The Experts below are selected from a list of 28149 Experts worldwide ranked by ideXlab platform
Marc Moeneclaey - One of the best experts on this subject based on the ideXlab platform.
-
Sensitivity of orthogonal frequency-division multiplexed systems to carrier and clock synchronization errors
Signal Processing, 2000Co-Authors: Heidi Steendam, Marc MoeneclaeyAbstract:Abstract In this contribution, we present an overview of research results pertaining to the sensitivity of orthogonal frequency-division multiplexed (OFDM) systems to synchronization errors. We show that OFDM systems are quite sensitive to carrier frequency offset and clock frequency offset : in the presence of these impairments, the signal-to-noise ratio (SNR) at the input of the Decision Device is a decreasing function of the number of carriers. On the other hand, carrier phase jitter and timing jitter give rise to a degradation of the SNR at the input of the Decision Device which does not depend on the number of carriers; as compared to traditional single-carrier systems, OFDM systems have the same sensitivity to carrier phase jitter and a somewhat larger sensitivity to timing jitter.
-
Analysis and optimization of the performance of OFDM on frequency-selective time-selective fading channels
IEEE Transactions on Communications, 1999Co-Authors: Heidi Steendam, Marc MoeneclaeyAbstract:In mobile radio communication, the fading channels generally exhibit both time-selectivity and frequency-selectivity. Orthogonal frequency-division multiplexing has been proposed to combat the frequency-selectivity, but its performance is also affected by the time-selectivity. We investigate how various parameters, such as the number of carriers, the guard time length, and the sampling offset between receiver and transmitter, affect the system performance. Further, we determine the optimum values of the above parameters, which minimize the degradation of the signal to-noise ratio at the input of the Decision Device.
-
The Sensitivity of MC‐CDMA to Synchronisation Errors
European Transactions on Telecommunications, 1999Co-Authors: Heidi Steendam, Marc MoeneclaeyAbstract:In this contribution, we investigate the sensitivity of MC-CDMA systems to synchronisation errors. We show that the signal-to-noise ratio (SNR) of the MC-CDMA system at the input of the Decision Device in the presence of a carrier frequency offset or a clock frequency offset is a rapidly decreasing function of the number of carriers. For a maximal load, carrier phase jitter and timing jitter give rise to a degradation that is independent of the spectral content of the jitter; moreover, the degradation caused by carrier phase jitter is independent of the number of carriers. A constant carrier phase offset and a constant timing offset cause no degradation of the MC-CDMA system performance.
-
The effect of synchronisation errors on MC-CDMA performance
1999 IEEE International Conference on Communications (Cat. No. 99CH36311), 1999Co-Authors: Heidi Steendam, Marc MoeneclaeyAbstract:We investigate the sensitivity of MC-CDMA systems to synchronisation errors. We show that the signal-to-noise ratio (SNR) of the MC-CDMA system at the input of the Decision Device in the presence of a carrier frequency offset or a clock frequency offset is a rapidly decreasing function of the number of carriers. For a maximal load, carrier phase jitter and timing jitter give rise to a degradation that is independent of the spectral content of the jitter; moreover, the degradation caused by carrier phase jitter is independent of the number of carriers. A constant carrier phase offset and a constant timing offset cause no degradation of the MC-CDMA system performance.
-
The effect of carrier phase jitter on MC-CDMA performance
IEEE Transactions on Communications, 1999Co-Authors: Heidi Steendam, Marc MoeneclaeyAbstract:We investigate the influence of the carrier phase jitter of a phase-locked local oscillator on the performance of a multicarrier code-division multiple-access (MC-CDMA) system in a nondispersive channel. This carrier phase jitter degrades the signal-to-noise ratio at the input of the Decision Device. When all users have the same power level and phase jitter spectrum, it is shown that for the highest load, the degradation only depends on the jitter variance but not on the specific shape of the jitter spectrum nor on the number of carriers.
Heidi Steendam - One of the best experts on this subject based on the ideXlab platform.
-
Sensitivity of orthogonal frequency-division multiplexed systems to carrier and clock synchronization errors
Signal Processing, 2000Co-Authors: Heidi Steendam, Marc MoeneclaeyAbstract:Abstract In this contribution, we present an overview of research results pertaining to the sensitivity of orthogonal frequency-division multiplexed (OFDM) systems to synchronization errors. We show that OFDM systems are quite sensitive to carrier frequency offset and clock frequency offset : in the presence of these impairments, the signal-to-noise ratio (SNR) at the input of the Decision Device is a decreasing function of the number of carriers. On the other hand, carrier phase jitter and timing jitter give rise to a degradation of the SNR at the input of the Decision Device which does not depend on the number of carriers; as compared to traditional single-carrier systems, OFDM systems have the same sensitivity to carrier phase jitter and a somewhat larger sensitivity to timing jitter.
