Ara es mostren els items 1-20 de 20

    • All-Optical Intra-PON Data Routing Between ONUs with a MG-Y Tunable Laser as 2.5 Gbps Burst-Mode Transmitter 

      Bonada Bó, Francesc Xavier; Schrenk, Bernhard; Fàbrega Sánchez, Josep Maria; Lázaro Villa, José Antonio; Forzati, Marco; Jean Rigole,, Pierre; Prat Gomà, Josep Joan (Institute of Electrical and Electronics Engineers (IEEE), 2011)
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      Direct communication between ONUs is experimentally demonstrated with a tunable MG-Y laser in a ring+tree PON for 640 users, without passing electrically powered equipment.
    • Channel crosstalk in ultra-dense WDM PON using time-switched phase diversity optical homodyne reception 

      Fàbrega Sánchez, Josep Maria; Prat Gomà, Josep Joan (Marian Marciniak, IEEE, 2007)
      Text en actes de congrés
      Accés obert
      Experimental study of channel crosstalk effects in time-switched phase diversity optical homodyne reception is presented, precisely focused towards ultra-dense wavelength division multiplexed (WDM) passive optical networks ...
    • Data plane elements for optical performance monitoring agnostic to the modulation format for disaggregated optical networks 

      Fàbrega Sánchez, Josep Maria; Locatelli, Fabiano; Nadal Reixats, Laia; Christodoulopoulos, Konstantinos; Svaluto Moreolo, Michela; Spadaro, Salvatore (2020)
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      In this paper, data plane alternatives for optical performance monitoring are presented as enablers to address the key challenges in disaggregated optical networks. In fact, a key element of the disaggregated networks is ...
    • Decomposed radio access network over deployed passive optical networks using coherent optical OFDM transceivers 

      Fàbrega Sánchez, Josep Maria; Svaluto Moreolo, Michela; Chochol, Marcin; Junyent Giralt, Gabriel (Institute of Electrical and Electronics Engineers (IEEE), 2013-04-04)
      Article
      Accés restringit per política de l'editorial
      In this paper, it is proposed to take advantage of the deployed passive optical network (PON) infrastructure by overlaying a decomposed radio access network (RAN) using a very dense WDM. Coherent optical orthogonal ...
    • Demonstration of a full duplex PON featuring 2.5 Gbps Sub Carrier Multiplexing downstream and 1.25 Gbps upstream with colourless ONU and simple optics 

      Fàbrega Sánchez, Josep Maria; López Pastor, Eduardo Tommy; Lázaro Villa, José Antonio; Zuhdi, Muneer; Prat Gomà, Josep Joan (2008)
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      We demonstrate a full-duplex DPSK SCM PON operating at 2.5Gbps/1.25Gbps bitrates, with RSOA ONU and simplified scheme. It achieves low sensitivity and is implemented with low-cost components.
    • Deployment analysis of TDM/WDM single fiber PON with colourless ONU operating at 2.5 Gbps subcarrier multiplexed downstream and 1.25 gbps upstream 

      Fàbrega Sánchez, Josep Maria; El Mardini, Ahmad; Polo Querol, Víctor; Lázaro Villa, José Antonio; López Pastor, Eduardo Tommy; Soila, Risto; Prat Gomà, Josep Joan (2010)
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      Accés obert
      A single-fiber full-duplex hybrid TDM/WDM-PON is demonstrated to operate at 2.5/1.25 Gbps rates, with RSOA ONU. It achieves high power budget (GPON compliant) at a distances higher than 20km, and serves up to 1280 users.
    • Design of a wavelength control for coherent detection of high order modulation formats 

      Fàbrega Sánchez, Josep Maria; Prat Gomà, Josep Joan; Molle, Lutz; Freund, Ronald (IEEE Press. Institute of Electrical and Electronics Engineers, 2009)
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      An automatic frequency control design is proposed and demonstrated. It is based on a high-speed optical VCO. An overall design has been performed, based on simulation results. Also, loop delay and phase noise impacts have ...
    • Digital phase estimation method based on Karhunen-Loève series expansion for Coherent Phase Diversity Detection 

      Fàbrega Sánchez, Josep Maria; Prat Gomà, Josep Joan (2010)
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      Accés obert
      A novel phase estimation method for coherent systems is presented and demonstrated. It outperforms 5.5 times the phase noise and spectral width tolerance respect to the other methods.
    • Experimental demonstration of heterodyne phase-locked loop for optical homodyne PSK receivers in PONs 

      Fàbrega Sánchez, Josep Maria; Vilabrú, Lluís; Prat Gomà, Josep Joan (2008)
      Text en actes de congrés
      Accés obert
      Experimental demonstration of heterodyne optical Phase-Locked Loop (oPLL), using simplest optics, is carried out. For the first time, the effect of loop delay has been experimentally characterized and compared directly to ...
    • Filter features extraction from optical spectra 

      Locatelli, Fabiano; Christodoulopoulos, Konstantinos; Fàbrega Sánchez, Josep Maria; Svaluto Moreolo, Michela; Nadal Reixats, Laia; Spadaro, Salvatore (Institute of Electrical and Electronics Engineers (IEEE), 2020)
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      We propose a method to estimate the central frequency and the bandwidth of optical filters, that relies on optical spectra captured with optical channel monitors at ROADM’s ingress port. We demonstrate for both features ...
    • Low complexity bit rate variable transponders based on optical OFDM with PAPR reduction capabilities 

