Ara es mostren els items 41-60 de 141

    • Digital phase estimation method based on Karhunen-Loève series expansion for Coherent Phase Diversity Detection 

      Fàbrega Sánchez, Josep Maria; Prat Gomà, Josep Joan (2010)
      Text en actes de congrés
      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.
    • Digital pre-emphasis for 10Gb/s with low-cost directly phase-modulated lasers for PONs 

      Tabares Giraldo, Jeison; Napoli, Antonio; Polo Querol, Víctor; Calabro, S.; Sommerkorn-Krombholz, B.; Spinnler, B.; Prat Gomà, Josep Joan (Optical Society of American (OSA), 2018)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      We apply digital pre-emphasis to compensate for the frequency response non-idealities of low-cost optical transmitters. It enables transmission beyond 10Gb/s with 2/4/8-DPSK using directly modulated lasers and coherent ...
    • Dimensioning OLT architectures for UDWDM-PONs employing coherent transceivers 

      Segarra Mullerat, Josep; Sales Zaragozá, Vicente; Polo Querol, Víctor; Prat Gomà, Josep Joan (Institute of Electrical and Electronics Engineers (IEEE), 2015)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Ultra-Dense Wavelength Division Multiplexing (UDWDM) is a new method for access PON, introducing the wavelength-to-the-user concept. The main technology will be a cost-effective coherent detection scheme providing low-cost ...
    • Direct phase modulation DFBs for cost-effective ONU transmitter in udWDM PONs 

      Cano Valadéz, Iván Nicolás; Lerín de la Santísima Trinidad, Adolfo; Polo Querol, Víctor; Prat Gomà, Josep Joan (2014-05-15)
      Article
      Accés restringit per política de l'editorial
      A technique for direct phase modulating a low-cost distributed feedback laser is presented for user transmitter in ultra dense wavelength division multiplexing passive optical networks. It consists of a simple RC network, ...
    • Direct phase modulation for UDWDM ONU with beat signals 

      Velásquez Micolta, Juan Camilo; Cano Valadez, Iván Nicolás; Tabares Giraldo, Jeison; Polo Querol, Víctor; Prat Gomà, Josep Joan (Institute of Electrical and Electronics Engineers (IEEE), 2018)
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      An ONU transmitter for UDWDM PONs based on direct phase modulated distributed feedback lasers (DFB) through digital beat signals is proposed and experimentally tested. The amplitude and duty cycle of the modulating signal ...
    • Direct phase modulation of a DFB laser for udWDM-PON 

      Cano Valadéz, Iván Nicolás; Lerín de la Santísima Trinidad, Adolfo; Polo Querol, Víctor; Prat Gomà, Josep Joan (Institute of Electrical and Electronics Engineers (IEEE), 2014)
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      Accés restringit per política de l'editorial
      The response of a DFB was equalized with a simple RC network for modulating directly its phase and producing a BPSK signal. The system was tested with a heterodyne coherent detector at 1.25 Gb/s and 2.5 Gb/s showing a ...
    • Dispersion-shifted fiber polarization scrambler based on faraday effect 

      Prat Gomà, Josep Joan; Comellas Colomé, Jaume (1999-07)
      Article
      Accés obert
      Demonstration of an all-fiber polarization scrambler based on the Faraday effect is carried out. The device has been constructed using dispersion-shifted fiber that has a major tolerance to bends than standard single-mode ...
    • DQPSK directly phase modulated DFB for flexible coherent UDWDM-PONs 

      Cano Valadéz, Iván Nicolás; Lerín de la Santísima Trinidad, Adolfo; Prat Gomà, Josep Joan (2015-09-15)
      Article
      Accés obert
      A bandwidth-limited distributed feedback laser directly phase modulated with a 5-Gb/s differential quadrature phase shift keying (DQPSK) signal is demonstrated in a statistical ultra-dense wavelength division multiplexing ...
    • Dual-operability and bandwidth partitioning enabled by an ONU with tandem-modulator 

      Schrenk, Bernhard; Bauwelinck, Johan; Lázaro Villa, José Antonio; Kazmierski, Christophe; Xing-Zhi, Qiu; Prat Gomà, Josep Joan (IEEE Press. Institute of Electrical and Electronics Engineers, 2011-09)
      Article
      Accés restringit per política de l'editorial
      An upgrade at the physical layer regarding unbundling and dynamic bandwidth provisioning of a wavelength division multiplexed access network is presented. The capability of a reflective modulator to act as a photodetector ...
    • Employing feed-forward downstream cancellation in optical network units for 2.5G/1.25G RSOA-based and 10G/10G REAM-based passive optical networks for efficient wavelength reuse 

      Schrenk, Bernhard; Lázaro Villa, José Antonio; Prat Gomà, Josep Joan (IEEE Press. Institute of Electrical and Electronics Engineers, 2009-06-28)
      Text en actes de congrés
      Accés obert
      Optical Network Units for Next-Generation Passive Optical Networks with wavelength reuse are investigated for asymmetrical 2.5 G/1.25 G and symmetrical 10 G/10 G down- and upstream data rates. The transmission performance ...
    • Enhancing dynamic student learning by teamwork in innovative projects at an Erasmus Mundus master subject adapted to the EHEA (EEES) 

