Luis F. Chaparro | University of Pittsburgh (original) (raw)

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Papers by Luis F. Chaparro

Research paper thumbnail of Asynchronous signal processing for brain-computer interfaces

Turkish Journal of Electrical Engineering and Computer Sciences

Research paper thumbnail of Signal Separation In The Wigner Distribution Domain Using Fractional Fourier Transform

Publication in the conference proceedings of EUSIPCO, Barcelona, Spain, 2011

Research paper thumbnail of Asynchronous Bank Of Filters For Sparse Signal Decomposition

Publication in the conference proceedings of EUSIPCO, Marrakech, Morocco, 2013

Research paper thumbnail of Non--Stationary Decomposition Using The Discrete Linear Chirp Transform (Dlct) For Fm Demodulation

Publication in the conference proceedings of EUSIPCO, Marrakech, Morocco, 2013

Research paper thumbnail of Channel Estimation For Fast-Varying Mimo-Ofdm Systems

Publication in the conference proceedings of EUSIPCO, Glasgow, Scotland, 2009

Research paper thumbnail of Evolutionary spectral analysis and the generalized Gabor expansion

1995 International Conference on Acoustics, Speech, and Signal Processing

Research paper thumbnail of A Discrete Fractional Evolutionary Transform

Publication in the conference proceedings of EUSIPCO, Aalborg, Denmark, 2010

Research paper thumbnail of Time-Frequency Based Robust Ofdm Channel Equalization

Publication in the conference proceedings of EUSIPCO, Poznan, Poland, 2007

Research paper thumbnail of Channel Modeling And Estimation For Robust Mc-Ss Systems

Publication in the conference proceedings of EUSIPCO, Antalya, Turkey, 2005

Research paper thumbnail of Adaptive time-varying parametric modeling

Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing

Research paper thumbnail of Sampling and reconstruction of non-bandlimited signals using Slepian functions

2008 16th European Signal Processing Conference, 2008

In this paper, we show that the Whittaker-Shannon (WS) sampling theory can be modified for the re... more In this paper, we show that the Whittaker-Shannon (WS) sampling theory can be modified for the reconstruction of non-bandlimited signals. According to the uncertainty principle, non-bandlimited signals have finite time support and thus are more common in practical application. Prolate spheroidal wave functions also called Slepian functions have finite time support and maximum energy concentration within a given bandwidth, so instead of infinite length sinc functions, we consider Slepian functions. We show that by projecting non-bandlimited signals onto the space represented by an orthonormal Slepian basis the minimum sampling rate can be reduced nearly by half, with no aliasing. Moreover, the reconstruction error is much lower than the one obtained by the WS theory. In some cases, depending on the desired reconstruction accuracy, it is possible to lower the rate even further. Simulations show the efficiency of the Slepian functions in the reconstruction of uniformly or non-uniformly...

Research paper thumbnail of Instantaneous frequency estimation using discrete evolutionary transform for jammer excision

2001 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings (Cat. No.01CH37221)

Research paper thumbnail of A new spreading code for multi-carrier spread spectrum systems

Proceedings of the IEEE 13th Signal Processing and Communications Applications Conference, 2005.

... Systems Seda Senay 1 , Aydın Akan 2 ve Luis F. Chaparro 3 Elektrik-Elektronik Mühendisli˘gi B... more ... Systems Seda Senay 1 , Aydın Akan 2 ve Luis F. Chaparro 3 Elektrik-Elektronik Mühendisli˘gi Bölümü 1 Yeditepe ¨Universitesi, Kayısda˘gı, ˙Istanbul. ssenay@ yeditepe.edu.tr 2 ˙Istanbul ¨Universitesi, 34320, Avcılar, ˙Istanbul. ...

Research paper thumbnail of Evolutionary spectral analysis using a warped Gabor expansion

Acoustics, Speech, and Signal Processing, 1988. ICASSP-88., 1988 International Conference on

Research paper thumbnail of An iterative method for instantaneous frequency estimation

Research paper thumbnail of A Discrete Fractional Gabor Expansion for Time--Frequency Signal Analysis

Research paper thumbnail of A New Spreading Code for Multi-User MC-SS Communication Systems

Research paper thumbnail of Higher order evolutionary spectral analysis

2003 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03).

Research paper thumbnail of Multi-window Gabor expansion for evolutionary spectral analysis

Signal Processing, 1997

... SIGNAL PROCESSING ELS EVIER Signal Processing 63 (1997) 249262 Multiwindow Gabor expansion fo... more ... SIGNAL PROCESSING ELS EVIER Signal Processing 63 (1997) 249262 Multiwindow Gabor expansion for evolutionary spectral analysis Aydin Akan'1, Luis F. Chaparro1 ... Als Anwendung prasentieren wir die Berechnung einer Naherung einer ZeitFrequenzDarstellung. ...

Research paper thumbnail of Evolutionary chirp representation of non-stationary signals via Gabor transform

Signal Processing, 2001

... An analogous representation for a deterministic signal x(n) with a time-varying spectrum can ... more ... An analogous representation for a deterministic signal x(n) with a time-varying spectrum can be defined as (2) where ω k =2πk/K, ie, a sum of time-varying sinusoids at discrete frequencies. Most of the existing time–frequency representations use sinusoidal bases. ...