      Nadal, Laia; Svaluto Moreolo, Michela; Fàbrega Sánchez, Josep Maria; Junyent Giralt, Gabriel (2012)
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      In this paper, we propose low complexity bit rate variable transponders for adaptive DC biased Optical OFDM systems. The transponders are based on an alternative transform, the fast Hartley transform (FHT), and use ...
    • Low complexity PAPR reduction techniques for clipping and quantization noise mitigation in direct-detection O-OFDM systems 

      Nadal Reixats, Laia; Svaluto Moreolo, Michela; Fàbrega Sánchez, Josep Maria; Junyent Giralt, Gabriel (2014-06-01)
      Article
      Accés restringit per política de l'editorial
      We present different distortionless peak-to-average power ratio (PAPR) reduction techniques that can be easily applied, without any symmetry restriction, in direct-detection (DD) optical orthogonal frequency division ...
    • Low cost homodyne transceiver for UDWDM access networks 

      Fàbrega Sánchez, Josep Maria; Prat Gomà, Josep Joan (2009)
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      We propose and demonstrate a DPSK homodyne architecture based on a simple phase-diversity set-up with analog processing. Due to its spectral properties, it remarkably increases the phase noise tolerance of more conventional ...
    • Optical filter cascading effects in a phase modulated coherent optical OFDM transmission system based on Hartley transform 

      Chochol, M.; Fàbrega Sánchez, Josep Maria; Svaluto Moreolo, Michela; Junyent Giralt, Gabriel (IEEE, 2012)
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      Effects of cascading optical filters are investigated for a phase modulated coherent optical OFDM system based on Hartley transform. The evaluation is performed by means of numeric simulations in a 10 Gb/s system with a ...
    • Phase modulated optical OFDM upstream with IM/DD downstream for full-duplex 10 Gb/s bidirectional transmission over a single wavelength with a reflective SOA 

      Fàbrega Sánchez, Josep Maria; Chochol, Marcin; Svaluto Moreolo, Michela; Lázaro Villa, José Antonio; Junyent Giralt, Gabriel (Institute of Electrical and Electronics Engineers (IEEE), 2013)
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      The feasibility of a phase modulated optical OFDM upstream transmission employing IM/DD downstream for achieving a bidirectional transmission with symmetric data rate of 10 Gb/s over a single wavelength is investigated for ...
    • Simple intradyne PSK system for UDWDM-PON 

      Prat Gomà, Josep Joan; Polo Querol, Víctor; Zakynthinos, P.; Cano Valadéz, Iván Nicolás; Tabares, J.; Fàbrega Sánchez, Josep Maria; Klonidis, Dimitrios; Tomkos, Ioannis (2012-12-17)
      Article
      Accés obert
      A homodyne coherent receiver for ultra-dense WDM-PON with off the shelf components is presented. It consists of a conventional DFB, phase switched clock signal, an optical coupler instead of a 90º hybrid, balanced ...
    • SOA/REAM as Vector Modulator for QAM Upstream 

      Schrenk, Bernhard; Fàbrega Sánchez, Josep Maria; Kazmierski, Christophe; Lázaro Villa, José Antonio; Prat Gomà, Josep Joan (2011)
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      Simultaneous encoding of information in the optical phase and amplitude for upstream transmission is demonstrated with an integrated SOA/REAM of small form factor. The crosstalk penalties between the QAM tributaries are ...
    • Spectral processing techniques for efficient monitoring in optical networks 

      Locatelli, Fabiano; Christodoulopoulos, Konstantinos; Svaluto Moreolo, Michela; Fàbrega Sánchez, Josep Maria; Nadal Reixats, Laia; Spadaro, Salvatore (Institute of Electrical and Electronics Engineers (IEEE), 2021-07-01)
      Article
      Accés obert
      Having ubiquitous optical monitors in dense wavelength-division multiplexing (DWDM) or flex-grid networks allows the estimation in real time of crucial parameters. Such monitoring would be even more important in disaggregated ...
    • Ultra-dense, transparent and resilient ring-tree access network using coupler-based remote nodes and homodyne transceivers 

      Fàbrega Sánchez, Josep Maria; Prat Gomà, Josep Joan (IEEE Press. Institute of Electrical and Electronics Engineers, 2009)
      Text en actes de congrés
      Accés obert
      We propose an Ultra-Dense Wavelength Division Multiplex Passive Optical Network (UD-WDM-PON) based on homodyne detection in a totally transparent ring-tree implementation. It is based on time switching phase diversity ...
    • WDM overlay of distributed base stations in deployed passive optical networks using coherent optical OFDM transceivers 

      Fàbrega Sánchez, Josep Maria; Svaluto Moreolo, Michela; Chochol, M.; Junyent Giralt, Gabriel (IEEE, 2012)
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      Accés restringit per política de l'editorial
      It is proposed to reuse the deployed PON infrastructure by overlaying distributed radio base stations by means of very dense WDM with narrow channel spacings. In order to cope with that while minimizing its impact onto ...