-
Analysis and optimization of the performance of OFDM on frequency-selective time-selective fading channels
IEEE Transactions on Communications, 1999Co-Authors: Heidi Steendam, Marc MoeneclaeyAbstract:In mobile radio communication, the fading channels generally exhibit both time-selectivity and frequency-selectivity. Orthogonal frequency-division multiplexing has been proposed to combat the frequency-selectivity, but its performance is also affected by the time-selectivity. We investigate how various parameters, such as the number of carriers, the guard time length, and the sampling offset between receiver and transmitter, affect the system performance. Further, we determine the optimum values of the above parameters, which minimize the degradation of the signal to-noise ratio at the input of the Decision Device.
-
The Sensitivity of MC‐CDMA to Synchronisation Errors
European Transactions on Telecommunications, 1999Co-Authors: Heidi Steendam, Marc MoeneclaeyAbstract:In this contribution, we investigate the sensitivity of MC-CDMA systems to synchronisation errors. We show that the signal-to-noise ratio (SNR) of the MC-CDMA system at the input of the Decision Device in the presence of a carrier frequency offset or a clock frequency offset is a rapidly decreasing function of the number of carriers. For a maximal load, carrier phase jitter and timing jitter give rise to a degradation that is independent of the spectral content of the jitter; moreover, the degradation caused by carrier phase jitter is independent of the number of carriers. A constant carrier phase offset and a constant timing offset cause no degradation of the MC-CDMA system performance.
-
The effect of synchronisation errors on MC-CDMA performance
1999 IEEE International Conference on Communications (Cat. No. 99CH36311), 1999Co-Authors: Heidi Steendam, Marc MoeneclaeyAbstract:We investigate the sensitivity of MC-CDMA systems to synchronisation errors. We show that the signal-to-noise ratio (SNR) of the MC-CDMA system at the input of the Decision Device in the presence of a carrier frequency offset or a clock frequency offset is a rapidly decreasing function of the number of carriers. For a maximal load, carrier phase jitter and timing jitter give rise to a degradation that is independent of the spectral content of the jitter; moreover, the degradation caused by carrier phase jitter is independent of the number of carriers. A constant carrier phase offset and a constant timing offset cause no degradation of the MC-CDMA system performance.
-
The effect of carrier phase jitter on MC-CDMA performance
IEEE Transactions on Communications, 1999Co-Authors: Heidi Steendam, Marc MoeneclaeyAbstract:We investigate the influence of the carrier phase jitter of a phase-locked local oscillator on the performance of a multicarrier code-division multiple-access (MC-CDMA) system in a nondispersive channel. This carrier phase jitter degrades the signal-to-noise ratio at the input of the Decision Device. When all users have the same power level and phase jitter spectrum, it is shown that for the highest load, the degradation only depends on the jitter variance but not on the specific shape of the jitter spectrum nor on the number of carriers.
Emad Alsusa - One of the best experts on this subject based on the ideXlab platform.
-
Pre-selection tentative Decision Device-based SIR estimator for a TD-CDMA system
IEICE Transactions on Communications, 2004Co-Authors: Yeonwoo Lee, Steve Mclaughlin, Emad AlsusaAbstract:In this letter, we address the problem of how to measure the link quality in terms of signal-to-interference ratio (SIR) in rapidly time varying channels which are due to fast variation of the interference or the bursty nature of the traffic. We propose a new SIR estimation approach for the TD-CDMA system, that is based on a pre-selection tentative Decision Device which discards and selects the estimated symbol on the basis of MAP ratio. The simulation results show that the proposed SIR estimator works and is superior to other known estimators in rapidly time varying channels.
-
ICC - Pre-selection tentative Decision Device-based SIR estimator for a UTRA-TDD system in time varying channels
2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333), 2002Co-Authors: Yeonwoo Lee, Stephen Mclaughlin, Emad AlsusaAbstract:In this paper we address the problem of how to measure the link quality in terms of signal-to-interference ratio (SIR) over rapidly time varying channels which are due to either fast variation of the interference or the bursty nature of the traffic. We propose a new SIR estimation approach for the UTRA-TDD system, that is based on a pre-selection tentative Decision Device which discards and selects the estimated symbol on the basis of MAP ratio. Simulation results show that the proposed SIR estimator works well in the context of rapidly time varying channels.
