Now showing items 21-40 of 78

    • 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)
      Conference report
      Open Access
      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 ...
    • Assymptotic performance of hierarchical fuzzy interference cancellers for CDMA 

      Pérez Neira, Ana Isabel; Bas, J. (2003)
      Conference report
      Open Access
      This paper presents a hierarchical fuzzy logic canceller that suppresses digital and/or analog interference from a CDMA signal. The optimum filter to remove them is the Conditional Mean Estimator (CME) or the MAP detector ...
    • Automatic rate adaptation and energy-saving mechanisms based on cross-layer information for packet-switched data networks 

      Alonso Zárate, Luis Gonzaga; Agustí Comes, Ramon (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2004-03)
      Article
      Open Access
      A set of novel PHY-MAC mechanisms based on a cross layer dialogue have been proposed, and their performance has been analyzed. System efficiency improvement is achieved by means of automatic transmission rate adaptation, ...
    • Average block error probability in the reverse link of a packet DS/CDMA system under Rayleigh fading channel conditions 

      Pérez Romero, Jordi; Alonso Zárate, Luis Gonzaga; Agustí Comes, Ramon (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2000-04)
      Article
      Open Access
      Analytic expressions have been derived for the probability density functions of the total signal-to-interference ratio when considering mixed-type interference sources in the reverse link of a DS/CDMA packet radio system ...
    • Average block error probability in the reverse link of a packet ds/cdma system under rayleigh fading channel conditions 

      Pérez Romero, Jordi; Alonso Zárate, Luis Gonzaga; Agustí Comes, Ramon (2000-04)
      Article
      Open Access
      Analytic expressions have been derived for the probability density functions of the total signal-to-interference ratio when considering mixed-type interference sources in the reverse link of a DS/CDMA packet radio system ...
    • Beamforming and Multiuser Detection in CDMA Systems with External Interferences 

      Muñoz Medina, Olga; Fernández Rubio, Juan Antonio (ICASSP'99, 1999)
      Conference report
      Open Access
      Multiuser detection has been investigated to mitigate the near-far effect in CDMA systems. Antenna arrays have been shown to provide spatial diversity and cancel undesired signals. In this paper we consider the synergy of ...
    • Blind equalization of DS-CDMA and MC-CDMA modulations in time-variant frequency selective channels 

      Rey Micolau, Francesc; Vázquez Grau, Gregorio (Institute of Electrical and Electronics Engineers (IEEE), 1999)
      Conference report
      Open Access
      The paper addresses the blind equalization problem of spread spectrum modulations in the presence of fast time-variant frequency-selective channels. The basic assumption of the paper is that the channel response exhibits ...
    • 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)
      Conference report
      Open Access
      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 detection using hidden markov models theory 

      Antón Haro, Carles; Rodríguez Fonollosa, José Adrián; Rodríguez Fonollosa, Javier (BOB WERNER IEEE, 1996)
      Conference report
      Open Access
      We present an adaptive algorithm based on the theory of hidden Markov models (HMM) which is capable of jointly detecting the users in a DS-CDMA system. The proposed technique is near-far resistant and completely blind in ...
    • Blind multiuser detection with probabilistic algorithms - application to underwater communications 

      Antón Haro, Carles; Rodríguez Fonollosa, José Adrián; Zvonar, Zaran; Rodríguez Fonollosa, Javier (IEEE IEEE, 1997)
      Conference report
      Open Access
      In this paper, two probabilistic adaptive algorithms for jointly detecting active users in a DS-CDMA system are compared. The first one, which is based on the theory of hidden Markov models (HMM) is proposed within the ...
    • Blind multiuser identification and detection in cdma systems 

      Rodríguez Fonollosa, Javier; Rodríguez Fonollosa, José Adrián; Zvonar, Z; Vidal Manzano, José (Institute of Electrical and Electronics Engineers (IEEE), 1995)
      Conference report
      Open Access
      Multiuser detection in code division multiple access systems usually requires either knowledge of the transmitted signature sequences and channel state information or use of a known training sequence for adaptation. We ...
    • Cdma blind channel equalization: a weighted subsface a proach 

