Exploració per tema "Cellular radio"

Ara es mostren els items 1-20 de 48

    • A combined polling and ISMA-DS/CDMA protocol to provide QoS in packet mobile communications systems 

      Pérez Romero, Jordi; Agustí Comes, Ramon; Sallent Roig, Oriol (Institute of Electrical and Electronics Engineers (IEEE), 2000)
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      This paper presents a new mechanism that combines the flexibility of an access protocol such as ISMA-DS/CDMA with the ability of a polling mechanism to provide a specific bound for the access delay. This protocol is proposed ...

    • A fuzzy-based call admission control system for wireless cellular networks 

      Barolli, Leonard; Xhafa Xhafa, Fatos; Durresi, Arjan; Koyama, Akio (Institute of Electrical and Electronics Engineers (IEEE), 2007)
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      The mobile cellular systems are expected to support multiple services with guaranteed quality of service (QoS). However, the ability of wireless systems to accommodate expected growth of traffic load and broadband services ...

    • A fuzzy-based handover system for avoiding ping-pong effect in wireless cellular networks 

      Barolli, Leonard; Xhafa Xhafa, Fatos; Durresi, Arjan; Koyama, Akio (Institute of Electrical and Electronics Engineers (IEEE), 2008)
      Text en actes de congrés
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      Many handover algorithms are proposed in the literature. However, to make a better handover and keep the QoS in wireless networks is very difficult. In this paper, we propose a new handover system based on fuzzy logic. The ...

    • A generic radio channel emulator to evaluate higher layer protocols in a CDMA system 

      Umbert Juliana, Anna; Díaz Romero, M. del Pilar (Institute of Electrical and Electronics Engineers (IEEE), 2000)
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      Currently, we are involved in the standardisation process to specify the next mobile system generation. A wideband code division multiple access (WCDMA) system is considered in most of the region versions. It would be very ...

    • Achievable data rate of coordinated multi-point transmission for visible light communications 

      Dowhuszko, Alexis; Pérez Neira, Ana Isabel (Institute of Electrical and Electronics Engineers (IEEE), 2017)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      This paper studies the sum data rate that a Visible Light Communication (VLC) system with multiple users canachieve when phosphor-converted white LED panels are usedto provide illumination and communication simultaneously. ...

    • Adaptive Beamforming for High Bit Rate Services in the FDD Mode of UTRA 

      Mestre Pons, Francesc X.; Nájar Martón, Montserrat; Antón Haro, Carles; Rodríguez Fonollosa, Javier (Institute of Electrical and Electronics Engineers (IEEE), 1999)
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      Most time-reference beamforming algorithms suffer from severe beampattern distortion effects when applied to high bit rate services in WCDMA, causing serious performance degradation in terms of output BER, especially at ...

    • Adaptive S-ALOHA CDMA as an alternative way of integrating services in mobile environments 

      Sallent Roig, Oriol; Agustí Comes, Ramon (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2000-05)
      Article
      Accés obert
      Code-division multiple-access (CDMA) schemes appear to be very promising access techniques for coping with the requirements of third-generation mobile systems, mainly because of their flexibility. This paper proposes an ...

    • Adaptive s-aloha cdma as an alternative way of integrating services in mobile environments 

      Sallent Roig, Oriol; Agustí Comes, Ramon (2000-05)
      Article
      Accés obert
      Code-division multiple-access (CDMA) schemes appear to be very promising access techniques for coping with the requirements of third-generation mobile systems, mainly because of their flexibility. This paper proposes an ...

    • Adaptive schemes for packet data in a ds-cdma environment 

      Sallent Roig, Oriol; Agustí Comes, Ramon (IEEE INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS, INC., 1997)
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      This paper presents a novel adaptive DS-CDMA slotted-ALOHA packet random access scheme for improving the throughput of the conventional DS-CDMA slotted-ALOHA system. For this purpose a mobile-assisted algorithm is envisaged ...

    • Advances in wireless community networks with the community-lab testbed 

      Navarro Moldes, Leandro; Baig Viñas, Roger; Barz, Christoph; Bonicioli, Joseph; Braem, Bart; Freitag, Fèlix; Vilalta i Balaguer, Ivan (2016-07)
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      Accés obert
      Beyond traditional telecom providers, citizens and organizations pool their own resources and coordinate in order to build local network infrastructures to address the digital divide in many parts of the world. These ...

