Concept

Analogique

Publications associées (385)

How to take advantage of aliasing in bandlimited signals

Martin Vetterli, Luciano Sbaiz, Patrick Vandewalle

In signal processing systems, aliasing is normally treated as a disturbing signal. That motivates the need for effective analog, optical and digital anti-aliasing filters. However, aliasing conveys also valuable information on the signal above the Nyquist ...

2004

A simple test to check the optimality of a sparse signal approximation

Pierre Vandergheynst, Rémi Gribonval

Approximating a signal or an image with a sparse linear expansion from an overcomplete dictionary of atoms is an extremely useful tool to solve many signal processing problems. Finding the sparsest approximation of a signal from an arbitrary dictionary is ...

2004

Hyper-Rayleigh scattering of gold nanorods and their relationship with linear assemblies of gold nanospheres

Hubert Girault, Pierre-François Marie Brevet, Jean-Pierre Abid

The surface plasmon enhanced hyper-Rayleigh scattering light collected from an aqueous solution of gold nanorods is reported. A non negligible part of the signal is attributed to a photoluminescence background attributed to the electron–hole recombination ...

2004

High-precision DAC based on a self-calibrated sub-binary radix converter

Maher Kayal, Marc Pastre

A novel DAC architecture based on a sub-binary radix converter is presented. By calibrating digitally the nonlinear sub-binary converter, it is possible to use it as a high-precision, high-resolution digital-to-analog converter. The analog part of the new ...

2004

On the Use of A Priori Information for Sparse Signal Representations

Pierre Vandergheynst, Lorenzo Granai, Oscar Divorra Escoda

This report studies the effect of introducing a priori knowledge to recover sparse representations when overcomplete dictionaries are used. We focus mainly on Greedy algorithms and Basis Pursuit as for our algorithmic basement, while a priori is incorporat ...

2004

On the Use of A Priori Information for Sparse Signal Approximations

Pierre Vandergheynst, Lorenzo Granai, Oscar Divorra Escoda

This report is the extension to the case of sparse approximations of our previous study on the effects of introducing a priori knowledge to solve the recovery of sparse representations when overcomplete dictionaries are used. Greedy algorithms and Basis Pu ...

2004

Adaptive MIMO OFDM Receivers: Implementation Impairments and Complexity Issues

Ali H. Sayed

MIMO OFDM communications is a promising choice for future high data rate wireless systems. However, the commercial deployment of MIMO OFDM systems faces some challenges, including those arising from front-end analog implementation impairments and complex ...

2004

Generation of high-quality signals for optical sensing using DFB lasers injection locking

Luc Thévenaz, Dario Alasia

Injection locking of two DFB semiconductors opens new possibilities to generate effective signals for optical sensing, in order to reach better performances. Pure waveforms can be generated with qualities exceeding those obtained using external modulators. ...

International Society for Optical Engineering, Bellingham, WA 98227-0010, United States2004

Volume holographic grating-based continuously tunable optical filter

Demetri Psaltis, Wei Liu

We propose and demonstrate a widely tunable optical filter, realized by angle tuning a volume holographic grating. The volume holographic grating selectively drops a narrow portion of the signal bandwidth into a fiber while passing through the rest of the ...

2004

The distributed Karhunen-Loeve transform

Martin Vetterli, Michael Christoph Gastpar, Pier Luigi Dragotti

The Karhunen-Loeve transform (KLT) is a key element of many signal processing tasks, including approximation, compression, and classification. Many recent applications involve {\em distributed} signal processing where it is not generally possible to apply ...

2003

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