Research paper thumbnail of Asynchronous signal processing for brain-computer interfaces

Turkish Journal of Electrical Engineering and Computer Sciences

Research paper thumbnail of Signal Separation In The Wigner Distribution Domain Using Fractional Fourier Transform

Publication in the conference proceedings of EUSIPCO, Barcelona, Spain, 2011

Research paper thumbnail of Asynchronous Bank Of Filters For Sparse Signal Decomposition

Publication in the conference proceedings of EUSIPCO, Marrakech, Morocco, 2013

Research paper thumbnail of Non--Stationary Decomposition Using The Discrete Linear Chirp Transform (Dlct) For Fm Demodulation

Publication in the conference proceedings of EUSIPCO, Marrakech, Morocco, 2013

Research paper thumbnail of Channel Estimation For Fast-Varying Mimo-Ofdm Systems

Publication in the conference proceedings of EUSIPCO, Glasgow, Scotland, 2009

Research paper thumbnail of Evolutionary spectral analysis and the generalized Gabor expansion

1995 International Conference on Acoustics, Speech, and Signal Processing

Research paper thumbnail of A Discrete Fractional Evolutionary Transform

Publication in the conference proceedings of EUSIPCO, Aalborg, Denmark, 2010

Research paper thumbnail of Time-Frequency Based Robust Ofdm Channel Equalization

Publication in the conference proceedings of EUSIPCO, Poznan, Poland, 2007

Research paper thumbnail of Channel Modeling And Estimation For Robust Mc-Ss Systems

Publication in the conference proceedings of EUSIPCO, Antalya, Turkey, 2005

Research paper thumbnail of Adaptive time-varying parametric modeling

Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing

Research paper thumbnail of Sampling and reconstruction of non-bandlimited signals using Slepian functions

2008 16th European Signal Processing Conference, 2008

In this paper, we show that the Whittaker-Shannon (WS) sampling theory can be modified for the re... more In this paper, we show that the Whittaker-Shannon (WS) sampling theory can be modified for the reconstruction of non-bandlimited signals. According to the uncertainty principle, non-bandlimited signals have finite time support and thus are more common in practical application. Prolate spheroidal wave functions also called Slepian functions have finite time support and maximum energy concentration within a given bandwidth, so instead of infinite length sinc functions, we consider Slepian functions. We show that by projecting non-bandlimited signals onto the space represented by an orthonormal Slepian basis the minimum sampling rate can be reduced nearly by half, with no aliasing. Moreover, the reconstruction error is much lower than the one obtained by the WS theory. In some cases, depending on the desired reconstruction accuracy, it is possible to lower the rate even further. Simulations show the efficiency of the Slepian functions in the reconstruction of uniformly or non-uniformly...

Research paper thumbnail of Instantaneous frequency estimation using discrete evolutionary transform for jammer excision

2001 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings (Cat. No.01CH37221)

Research paper thumbnail of A new spreading code for multi-carrier spread spectrum systems

Proceedings of the IEEE 13th Signal Processing and Communications Applications Conference, 2005.

... Systems Seda Senay 1 , Aydın Akan 2 ve Luis F. Chaparro 3 Elektrik-Elektronik Mühendisli˘gi B... more ... Systems Seda Senay 1 , Aydın Akan 2 ve Luis F. Chaparro 3 Elektrik-Elektronik Mühendisli˘gi Bölümü 1 Yeditepe ¨Universitesi, Kayısda˘gı, ˙Istanbul. ssenay@ yeditepe.edu.tr 2 ˙Istanbul ¨Universitesi, 34320, Avcılar, ˙Istanbul. ...

Research paper thumbnail of Evolutionary spectral analysis using a warped Gabor expansion

Acoustics, Speech, and Signal Processing, 1988. ICASSP-88., 1988 International Conference on

Research paper thumbnail of An iterative method for instantaneous frequency estimation

Research paper thumbnail of A Discrete Fractional Gabor Expansion for Time--Frequency Signal Analysis

Research paper thumbnail of A New Spreading Code for Multi-User MC-SS Communication Systems

Research paper thumbnail of Higher order evolutionary spectral analysis

2003 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03).

Research paper thumbnail of Multi-window Gabor expansion for evolutionary spectral analysis

Signal Processing, 1997

... SIGNAL PROCESSING ELS EVIER Signal Processing 63 (1997) 249262 Multiwindow Gabor expansion fo... more ... SIGNAL PROCESSING ELS EVIER Signal Processing 63 (1997) 249262 Multiwindow Gabor expansion for evolutionary spectral analysis Aydin Akan'1, Luis F. Chaparro1 ... Als Anwendung prasentieren wir die Berechnung einer Naherung einer ZeitFrequenzDarstellung. ...

Research paper thumbnail of Evolutionary chirp representation of non-stationary signals via Gabor transform

Signal Processing, 2001

... An analogous representation for a deterministic signal x(n) with a time-varying spectrum can ... more ... An analogous representation for a deterministic signal x(n) with a time-varying spectrum can be defined as (2) where ω k =2πk/K, ie, a sum of time-varying sinusoids at discrete frequencies. Most of the existing time–frequency representations use sinusoidal bases. ...