Danielle Janvier - Academia.edu (original) (raw)
Papers by Danielle Janvier
IEE Proceedings - Microwaves, Antennas and Propagation, 1995
... 55, no. 8, Aug. 2008. [10] M. Emam, P. Sakalas, D. Vanhoenacker-Janvier, J.-P. Raskin, TC Lim... more ... 55, no. 8, Aug. 2008. [10] M. Emam, P. Sakalas, D. Vanhoenacker-Janvier, J.-P. Raskin, TC Lim, and F. Danneville, Experimental Investigation of RF Noise Performance Improvement in Graded Channel MOSFETs, IEEE Trans. Electron Devices, vol. 56, no. 7, pp. ...
this paper presents the validation of an electromagnetic radar simulator based on Large Eddy Simu... more this paper presents the validation of an electromagnetic radar simulator based on Large Eddy Simulations of the turbulent atmosphere. The simulator has been developed by UCL in the frame of the FP7 UFO project aimed at improving the Wake-Vortex Advisory Systems by the analysis, design and development of innovative technologies for Ultra-Fast Radar and Lidar used as wind and Eddy Dissipation Rate sensors. Experimental trials have taken place at Toulouse airport giving access to concurrent collocated X-band radar data and meteorological data. The simulator is validated against radar and meteorological values of Eddy Dissipation Rate, showing a good agreement, with a trend to have meteorological values somewhat higher than radar measured and simulated values.
This paper describes a deterministic model which simulates the radiowave propagation for UMTS in ... more This paper describes a deterministic model which simulates the radiowave propagation for UMTS in urban areas. The model is based on a UTD ray-tracing tool, using the mirror method. Meanwhile, channel impulse responses (CIRs) have been measured in order to validate the ray-tracing tool. Measurements have been carried out at 1.87 GHz in a street of Louvain-la-Neuve (Belgium) by means of a wideband channel sounder. Simulated and experimental results are presented and compared quite satisfactorily in spite of several limitations.
2021 15th European Conference on Antennas and Propagation (EuCAP)
Due to the congestion of the electromagnetic spectrum and the need for larger bandwidths, space r... more Due to the congestion of the electromagnetic spectrum and the need for larger bandwidths, space radio-communication systems are moving towards the use of higher frequency bands (Ka, Q/V and W bands). These frequencies are severely impaired by atmospheric phenomena causing attenuation, scintillation and depolarization. This paper introduces a new propagation experiment that will extend the characterization of the Earth-space channel up to the W band and low Earth orbits (LEO). The satellite launch is planned for 2021, followed by a measurement campaign lasting two years.
IEEE Transactions on Vehicular Technology, 2002
To evaluate the performance of future microcellular IMT-2000 modems, simple physical models are r... more To evaluate the performance of future microcellular IMT-2000 modems, simple physical models are required, so that a number of system characteristics, such as the signal bandwidth, the antenna beamwidth, or the base station height can be accounted for at a limited computational cost. This paper describes a deterministic three-dimensional electromagnetic model, which allows simulation of the radiowave propagation for microcellular wide-band communication systems in urban areas. The model is based on a UTD ray-tracing tool and makes use of an improved mirror method. Simulated power-delay profiles are plotted against measured power-delay profiles recorded at 1.87 GHz in a street of Louvain-la-Neuve, Belgium, by means of an 80-MHz channel sounder. Despite several discrepancies, a satisfying matching is found considering three orders of reflection and single diffraction. Predictions of rms delay-spread accounting for the sounder limited bandwidth are presented. Finally, simulated and measured channels are also compared through the resulting performance of a typical IMT-2000 service in the presence of multiple access interference. Index Terms-Communication system performances, ray tracing, wide-band radio channel measurements.
International Journal of Satellite Communications and Networking
International Journal of Satellite Communications and Networking
IEEE Transactions on Antennas and Propagation
A new model has been developed for the calculation of the radar cross section and the power backs... more A new model has been developed for the calculation of the radar cross section and the power backscattered by wake vortices of take-off and landing airplanes in order to better understand the physical mechanisms involved, to compare with the measurements that will be performed in X-band by Thales during the SESAR P12.2.2 project and to prepare inputs for testing a Wake Vortex Advisory System. The model contains a first part that simulates the evolution of the vortex in stratified atmosphere, using simplified 2D fluid mechanics equations and uses the pressure, temperature and humidity for the calculation of the difference between the dielectric permittivity of the clear air and of the wake vortex. The second part calculates the power backscattered by the dielectric permittivity gradients in the vortex. The input parameters describe the atmosphere as well as the airplane of interest. Simulation results have been compared with results published in the literature, when all the input para...
