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Publications associées (24)

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Synthesis of near-diffraction-free orbital-angular-momentum space-time wave packets having a controllable group velocity using a frequency comb

Tobias Kippenberg, Maxim Karpov, Zhe Zhao

Novel forms of light beams carrying orbital angular momentum (OAM) have recently gained interest, especially due to some of their intriguing propagation features. Here, we experimentally demonstrate the generation of near-diffraction-free two-dimensional ( ...

Optica Publishing Group2022

L'usage et l'expérience du temps de déplacement dans la perspective du report modal

Ludy Juliana González Villamizar

For several decades - and still today - mobility policies in industrialised countries have sought to reduce travel time to meet the expectations of infrastructure users for speed. However, despite major investments to achieve this objective of improving ac ...

EPFL2022

Generation of OAM-carrying space-time wave packets with time-dependent beam radii using a coherent combination of multiple LG modes on multiple frequencies

Tobias Kippenberg, Maxim Karpov, Zhe Zhao

Space-time (ST) wave packets, in which spatial and temporal characteristics are coupled, have gained attention due to their unique propagation characteristics, such as propagation invariance and tunable group velocity in addition to their potential ability ...

Optica Publishing Group2022

Tunability of space-time wave packet carrying tunable and dynamically changing OAM value

Tobias Kippenberg, Maxim Karpov

Space-time (ST) wave packets have gained much interest due to their dynamic optical properties. Such wave packets can be generated by synthesizing frequency comb lines, each having multiple complex-weighted spatial modes, to carry dynamically changing orbi ...

Optica Publishing Group2022

El espesor del camino, visto a través de dos proyectos de transporte en Argelia

Aniss Mouad Mezoued

Lane and pathway thickness: definition essay based on two case studies of Algerian transport projects. Planning and transport engineering have for a long time considered pathways and lanes as continuous lines connecting a point A to a point B. In terms of ...

2018

Heat kernel methods for Lifshitz theories

Diego Blas Temino, Mario Herrero Valea

We study the one-loop covariant effective action of Lifshitz theories using the heat kernel technique. The characteristic feature of Lifshitz theories is an anisotropic scaling between space and time. This is enforced by the existence of a preferred foliat ...

Springer Nature2017

Compact UWB antennas for Wireless Body Area Networks (W-BANs)

Anja Skrivervik, Jean-François Zürcher, Jovanche Trajkovikj

A major issue in Wireless Body Area Networks (W-BAN) is the reliability of the transmission in all conditions, thus in all locations and positions of the wearer. One way to achieve this is to design communication systems as independent as possible to the p ...

2014

Space-time modelling of extreme events

Anthony Christopher Davison, Raphaël Huser

Max-stable processes are the natural analogues of the generalized extreme-value distribution when modelling extreme events in space and time. Under suitable conditions, these processes are asymptotically justified models for maxima of independent replicati ...

Wiley-Blackwell2014

Colour simplex coding for brillouin distributed sensors

Luc Thévenaz, Marcelo Alfonso Soto Hernandez

The possibility to customize Simplex coding for long range Brillouin Optical Time Domain Analysis is demonstrated by “colouring” the sequences in the frequency domain. The coding gain is identical to the traditional intensity-modulated Simplex code, though ...

2013

Time/frequency coding for Brillouin distributed sensors

Luc Thévenaz, Marcelo Alfonso Soto Hernandez

In this paper, we propose a novel coding for long range Brillouin Optical Time Analysis (BOTDA) distributed sensors based on a combination of time and frequency pulses, resulting in an additional coding gain of √2 with respect to traditional intensit ...

2012

Comment on “Encoding many channels on the same frequency through radio vorticity: first experimental test”

Julien Perruisseau-Carrier, Michele Tamagnone

We show that the public experiment held in Venice by Tamburini et al and reported in 2012 New J. Phys. 14 033001 can be regarded as a particular implementation of multiple-input-multiple-output (MIMO) communications and, therefore, has no advantages over e ...

Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft2012

Performance analysis of dual-hop fixed-gain AF relaying systems with OSTBC over Nakagami-m fading channels

In this paper, we present outage probability and symbol error rate (SER) performance analyses of a dual-hop transmission using fixed-gain amplify-and-forward relaying in flat Nakagami-m fading channels. The system under consideration is equipped with multi ...

Elsevier Gmbh, Urban & Fischer Verlag2012

Models of non-relativistic quantum gravity: the good, the bad and the healthy

Sergey Sibiryakov, Diego Blas Temino

Horava's proposal for non-relativistic quantum gravity introduces a preferred time foliation of space-time which violates the local Lorentz invariance. The foliation is encoded in a dynamical scalar field which we call 'khronon'. The dynamics of the khrono ...

Springer Nature2011

Resource and Performance Comparisons for Different Acquisition Methods that can be Applied to a VHDL-based GPS Receiver in Standalone and Assisted Cases

Pierre-André Farine, Cyril Botteron, Jérôme Leclère

There are mainly three well-known techniques to acquire a GNSS signal. The first, called Serial Search Acquisition, consist in correlating the Pseudo-Random Noise (PRN) codes for all the codes phases and all the frequency bins. The two others make use of t ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2010

Theoretical Model of Polymer Plasma Laser Ablation

Maria-Alexandra Paun

Polymer plasma laser ablation has been investigated theoretically. An elegant mathematical tool using the fractal structure of space-time was developed. The model was verified with good accuracy on the existing experimental results. ...

2009

Linear Diversity-Embedding STBC: Design Issues and Applications

Suhas Diggavi

We design a novel class of space-time codes, called linear diversity-embedding space-time block codes (LDE-STBC) where a high-rate STBC is linearly superimposed on a high-diversity STBC without requiring channel knowledge at the transmitter. In applying th ...

2009

Diversity embedding for broadband communication

Sanket Dusad

Given uncertainty in environment, a conservative approach is to design for the worst case, leading to a game-theoretic situation where the environment is controlled by an adversary. However, in many cases, the uncertainty arises from randomness, not an adv ...

EPFL2008

Noncoherent multi-source network coding

Christina Fragouli, Suhas Diggavi, Mahdi Jafari Siavoshani

We examine the problem of multiple sources transmitting information to one or more receivers that require the information from all the sources, over a network where the network nodes perform randomized network coding. We consider the noncoherent case, wher ...

2008

Towards Reliable Broadcasting using ACKs

Christina Fragouli, Patrick Thiran, Mathilde Durvy

We propose a mechanism for reliable broadcasting in wireless networks, that consists of two components: a method for bandwidth efficient acknowledgment collection, and a coding scheme that uses acknowledgments. Our approach combines ideas from network codi ...

IEEE2007

Diversity-Multiplexing-Delay Tradeoff in Half-Duplex ARQ Relay Channels

Sanket Dusad, Tarik Tabet

In this paper, we present an efficient protocol for the delay-limited fading ARQ single relay half duplex channel. The source is using an ARQ retransmission protocol to send data to the relay and the destination. When the relay is able to decode, both the ...

2007