal is by the extraction and recon...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:242493 -
Time-Frequency Based Channel Estimation for High-Mobility OFDM Systems—Part II: Cooperative Relaying Case
We consider the estimation of time-varying channels for Cooperative Orthogonal Frequency Division Multiplexing (CO-OFDM) systems. In the next generation mobile wireless communication systems, significant Doppl...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:973286 -
Interactions between Uterine EMG at Different Sites Investigated Using Wavelet Analysis: Comparison of Pregnancy and Labor Contractions
This paper describes the use of the Morlet wavelet transform to investigate the difference in the time-frequency plane between uterine EMG signals recorded simultaneously on two different sites on women's abdo...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:918012 -
Time-Frequency Data Reduction for Event Related Potentials: Combining Principal Component Analysis and Matching Pursuit
Joint time-frequency representations offer a rich representation of event related potentials (ERPs) that cannot be obtained through individual time or frequency domain analysis. This representation, however, c...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:289571 -
Approximating the Time-Frequency Representation of Biosignals with Chirplets
A new member of the Cohen's class time-frequency distribution is proposed. The kernel function is determined adaptively based on the signal of interest. The kernel preserves the chirp-like components while rem...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:857685 -
Time-Frequency Analysis and Hermite Projection Method Applied to Swallowing Accelerometry Signals
Fast Hermite projections have been often used in image-processing procedures such as image database retrieval, projection filtering, and texture analysis. In this paper, we propose an innovative approach for t...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:323125 -
Wavelength- and Time-Selective Reconfigurable Optical Add/Drop Multiplexer Using Time-Frequency Domain Processing
We propose and demonstrate a wavelength- and time-selective reconfigurable optical add/drop multiplexer (ROADM) using time-frequency domain processing. The proposed ROADM is realized by allocating wavelength c...
Citation: EURASIP Journal on Advances in Signal Processing 2010 2010:807521