Concept

Fréquence de Nyquist

Publications associées (77)

Subwavelength ultrasonic circulator based on spatiotemporal modulation

Enabling efficient nonreciprocal acoustic devices is challenging, yet very desirable for a variety of applications, including acoustic imaging, underwater communications, energy concentration and harvesting, signal processing,and noise control. We discuss ...

2015

Enhanced response in Brillouin distributed optical fibre sensors by simultaneous time and frequency pump multiplexing

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Li Zhang

A technique to enhance the response of Brillouin distributed sensors is proposed and experimentally validated. The method consists in creating a multi-frequency pump pulse interacting with a multi-frequency continuous-wave probe. The power of each pulse at ...

SPIE2014

Modified parallel code-phase search for acquisition in presence of sign transition

Pierre-André Farine, Cyril Botteron, Jérôme Leclère

One of the method to have a fast acquisition of GNSS signals is the parallel code-phase search, which uses the fast Fourier transform (FFT) to perform the correlation. A problem with this method is the potential sign transition that can happen between two ...

2013

Approaching the Rate-Distortion Limit by spatial Coupling with Belief Propagation and Decimation

Nicolas Macris, Vahid Aref, Marc Vuffray

We investigate an encoding scheme for lossy compression based on spatially coupled Low-Density Generator-Matrix codes. The degree distributions are regular, or are Poisson on the code-bit side and check-regular which allows use for any compression rate. Th ...

2013

Super-resolution from unregistered aliased images with unknown scalings and shifts

Martin Vetterli, Feng Yang

We consider the problem of super-resolution from unregistered aliased images with unknown spatial scaling factors and shifts. Due to the limitation of pixel size in the image sensor, the sampling rate for each image is lower than the Nyquist rate of the sc ...

2012

Design and Exploration of Low-Power Analog to Information Conversion Based on Compressed Sensing

David Atienza Alonso, Pierre Vandergheynst, Nadia Khaled, Hossein Mamaghanian

The long-standing analog-to-digital conversion paradigm based on Shannon/Nyquist sampling has been challenged lately, mostly in situations such as radar and communication signal processing where signal bandwidth is so large that sampling architectures cons ...

2012

One- and two-dimensional UVP velocity sampling in a cuboidal basin subject to in- and outflow sequences

Anton Schleiss, Giovanni De Cesare, Michael Müller

In the framework of an experimental study on the influence of in- and outflow sequences on flow patterns and suspended sediment behavior in reservoirs, flow fields and inflowing jet were sampled by Ultrasonic Velocity Profilers (UVP). The laboratory set-up ...

2012

Sensorcam: An Energy-Efficient Smart Wireless Camera for Environmental Monitoring

Martin Vetterli, Paolo Prandoni, Guillermo Barrenetxea Kobas, Zichong Chen

Reducing energy cost is crucial for energy-constrained smart wireless cameras. Existing platforms impose two main challenges: First, most commercial smart phones have a closed platform, which makes it impossible to manage low-level circuits. Since the samp ...

Assoc Computing Machinery2012

Methods and apparatus for estimating a sparse channel

Martin Vetterli, Ali Hormati, Yann Barbotin

Embodiments include a method for sending a selected number of pilots (20) to a sparse channel having a channel impulse response limited in time comprising sending the selected number of the pilots (20). The pilots (20) are equally spaced in the frequency d ...

USPTO2011

Random Sampling ADC for Sparse Spectrum Sensing

Andreas Peter Burg

Scanning large bandwidths (spectrum sensing) pushes today’s analog hardware to its limits since periodic sampling at Nyquist rate with sufficient resolution is often prohibitively complex. In this paper, we consider a scenario where the signal to be acquir ...

2011

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