International Journal of Artificial Intelligence in Education
Microwaves propagation modelling in clear air troposphere i.e. without rain is investigated. Larg... more Microwaves propagation modelling in clear air troposphere i.e. without rain is investigated. Large scale variations of refractivity are computed from mesoscale meteorological modelling. Small scale variations are deduced from large scale considering that the inertial regime of Kolmogorov spectrum is established. The propagation effects are estimated applying launching ray to take into account large scale refractivity effects and resolution of Parabolic Wave Equation with Multiple Phase Screen technique for small scale. The proposed approach has been evaluated versus earth satellite measurements of log-amplitude scintillation measured at Louvain-la-Neuve.
International Journal of Artificial Intelligence in Education
In this paper we present an enhanced version of previous narrowband land mobile satellite, LMS, c... more In this paper we present an enhanced version of previous narrowband land mobile satellite, LMS, channel models. Some of the shortcomings of the previous models have been identified and corrections proposed. The model is well suited for generating synthetic time-series.
This paper presents the study carried out to design and develop an archive of propagation measure... more This paper presents the study carried out to design and develop an archive of propagation measurements. The goal of this action was to be able to keep measured datasets in good shape, because due to the rapid changing situation in the telecommunication sector, some of the datasets may become unavailable. This will be damageable since these datasets are of very
2010 IEEE International SOI Conference (SOI), 2010
Abstract In this work electrical properties of GC SOI nMOSEETs from two different technologies we... more Abstract In this work electrical properties of GC SOI nMOSEETs from two different technologies were presented for temperatures ranging between 90K and 380K. It has been shown that the increase of mobility with temperature reduction is larger than for devices with lighter dopind levels. Heavily doped GC from transistors shown constant threshold voltage over the entire temperature range, as it lies close to the ZTC point. Although the temperature lowering leads devices to operate in full depletion, GC devices with thin gate oxide ...
IEEE International Conference on Communications, 2003. ICC '03., 2003
Spatial multiplexing is employed in MIMO communication systems to increase spectral efficiency. T... more Spatial multiplexing is employed in MIMO communication systems to increase spectral efficiency. The performance of spatial multiplexing is highly dependent on the propagation conditions such as the richness of scattering, the presence of dominant components and the inter-element spacings. In this paper, new robust signal constellations for use in spatial multiplexing over real fading propagation channels are developed. It is
IEEE International Conference on Communications, 2003. ICC '03., 2003
... 1. Each radiation pattern is expressed in its own coordinate system. Fig. ... MA Beach and PN... more ... 1. Each radiation pattern is expressed in its own coordinate system. Fig. ... MA Beach and PN Fletcher, Experimental investigation into the impact of mutual coupling on MIMO communications systems ... [5] J. Luo, JR Zeidler and S. McLaughlin, Performance analysis of compact ...
IEEE 60th Vehicular Technology Conference, 2004. VTC2004-Fall. 2004, 2004
Linear dispersion codes (LDC) are high-rate codes that exploit both the spectral efficiency and t... more Linear dispersion codes (LDC) are high-rate codes that exploit both the spectral efficiency and the diversity a multiple-input multiple-output (MIMO) system may offer. However they are complex to design for high spectral efficiency and their designs have been limited to the case of independent and identically Rayleigh distributed (i.i.d.) channels. In this paper we design channel correlation based LDC under
VTC-2005-Fall. 2005 IEEE 62nd Vehicular Technology Conference, 2005., 2005
Space-time code designs commonly rely on the assumption of independent and identically distribute... more Space-time code designs commonly rely on the assumption of independent and identically distributed (i.i.d.) Rayleigh channels. However channel measurements have shown that real-world channels are spatially correlated. In this paper, we study the impact of spatial correlation on the performance of space-time codes evolving in fast Rayleigh fading channels. It is shown that transmit correlation may highly affect the achievable diversity if the code is not properly designed. Therefore, we propose a new design criterion that subsumes the original design criterion developed by Tarokh et al. and leads to space-time codes that are robust in a wide variety of propagation conditions. No channel knowledge is assumed at the transmitter. Codes satisfying this criterion are shown to be much more robust on spatially correlated fast fading channels than codes designed only for i.i.d. fast fading channels. Examples of Space-Time Trellis Codes are proposed in order to illustrate the design criterion.
