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UMR 5224

Brigitte BidégarayFesquet — Nonuniform signal processing
Partners
LJK 
Brigitte BidégarayFesquet 
TIMA 
Laurent Fesquet, Gilles Sicard, and Taha Beyrouthy,
and formerly Fabien Aeschlimann, Saeed Mian Qaisar 
GipsaLab 
Nicolas Marchand, Christophe Prieur 
Previous work
Most electronic systems have a clock which synchronises everything.
A numerical electronic signal is therefore usually synchronous and corresponds to data at times which are all multiples of a unique sampling time.
Classical signal processing is strongly based on this property.
The CIS team of the TIMA laboratory in Grenoble develops asynchronous (i.e. clockless) processors for which samples are collected each time some event occurs, such as levelcrossing of an analog signal.
For these asynchronous processors, all the usual tools of microelectrnics have to be rebuilt, in particular signal processing chains.
For a few years there has been a first informal collaboration between the LJK and TIMA laboratory on nonuniform signal processing.
We have the support of the MSTIC pole of the Joseph Fourier University: TATIE project (Technologie Asynchrone et Traitement des signaux Irrégulièrement Echantillonnés, 2009–2010) and OASIS project (Ondelettes et Analyse Statistique d'échantillons Induits par le Signal, 2012–2013).
We have a certain number of common results:
 the application of usual IIR filters to nonuniform signals: [FB10], following Fabien Aeschlimann PhD [Aes06],
 the design of asynchronous filters (sampled in frequency): [BF09], [BF11a], [BF11b], [BF12],
 the analysis of lowconsumption algorithms: [FSB10],
 a Matalab toolbox SPASS (Signal Processing for ASynchronous Systems) which implements all the algorithms we have developed.
Ongoing work
We are currently working on
 a new more robust version of the SPASS toolbox,
 the comparison of fully nonuniform algorithms with resampling techniques of active parts of a sporadic signal developped in Saeed Mian Qaisar's PhD [Qai09],
 the mathematical (and statistical analysis) of the previouly developed algorithms [BC13], [BC14],
 the analysis of the reconstruction of a nonuniform signal,
 the extension of mathematical results to levelcrossing sampling problems in control, in collaboration with the GipsaLab in Grenoble.
References
[Aes06] 
Fabien Aeschlimann.
Traitement du signal échantillonné non uniformément : algorithme et architecture.
PhD thesis, INP Grenoble, February 2006. 
[BC13] 
Brigitte BidégarayFesquet and Mariane Clausel.
Level crossing sampling of strongly monoHölder functions.
10th International Conference on Sampling Theory and Applications (SampTa'13), Bremen, Germany, 2013. 
[BC14] 
Brigitte BidégarayFesquet and Marianne Clausel.
Data driven sampling of oscillating signals.
Sampling Theory in Signal and Image Processing, 13, 175–187, 2014.
 [BF09] 
Brigitte BidégarayFesquet and Laurent Fesquet.
A fully nonuniform approach to FIR filtering.
8th International Conference on Sampling Theory and Applications (SampTa'09), Marseille, France, 2009. 
[BF11a] 
Brigitte BidégarayFesquet and Laurent Fesquet.
Nonuniform filter interpolation in the frequency domain.
Sampling Theory in Signal and Image Processing, 10, 17–35, 2011. 
[BF11b] 
Brigitte BidégarayFesquet and Laurent Fesquet.
Nonuniform filter design in the logscale.
9th International Conference on Sampling Theory and Applications (SampTa'11), Singapour, 2011 
[BF12] 
Brigitte BidégarayFesquet and Laurent Fesquet.
A new synthesis approach for nonuniform filters in the logscale: proof of concept.
submitted to publication, 2012. 
[FB10] 
Laurent Fesquet and Brigitte BidégarayFesquet.
IIR Digital Filtering of Nonuniformly Sampled Signals via State Representation.
Signal Processing, 90, 2811–2821, 2010. 
[FSB10] 
Laurent Fesquet, Gilles Sicard, and Brigitte BidégarayFesquet.
Targeting ultralow power consumption with nonuniform sampling and filtering.
IEEE International Symposium on Circuits and Systems (ISCAS2010), Paris, France. 3585–3588, IEEE, 2010. 
[Qai09] 
Saeed Mian Qaisar.
Échantillonnage et traitement conditionnés par le signal : une approche prometteuse pour des traitements efficaces à pas adaptatifs.
PhD thesis, INP Grenoble, May 2009. 
(Last updated January 2015)