      Lázaro Villa, José Antonio; Prat Gomà, Josep Joan; Fàbrega Canudas, José; Kouloumentas,, Christos (Universitat Politècnica de Catalunya. Institut de Ciències de l'Educació (ICE), 2010)
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      The EHEA (EEES in Spain) is creating common academic degree standards comparable and compatible between the European countries. The definition of the new Credit unit, the ECTS, focused on the ...
    • Evaluating the energy efficiency of DWA algorithms in UDWDM-PONs 

      Segarra Mullerat, Josep; Sales Zaragozá, Vicente; Polo Querol, Víctor; Prat Gomà, Josep Joan (2016)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Ultra-Dense Wavelength Division Multiplexing (UDWDM) has been proposed for the optical access Passive Optical Network (PON) in the COst-effective COhereNt Ultra-dense-WDM-PON for lambda-To-the-user access (COCONUT) ...
    • Experimental demonstration of a statistical OFDM-PON with multiband ONUs and elastic bandwidth allocation 

      Cano Valadéz, Iván Nicolás; Escayola Elias, Francisco Javier; Schindler, Philipp C.; Santos Blanco, M. Concepción; Polo Querol, Víctor; Leuthold, Juerg; Tomkos, Ioannis; Prat Gomà, Josep Joan (Institute of Electrical and Electronics Engineers (IEEE), 2015-01-01)
      Article
      Accés obert
      The statistical orthogonal frequency division multiplexing passive optical network (OFDM-PON) concept with multiband optical network units (ONUs) is experimentally tested with two users and an optical line terminal at 2.5/5 ...
    • 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 ...
    • Experimental demonstration of multi-band upstream in statistical OFDM-PONs and comparison with digital subcarrier assignment 

      Cano Valadéz, Iván Nicolás; Escayola Elias, Francisco Javier; Schindler, Philipp C.; Santos Blanco, M. Concepción; Polo Querol, Víctor; Leuthold, Juerg; Prat Gomà, Josep Joan (Institute of Electrical and Electronics Engineers (IEEE), 2014)
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      A multiband subcarrier allocation scheme is demonstrated for the uplink in a statistical OFDM-PON. Performance achieved is similar to digital subcarrier allocation, with the significant advantage of a lower transmitter complexity.
    • Experimental demostration of an all-fiber polarization controller based on faraday rotation 

      Prat Gomà, Josep Joan; Comellas Colomé, Jaume; Junyent Giralt, Gabriel (1995-12)
      Article
      Accés obert
      An all-fiber device for the control of the state of polarization (SOP) is presented. The controller is high speed (its time response is less than 50 ms in the worst case), low loss (insertion losses are 2.5 dB independently ...
    • Experimental evaluation and improvement methods for low cost transmitters in long reach PONs 

      Chatzi, Sotiria; Klonidis, Dimitrios; Tsekrekos, Christos P.; Lázaro Villa, José Antonio; Prat Gomà, Josep Joan; Tomkos, Ioannis (2013-12)
      Article
      Accés restringit per política de l'editorial
      In this paper, we first analyze the degradation stochastic resonance (DSR) effect in the context of adaptive averaging (AD-AVG) architectures. The AD-AVG is the adaptive version of the well-known AVG architecture . It is ...
    • Exploiting RSOA for uplink transmission with coherent detection for low cost UDWDM-PON 

      Chu, Guangyong; Lerín de la Santísima Trinidad, Adolfo; Cano Valadéz, Iván Nicolás; Polo Querol, Víctor; Tabares Giraldo, Jeison; Prat Gomà, Josep Joan (2014)
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      Accés restringit per política de l'editorial
      Upstream phase modulation exploiting low cost reflective semiconductor optical amplifier (RSOA) at ONU is applied for simplified coherent detection through DFBs as local lasers at ONU and at OLT.
    • Extension of self-seeding to 10/2.5Gb/s T(W)DM PONs through remotely pumped ODN extenders 

      Prat Gomà, Josep Joan; Schrenk, Bernhard; Bonada, F.; De Valicourt, Guilhem; Lázaro Villa, José Antonio; Brenot, Romain (Institute of Electrical and Electronics Engineers (IEEE), 2015)
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      Accés restringit per política de l'editorial
      Self-seeded upstream transmission is applied to power-splitting PONs through remote amplification at extender boxes. Tree splits up to 1:16 are found to be compatible for full-duplex 10/2.5Gb/s PONs with fully passive ...
    • Fast wavelength thermal tuning of DFB lasers for ultra dense WDM-PONs 

      Tabares Giraldo, Santiago; Polo Querol, Víctor; Prat Gomà, Josep Joan (2022-10-15)
      Article
      Accés obert
      Thermal tunability for distributed feedback lasers is generally done at slow tuning speed. We study laser current boosting and implement a pre-equalization stage for short wavelength jump, improving the tuning time to the ...