IEE Proceedings - Microwaves, Antennas and Propagation, 1995
... 55, no. 8, Aug. 2008. [10] M. Emam, P. Sakalas, D. Vanhoenacker-Janvier, J.-P. Raskin, TC Lim... more ... 55, no. 8, Aug. 2008. [10] M. Emam, P. Sakalas, D. Vanhoenacker-Janvier, J.-P. Raskin, TC Lim, and F. Danneville, Experimental Investigation of RF Noise Performance Improvement in Graded Channel MOSFETs, IEEE Trans. Electron Devices, vol. 56, no. 7, pp. ...
this paper presents the validation of an electromagnetic radar simulator based on Large Eddy Simu... more this paper presents the validation of an electromagnetic radar simulator based on Large Eddy Simulations of the turbulent atmosphere. The simulator has been developed by UCL in the frame of the FP7 UFO project aimed at improving the Wake-Vortex Advisory Systems by the analysis, design and development of innovative technologies for Ultra-Fast Radar and Lidar used as wind and Eddy Dissipation Rate sensors. Experimental trials have taken place at Toulouse airport giving access to concurrent collocated X-band radar data and meteorological data. The simulator is validated against radar and meteorological values of Eddy Dissipation Rate, showing a good agreement, with a trend to have meteorological values somewhat higher than radar measured and simulated values.
This paper describes a deterministic model which simulates the radiowave propagation for UMTS in ... more This paper describes a deterministic model which simulates the radiowave propagation for UMTS in urban areas. The model is based on a UTD ray-tracing tool, using the mirror method. Meanwhile, channel impulse responses (CIRs) have been measured in order to validate the ray-tracing tool. Measurements have been carried out at 1.87 GHz in a street of Louvain-la-Neuve (Belgium) by means of a wideband channel sounder. Simulated and experimental results are presented and compared quite satisfactorily in spite of several limitations.
2021 15th European Conference on Antennas and Propagation (EuCAP)
Due to the congestion of the electromagnetic spectrum and the need for larger bandwidths, space r... more Due to the congestion of the electromagnetic spectrum and the need for larger bandwidths, space radio-communication systems are moving towards the use of higher frequency bands (Ka, Q/V and W bands). These frequencies are severely impaired by atmospheric phenomena causing attenuation, scintillation and depolarization. This paper introduces a new propagation experiment that will extend the characterization of the Earth-space channel up to the W band and low Earth orbits (LEO). The satellite launch is planned for 2021, followed by a measurement campaign lasting two years.
IEEE Transactions on Vehicular Technology, 2002
To evaluate the performance of future microcellular IMT-2000 modems, simple physical models are r... more To evaluate the performance of future microcellular IMT-2000 modems, simple physical models are required, so that a number of system characteristics, such as the signal bandwidth, the antenna beamwidth, or the base station height can be accounted for at a limited computational cost. This paper describes a deterministic three-dimensional electromagnetic model, which allows simulation of the radiowave propagation for microcellular wide-band communication systems in urban areas. The model is based on a UTD ray-tracing tool and makes use of an improved mirror method. Simulated power-delay profiles are plotted against measured power-delay profiles recorded at 1.87 GHz in a street of Louvain-la-Neuve, Belgium, by means of an 80-MHz channel sounder. Despite several discrepancies, a satisfying matching is found considering three orders of reflection and single diffraction. Predictions of rms delay-spread accounting for the sounder limited bandwidth are presented. Finally, simulated and measured channels are also compared through the resulting performance of a typical IMT-2000 service in the presence of multiple access interference. Index Terms-Communication system performances, ray tracing, wide-band radio channel measurements.
International Journal of Satellite Communications and Networking
International Journal of Satellite Communications and Networking
IEEE Transactions on Antennas and Propagation
A new model has been developed for the calculation of the radar cross section and the power backs... more A new model has been developed for the calculation of the radar cross section and the power backscattered by wake vortices of take-off and landing airplanes in order to better understand the physical mechanisms involved, to compare with the measurements that will be performed in X-band by Thales during the SESAR P12.2.2 project and to prepare inputs for testing a Wake Vortex Advisory System. The model contains a first part that simulates the evolution of the vortex in stratified atmosphere, using simplified 2D fluid mechanics equations and uses the pressure, temperature and humidity for the calculation of the difference between the dielectric permittivity of the clear air and of the wake vortex. The second part calculates the power backscattered by the dielectric permittivity gradients in the vortex. The input parameters describe the atmosphere as well as the airplane of interest. Simulation results have been compared with results published in the literature, when all the input para...