    • An intelligent handoff system for wireless cellular networks using fuzzy logic and random walk model 

      Barolli, Leonard; Xhafa Xhafa, Fatos; Durresi, Arjan; Koyama, Akio; Takizawa, Makoto (Institute of Electrical and Electronics Engineers (IEEE), 2008)
      Text en actes de congrés
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      In mobile cellular systems the handover is a very important process to maintain the desired Quality of Service (QoS). Many handover algorithms are proposed in the literature. However, to make a better handover and keep the ...

    • An interference analysis on cellular mobile radiocommunications using CAD/CAE techniques 

      Marti, Javier; Cardona, Narcís; Ferrando Bataller, Miquel (Institute of Electrical and Electronics Engineers (IEEE), 1992)
      Comunicació de congrés
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      The cochannel interference in a base-station's receiver of one cell produced by a mobile in another cell that uses the same frequency is studied. An OMNISYS simulation model of channel-plus-receiver is proposed and used ...

    • Array joint detection for C/TDMA systems in UMTS environments 

      Antón Haro, Carles; Rodríguez Fonollosa, José Adrián; Rodríguez Fonollosa, Javier (Institute of Electrical and Electronics Engineers (IEEE), 1998)
      Text en actes de congrés
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      Two array-based schemes for intracell and intercell interference suppression are proposed. In both cases, the spatial and temporal characteristics of the propagation are jointly exploited by placing a narrowband beamformer ...

    • Blind channel estimation and data detection using hidden Markov models theory 

      Antón Haro, Carles; Rodríguez Fonollosa, José Adrián; Rodríguez Fonollosa, Javier (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1997-01-01)
      Article
      Accés obert
      In this correspondence, we propose applying the hidden Markov models (HMM) theory to the problem of blind channel estimation and data detection. The Baum–Welch (BW) algorithm, which is able to estimate all the parameters ...

    • Blind multi-user combining at the base station for asynchronous CDMA systems 

      Muñoz Medina, Olga; Fernández Rubio, Juan Antonio (Institute of Electrical and Electronics Engineers (IEEE), 1996)
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      This paper studies the potential benefits of antenna arrays in cellular CDMA communications and proposes a powerful scheme to undertake the array processing at the base station in CDMA mobile systems. The proposed technique ...

    • Blind multiuser deconvolution in fading and dispersive channels 

      Rodríguez Fonollosa, Javier; Rodríguez Fonollosa, José Adrián; Zvonar, Z; Vidal Manzano, José (. S.N., 1995)
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      An adaptive near-far resistant technique for the blind joint multiuser identification and detection in asynchronous CDMA systems is analyzed in fading and dispersive GSM channels.

    • Capacity self-planning in small cell multi-tenant 5G networks 

      Muñoz, Pablo; Sallent Roig, Oriol; Pérez Romero, Jordi (Institute of Electrical and Electronics Engineers (IEEE), 2017)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Multi-tenancy allows diverse agents sharing the infrastructure in the 5th generation of mobile networks. Such a feature calls for more automated and faster planning procedures in order to adapt the network capacity to the ...

    • Chip level simulation of the downlink in UTRA-FDD 

      Olmos Bonafé, Juan José; Ruiz Boqué, Sílvia (Institute of Electrical and Electronics Engineers (IEEE), 2000)
      Text en actes de congrés
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      The specifications of UMTS Terrestrial Radio Access (UTRA) for the physical layer of the downlink make use of orthogonal variable spreading factor (OVSF) codes to preserve the orthogonality between downlink channels of ...

    • Cooperative spectrum sharing in 5G access and backhaul networks 

      Rony, Rakibul Islam; López Aguilera, M. Elena; García Villegas, Eduard (Institute of Electrical and Electronics Engineers (IEEE), 2018)
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      Stringent demands for a continuous evolution of cellular networks push today academic and industrial researchers to re-think backhaul solutions for 5G. In one hand, wireless backhaul solutions are cost effective and easy ...

    • Cooperative transmission scheme to address random orientation and blockage events in VLC systems 

      Genovés Guzmán, Borja; Dowhuszko, Alexis; Gil Jiménez, Víctor P.; Pérez Neira, Ana Isabel (Institute of Electrical and Electronics Engineers (IEEE), 2019)
      Text en actes de congrés
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      Visible light communication (VLC) is a promising communication technology that paves the way to the Internet of Things. The forthcoming Industry 4.0 requires reliable high-speed communication links, which can be easily ...