      Ruiz Feliu, Rafael; Cabrera-Bean, Margarita (Institute of Electrical and Electronics Engineers (IEEE), 1999)
      Conference report
      Open Access
      This paper considers the problem of blind demodulation of multiuser information symbols in a direct-sequence code-division multiple access (DS-CDMA) environment. Channel estimation and symbol detection in the presence of ...
    • Constant-gain envelope tracking in a UHF outphasing transmitter based on continuousmode class-E GaN HEMT PAs 

      Ruiz Lavin, Maria de las Nieves; Benito, Adán L.; Pérez Cisneros, J. R.; Gilabert Pinal, Pere Lluís; Montoro López, Gabriel; García, J. A. (Institute of Electrical and Electronics Engineers (IEEE), 2016)
      Conference report
      Restricted access - publisher's policy
      A UHF outphasing transmitter, based on continuous-mode class-E power amplifiers (PAs) and implementing a constant-gain envelope tracking (ET) strategy, is presented in this paper. Drain terminating and biasing networks are ...
    • Cross-layer schedulling strategy for UMTS downlink enhancement 

      Ferrús Ferré, Ramón Antonio; Alonso Zárate, Luis Gonzaga; Umbert Juliana, Anna; Revés Ballesté, Xavier; Pérez Romero, Jordi; Casadevall Palacio, Fernando José (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2005-06)
      Article
      Open Access
      This article describes the benefits of including cross-layer information in the scheduling mechanism of a UMTS downlink channel. In particular, the information obtained from the fast power control algorithm is used to ...
    • D2. Estructuras de detector multiusuario para CDMA síncrono y asíncrono 

      Lamarca Orozco, M. Meritxell; Rey Micolau, Francesc; Riba Sagarra, Jaume; Sala Álvarez, José; Vázquez Grau, Gregorio; Villares Piera, Nemesio Javier (2008-11-10)
      Research report
      Restricted access - confidentiality agreement
    • Decentralised multi-access MAC protocol for ad-hoc networks 

      Realp, Marc; Pérez Neira, Ana Isabel (2003)
      Conference report
      Open Access
      In ad-hoc radio networks, mechanisms on how to access the radio channel are extremely important in order to improve network efficiency and, when needed, to guarantee QoS. Traditionally, Medium Access Control (MAC) protocols ...
    • Design and implementation of a wide-band real-time mobile channel emulator 

      Olmos Bonafé, Juan José; Gelonch Bosch, Antonio José; Casadevall Palacio, Fernando José; Femenias Nadal, Guillem (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1999-05)
      Article
      Open Access
      A new wide-band mobile channel emulator for the CODIT project is designed and implemented. The UMTS code-division testbed (CODIT R2020) is a research project within the European RACE-II program set up by the Commission of ...
    • Design and implementation of a wide-band real-time mobile channel emulator 

      Olmos Bonafé, Juan José; Gelonch Bosch, Antonio José; Casadevall Palacio, Fernando José; Femenias Nadal, Guillem (1999-05)
      Article
      Open Access
      A new wide-band mobile channel emulator for the CODIT project is designed and implemented. The UMTS code-division testbed (CODIT R2020) is a research project within the European RACE-II program set up by the Commission of ...
    • Diseño y desarrollo de una CNG orientado a Linux Embedded 

      Martínez García, Rebeca (Universitat Politècnica de Catalunya, 2010-04-06)
      Master thesis
      Open Access
    • Diversity in mobile communications for blind detection of block-coded modulations 

      Vázquez Grau, Gregorio; Rey Micolau, Francesc; Lamarca Orozco, M. Meritxell; Rodríguez Fonollosa, Javier (Institute of Electrical and Electronics Engineers (IEEE), 1999)
      Conference report
      Open Access
      Spatial, temporal, and frequency diversity structures are analyzed to address the blind equalization problem in the presence of time-variant frequency selective channels. The aim of the paper is to present equalization ...