Yeonwoo Lee - One of the best experts on this subject based on the ideXlab platform.
-
Pre-selection tentative Decision Device-based SIR estimator for a TD-CDMA system
IEICE Transactions on Communications, 2004Co-Authors: Yeonwoo Lee, Steve Mclaughlin, Emad AlsusaAbstract:In this letter, we address the problem of how to measure the link quality in terms of signal-to-interference ratio (SIR) in rapidly time varying channels which are due to fast variation of the interference or the bursty nature of the traffic. We propose a new SIR estimation approach for the TD-CDMA system, that is based on a pre-selection tentative Decision Device which discards and selects the estimated symbol on the basis of MAP ratio. The simulation results show that the proposed SIR estimator works and is superior to other known estimators in rapidly time varying channels.
-
ICC - Pre-selection tentative Decision Device-based SIR estimator for a UTRA-TDD system in time varying channels
2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333), 2002Co-Authors: Yeonwoo Lee, Stephen Mclaughlin, Emad AlsusaAbstract:In this paper we address the problem of how to measure the link quality in terms of signal-to-interference ratio (SIR) over rapidly time varying channels which are due to either fast variation of the interference or the bursty nature of the traffic. We propose a new SIR estimation approach for the UTRA-TDD system, that is based on a pre-selection tentative Decision Device which discards and selects the estimated symbol on the basis of MAP ratio. Simulation results show that the proposed SIR estimator works well in the context of rapidly time varying channels.
Gilles Halin - One of the best experts on this subject based on the ideXlab platform.
-
Identifying stakeholders’ roles and relevant project documents for 4D-based collaborative Decision making
Frontiers of Engineering Management, 2019Co-Authors: Veronika Bolshakova, Antonio Guerriero, Gilles HalinAbstract:To fully understand and effectively implement 4D building information modelling (BIM) models and methods, we need to develop a precise knowledge of which project digital documents should be used and how they influence the Decision-making (DM) process. This article studies the convergence between uses of 4D BIM and digital project documents. We hypothesize that a clear visualization of the construction simulation through a 4D model is a useful source of information and a support for DM at collaborative meetings. Through this research, we continue to progress toward a new 4D-based collective Decision Device, so these elements will contribute to propose 4D BIM as DM support on architecture engineering construction (AEC) projects. Further, the present research will be complemented by results from questionnaires given at a later research stage. The article presents a brief review of BIM context to consider ways of fostering the implementation of all 4D BIM uses (not only visualization). It then introduces a proposition for 4D BIM uses implementation by the project development phase. It concludes by summarizing stakeholders’ roles and documents relevant to 4D BIM uses.
-
Identifying stakeholders’ roles and relevant project documents for 4D-based collaborative Decision making
Frontiers of Engineering Management, 2019Co-Authors: Veronika Bolshakova, Antonio Guerriero, Gilles HalinAbstract:In order to fully understand and efficiently implement 4D BIM models and methods, we need to develop a precise knowledge of which project digital documents should be used, and also how they influence the Decision-making process. This article studies the convergence between uses of 4D BIM and digital project documents. We hypothesize that a clear visualization of the construction simulation through a 4D model is a useful source of information and a support for Decision-making at collaborative meetings. Through this research we continue to progress towards a new 4D-based collective Decision Device, thus these elements will contribute to propose 4D BIM as a support for the Decision-making on AEC projects. Further, the present research will be complemented by results from questionnaires given at a later research stage. The article presents a brief review of BIM context to consider ways of fostering the implementation of all 4D BIM uses (not only visualization), next it introduces a proposition for 4D BIM uses implementation by project development phase, and to conclude it summarizes stakeholders roles and documents relevant to 4D BIM uses. 1 Introduction This article offers an extended version of "Identification of relevant project documents to 4D BIM uses for a synchronous collaborative Decision support" paper (Bolshakova et al., 2018). First, to complete the previous work, it describes the design approach of a 4D-based collective Decision Device. Second, in order to set a context, it overviews in more details current tendencies of digital era for AEC and a place of 4D BIM diffusion. Third, the article will summaries BIM project complexity in order to understand the current context and its limits. Next, we introduce a synchronous collaboration context. Finally, the article will review 4D BIM uses and their relevance to each phase of project development. In addition, we will close by considering project stakeholders' roles on 4D BIM uses.
