Center Tecnolgic Of Telecomunicacions Of Catalonia

Castelldefels, Spain

Center Tecnolgic Of Telecomunicacions Of Catalonia

Castelldefels, Spain
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Rottenberg F.,Catholic University of Louvain | Rottenberg F.,Free University of Colombia | Mestre X.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Horlin F.,Free University of Colombia | Louveaux J.,Catholic University of Louvain
IEEE Transactions on Signal Processing | Year: 2017

The design of linear precoders or decoders for multiuser multiple-input multiple-output filterbank multicarrier (FBMC) modulations in the case of a strong channel frequency selectivity is presented. The users and the base station (BS) communicate using space division multiple access. The low complexity proposed solution is based on a single tap per-subcarrier precoding/decoding matrix at the BS in the downlink/uplink. As opposed to classical approaches that assume flat channel frequency selectivity at the subcarrier level, the BS does not make this assumption and takes into account the distortion caused by channel frequency selectivity. The expression of the FBMC asymptotic mean squared error (MSE) in the case of strong channel selectivity derived in earlier works is developed and extended. The linear precoders and decoders are found by optimizing the MSE formula under two design criteria, namely zero forcing or minimum MSE. Finally, simulation results demonstrate the performance of the optimized design. As long as the number of BS antennas is larger than the number of users, it is shown that those extra degrees of freedom can be used to compensate for the channel frequency selectivity. © 2016 IEEE.

Closas P.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Bugallo M.F.,State University of New York at Stony Brook
2011 4th IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing, CAMSAP 2011 | Year: 2011

In the literature, there are claims stating that particle filters cannot be used for complex systems because their random measures degenerate to single particles. While this is true for standard implementation of these filters, it does not hold true for alternative approaches. A new methodology based on the principle of divide and conquer has already been proposed, where the collapse of traditional particle filtering is avoided by setting an interconnected network of filters, each of them working on lower dimensional spaces. In this paper we propose an enhanced version of multiple particle filtering, which uses tools of game theory for improved performance of the overall system. Computer simulations show that the new approach outperforms both standard and multiple particle filters. © 2011 IEEE.

Cocco G.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Pfletschinger S.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Navarro M.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Ibars C.,Center Tecnolgic Of Telecomunicacions Of Catalonia
Eurasip Journal on Wireless Communications and Networking | Year: 2010

Network coding allows to exploit spatial diversity naturally present in mobile wireless networks and can be seen as an example of cooperative communication at the link layer and above. Such promising technique needs to rely on a suitable physical layer in order to achieve its best performance. In this paper, we present an opportunistic packet scheduling method based on physical layer considerations. We extend channel adaptation proposed for the broadcast phase of asymmetric two-way bidirectional relaying to a generic number M of sinks and apply it to a network context. The method consists of adapting the information rate for each receiving node according to its channel status and independently of the other nodes. In this way, a higher network throughput can be achieved at the expense of a slightly higher complexity at the transmitter. This configuration allows to perform rate adaptation while fully preserving the benefits of channel and network coding. We carry out an information theoretical analysis of such approach and of that typically used in network coding. Numerical results based on nonbinary LDPC codes confirm the effectiveness of our approach with respect to previously proposed opportunistic scheduling techniques. Copyright © 2010 Giuseppe Cocco et al.

Miozzo M.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Baldo N.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Guerra F.,University of Padua | Rossi M.,University of Padua | Zorzi M.,University of Padua
Eurasip Journal on Wireless Communications and Networking | Year: 2010

We present Miracle, a novel framework which extends ns2 to facilitate the simulation and the design of beyond 4G networks. Miracle enhances ns2 by providing an efficient and embedded engine for handling cross-layer messages and, at the same time, enabling the coexistence of multiple modules within each layer of the protocol stack. We also present a novel framework developed as an extension of Miracle called Miracle PHY and MAC. This framework facilitates the development of more realistic Channel, PHY and MAC modules, considering features currently lacking in most state-of-the-art simulators, while at the same time giving a strong emphasis on code modularity, interoperability and reusability. Finally, we provide an overview of the wireless technologies implemented in Miracle, discussing in particular the models for the IEEE 802.11, UMTS and WiMAX standards and for Underwater Acoustic Networks. We observe that, thanks to Miracle and its extensions, it is possible to carefully simulate complex network architectures at all the OSI layers, from the physical reception model to standard applications and system management schemes. This allows to have a comprehensive view of all the interactions among network components, which play an important role in many research areas, such as cognitive networking and cross-layer design. Copyright © 2010 Nicola Baldo et al.

Pfletschinger S.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Navarro M.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Ibars C.,Center Tecnolgic Of Telecomunicacions Of Catalonia
2011 IEEE GLOBECOM Workshops, GC Wkshps 2011 | Year: 2011

We consider the application of a network coding scheme in WSN (wireless sensor networks) for robustness. The use of network coding in WSN is evaluated in terms of reliability improvement, energy efficiency and resilience to network protocol failures. We have concentrated on the evaluation of coding schemes that take advantage of the spatial diversity inherent in different layers of the communication protocol. In particular, we evaluate the effect of overhearing (opportunistic listening) on the network coding performance and investigate different schemes for energy efficiency improvement. One of the main challenges is to determine the amount of overhearing, which enables to exploit the spatial diversity without consuming too much energy. © 2011 IEEE.

Giuppi F.,University of Pavia | Georgiadis A.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Collado A.,Center Tecnolgic Of Telecomunicacions Of Catalonia | Bozzi M.,University of Pavia | Perregrini L.,University of Pavia
IEEE Antennas and Propagation Society, AP-S International Symposium (Digest) | Year: 2011

This paper presents the design of a reflectarray based on coupled oscillators, whose elements are active cavity-backed antenna oscillators. The cavity backed topology, implemented in Substrate Integrated Waveguide (SIW) technology, allows for a compact, single substrate implementation, and provides a means for the suppression of the undesired surface-wave modes and for heat dissipation. The coupling between adjacent oscillator elements in the array can be controlled by properly coupling their cavities, thus allowing for the implementation of power combining and beam scanning capabilities. A small prototype of a linear reflectarray of seven elements is designed by properly combining full-wave EM simulation for the radiating structure and nonlinear Harmonic Balance (HB) and transient analysis for the optimization of the oscillators and the study of the stability of its steady-state solutions. © 2011 IEEE.

Hakobyan A.,Memorial University of Newfoundland | McGuire P.,C CORE | Power D.,C CORE | Puestow T.,C CORE | And 3 more authors.
Canadian Conference on Electrical and Computer Engineering | Year: 2015

This research examines ground-based radar technology in measuring the displacements and deformations of various origin and demonstrates the operational and performance characteristics of ground-based radar through a series of field tests carried out in Atlantic Canada in 2012. The field tests include data collection cases for the ground-based synthetic aperture radar (IBIS-L) and for ground-based real aperture radar (IBIS-S). Some examples of applications include Big Falls Hydro-Electric Generating Plant, a gravel pit, a building on the Memorial University of Newfoundland (MUN) campus, and vertical and horizontal structures (skywalk bridge and chimney), also located on the MUN campus. The IBIS (Image By Interferometric Survey) ground-based radar sensor was developed by the IDS (Ingegneria dei Sistemi SpA), Italy, and is owned by C-CORE, Canada. © 2015 IEEE.

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