Combastel C.,ENSEA Cergy
Automatica | Year: 2015
State bounding observation based on zonotopes is the subject of this paper. Dealing with zonotopes is motivated by set operations resulting in simple matrix calculations with regard to the often huge number of facets and vertices of the equivalent polytopes. Discrete-time LTV/LPV systems with state and measurement uncertainties are considered. Based on a new zonotope size criterion called FW-radius, and by merging optimal and robust observer gain designs, a Zonotopic Kalman Filter (ZKF) is proposed with a proof of robust convergence. The notion of covariation is introduced and results in an explicit bridge between the zonotopic set-membership and the stochastic paradigms for Kalman Filtering. No intersection is used and the influence of the reduction operator limiting to a tunable maximum the size of the matrices involved in the zonotopic set computations is fully taken into account in the LMI-based robust stability analysis. A numerical example illustrates the effectiveness of the proposed ZKF. © 2015 Elsevier Ltd.
Sassatelli L.,French National Center for Scientific Research |
Declercq D.,ENSEA Cergy
IEEE Transactions on Information Theory | Year: 2010
In this paper, a new class of low-density parity-check (LDPC) codes, named hybrid LDPC codes, is introduced. Hybrid LDPC codes are characterized by an irregular connectivity profile and heterogeneous orders of the symbols in the codeword. It is shown in particular that the class of hybrid LDPC codes can be asymptotically characterized and optimized using density evolution (DE) framework, and a technique to maximize the minimum distance of the code is presented. Numerical assessment of hybrid LDPC code performances is provided, by comparing them to protograph-based and multiedge-type (MET) LDPC codes. Hybrid LDPC codes are shown to allow to achieve an interesting tradeoff between good error-floor performance and good waterfall region with nonbinary coding techniques. © 2010 IEEE.
Paolini E.,University of Bologna |
Fossorier M.P.C.,ENSEA Cergy |
Chiani M.,University of Bologna
IEEE Transactions on Information Theory | Year: 2010
In this paper, a method for the asymptotic analysis of generalized low-density parity-check (GLDPC) codes and doubly generalized low-density parity-check (D-GLDPC) codes over the binary erasure channel (BEC), based on extrinsic information transfer (EXIT) chart, is described. This method overcomes the problem consisting of the impossibility to evaluate the EXIT function for the check or variable component codes, in situations where the information functions or split information functions for component codes are unknown. According to the proposed technique, GLDPC codes and D-GLDPC codes where the generalized check and variable component codes are random codes with minimum distance at least 2, are considered. A technique is then developed which finds the EXIT chart for the overall GLDPC or D-GLDPC code, by evaluating the expected EXIT function for each check and variable component code. This technique is finally combined with the differential evolution algorithm in order to generate some good GLDPC and D-GLDPC edge distributions. Numerical results of long, random codes, are presented which confirm the effectiveness of the proposed approach. They also reveal that D-GLDPC codes can outperform standard LDPC codes and GLDPC codes in terms of both waterfall performance and error floor. © 2006 IEEE.
Aggoune W.,ENSEA Cergy
Proceedings of the IEEE Conference on Decision and Control | Year: 2011
In this paper, the problem of feedback stabilization of stochastic differential delay systems is considered. The systems under study are nonlinear, nonaffine and involve both discrete and distributed delays. By using a LaSalle-type theorem for stochastic systems, general conditions for stabilizing the closed-loop system with delays are obtained. In addition, stabilizing state feedback control laws are proposed. © 2011 IEEE.
Agency: Cordis | Branch: FP7 | Program: NOE | Phase: ICT-2007.1.1 | Award Amount: 9.17M | Year: 2008
NEWCOM\\ is the acronym of a proposed Network of Excellence in Wireless COMmunications, submitted to Call 1 of the VII Framework Programme under the Objective ICT-2007.1.1: The Network of the Future, mainly in its target direction Ubiquitous network infrastructure and architectures. The current proposal draws inspiration, shape/form, and substantive direction from its successful predecessor, the NoE NEWCOM, which was approved and funded by the EC for 36 months starting March 1st, 2004 and ending February 28, 2007. At the same time, NEWCOM\\ aspires to inject new vision, expanded roles, ever-higher degrees of research integration, and a definitive roadmap to financial security for the long-term life of this undertaking in the European research and higher-learning space. The core concept of NEWCOM\\ is that of an NoE of medium size, greatly reduced from the initial NEWCOM Consortium, formed by keeping the most committed and performing partners, exploiting the successful integration tools that NEWCOM designed and activated, and which is created for the purpose of scientifically addressing medium/long term, complex, interdisciplinary, fundamental research problems in the field of wireless networks, focused towards identifying, posing in the right modelling perspective, and at least partially characterizing the information-communication theoretical limits. Its main objectives are: Identify a selective set of scenarios, Define suitable performance measures that take into account the wireless channel nature, Perform a detailed analysis of the main theoretical results available, Evaluate information-theoretical bounds on the achievable performance, Design and analyze transmitting/receiving algorithms and protocols in order to approach those limits, Analyze implementation aspects of the above algorithms in flexible, energy-aware user terminals, Output the major findings into an integrated simulation library, Enhance the already good cooperation level among research