International Journal of Artificial Intelligence in Education
Microwaves propagation modelling in clear air troposphere i.e. without rain is investigated. Larg... more Microwaves propagation modelling in clear air troposphere i.e. without rain is investigated. Large scale variations of refractivity are computed from mesoscale meteorological modelling. Small scale variations are deduced from large scale considering that the inertial regime of Kolmogorov spectrum is established. The propagation effects are estimated applying launching ray to take into account large scale refractivity effects and resolution of Parabolic Wave Equation with Multiple Phase Screen technique for small scale. The proposed approach has been evaluated versus earth satellite measurements of log-amplitude scintillation measured at Louvain-la-Neuve.
International Journal of Artificial Intelligence in Education
In this paper we present an enhanced version of previous narrowband land mobile satellite, LMS, c... more In this paper we present an enhanced version of previous narrowband land mobile satellite, LMS, channel models. Some of the shortcomings of the previous models have been identified and corrections proposed. The model is well suited for generating synthetic time-series.
This paper presents the study carried out to design and develop an archive of propagation measure... more This paper presents the study carried out to design and develop an archive of propagation measurements. The goal of this action was to be able to keep measured datasets in good shape, because due to the rapid changing situation in the telecommunication sector, some of the datasets may become unavailable. This will be damageable since these datasets are of very
2010 IEEE International SOI Conference (SOI), 2010
Abstract In this work electrical properties of GC SOI nMOSEETs from two different technologies we... more Abstract In this work electrical properties of GC SOI nMOSEETs from two different technologies were presented for temperatures ranging between 90K and 380K. It has been shown that the increase of mobility with temperature reduction is larger than for devices with lighter dopind levels. Heavily doped GC from transistors shown constant threshold voltage over the entire temperature range, as it lies close to the ZTC point. Although the temperature lowering leads devices to operate in full depletion, GC devices with thin gate oxide ...
IEEE International Conference on Communications, 2003. ICC '03., 2003
Spatial multiplexing is employed in MIMO communication systems to increase spectral efficiency. T... more Spatial multiplexing is employed in MIMO communication systems to increase spectral efficiency. The performance of spatial multiplexing is highly dependent on the propagation conditions such as the richness of scattering, the presence of dominant components and the inter-element spacings. In this paper, new robust signal constellations for use in spatial multiplexing over real fading propagation channels are developed. It is
IEEE International Conference on Communications, 2003. ICC '03., 2003
... 1. Each radiation pattern is expressed in its own coordinate system. Fig. ... MA Beach and PN... more ... 1. Each radiation pattern is expressed in its own coordinate system. Fig. ... MA Beach and PN Fletcher, Experimental investigation into the impact of mutual coupling on MIMO communications systems ... [5] J. Luo, JR Zeidler and S. McLaughlin, Performance analysis of compact ...
IEEE 60th Vehicular Technology Conference, 2004. VTC2004-Fall. 2004, 2004
Linear dispersion codes (LDC) are high-rate codes that exploit both the spectral efficiency and t... more Linear dispersion codes (LDC) are high-rate codes that exploit both the spectral efficiency and the diversity a multiple-input multiple-output (MIMO) system may offer. However they are complex to design for high spectral efficiency and their designs have been limited to the case of independent and identically Rayleigh distributed (i.i.d.) channels. In this paper we design channel correlation based LDC under
VTC-2005-Fall. 2005 IEEE 62nd Vehicular Technology Conference, 2005., 2005
Space-time code designs commonly rely on the assumption of independent and identically distribute... more Space-time code designs commonly rely on the assumption of independent and identically distributed (i.i.d.) Rayleigh channels. However channel measurements have shown that real-world channels are spatially correlated. In this paper, we study the impact of spatial correlation on the performance of space-time codes evolving in fast Rayleigh fading channels. It is shown that transmit correlation may highly affect the achievable diversity if the code is not properly designed. Therefore, we propose a new design criterion that subsumes the original design criterion developed by Tarokh et al. and leads to space-time codes that are robust in a wide variety of propagation conditions. No channel knowledge is assumed at the transmitter. Codes satisfying this criterion are shown to be much more robust on spatially correlated fast fading channels than codes designed only for i.i.d. fast fading channels. Examples of Space-Time Trellis Codes are proposed in order to illustrate the design criterion.