Aliou Bamba

Ecole Supérieure Africaine des Technologies de l'Information et de la Communication (ESATIC) · Direction de la Recherche et de l'Innovation Technologique (DRIT)

This article explores the use of social networks by workers in Abidjan, Côte d'Ivoire, with particular emphasis on a descriptive or quantitative analysis aimed at understanding motivations and methods of use. More than five hundred and fifty questionnaires were distributed, highlighting workers' preferred digital channels and platforms. The results...

Free-space optical communication (FSO) systems refer to the high-speed transmission of point to point data using laser beams in vacuum, space or air. They have their performance levels limited under different weather conditions. To carry out this study, we collected monthly weather data for Abidjan from January 2018 to December 2022 on the website...

Dissipative light bullets can be considered as (3+1) D spatiotemporal dynamics of stable optical solitons in the three spatial dimensions, in addition to localization in the temporal domain. They share many common characteristics with other multi-dimensional phenomena and their study remain an open challenge. Here, we report semi-rotating and rotat...

This paper investigates the social networks usage by students in Abidjan city, Côte d'Ivoire. We focus on a descriptive or quantitative analysis to understand the motivations and how students make use of internet and social networks. More than six hundred forms were distributed to persons we have deemed as students. In return, we received more than...

Free space optical communication (FSO) systems have their performance levels limited under different atmospheric conditions. Thus, the characteri- zation of the transmission channel plays an important role in the analysis of the FSO link performance. This research work focuses on the analysis of the transmission performance of Free Space Optical (F...

In wireless networks, propagation models are used to assess the received power signal and estimate the propagation channel. These models depend on the pathloss exponent (PLE) which is one of the main parameters to characterize the propagation environment. Indeed, in the wireless channel, the path loss exponent has a strong impact on the quality of...

The characteristics of multipath components (MPCs) are addressed in an industrial environment at 1.3 GHz by means of measurements with a multidimensional channel sounder. The maximum likelihood estimator, RiMAX, is used to determine the MPCs parameters and takes into account the diffuse scattering. Both line‐of‐sight (LOS) and obstructed LOS (OLOS)...

In this study, we showed that the propagating electromagnetic wave (EMW) in the human body tissue is affected by the medium parameters such as the permittivity, conductivity, and permeability. We used an inversed F-antenna (IFA) and Notch antenna to investigate the effects of radio-frequency (RF) and millimeter-wave (mmWave) radiation on the human'...

A semianalytical method to study the effects of the higher-order spectral filtering in the cubic-quintic complex Swift-Hohenberg equation (CSHE) through the dynamics of one soliton was applied. The approach is based on a reduction from an infinite-dimensional dynamical dissipative system to a finite-dimensional model. This formulation is helpful to...

This paper presents a benchmarking analysis of wideband channel characteristics in two indoor environments in the 59-65 GHz and 80.5-86.5 GHz bands. Measurements were carried out by performing mechanical steering of directive antennas at both the transmitter and receiver sides. Omnidirectional power delay profiles were obtained from directional mea...

This paper analyzes the frequency dependency of the radio propagation channel's root mean square (rms) delay spread (DS), based on the multi-frequency measurement campaigns in the mmMAGIC project. The campaigns cover indoor, outdoor, and outdoor-to-indoor (O2I) scenarios and a wide frequency range from 2 to 86 GHz. Several requirements have been id...

This paper presents a physical-statistical radio channel power delay profiles model for room-to-room communication systems combining the Room Electromagnetic Theory for modeling deterministic channel components with a geometry based stochastic channel model with time-variant statistics for modeling stochastic components. The deterministic channel c...

This deliverable describes the extensive multi-frequency channel measurement and simulation campaigns conducted in the mmMAGIC project, covering mm-wave 5G propagation scenarios. The data is evaluated to characterize environment-specific propagation effects. Based on the findings, refined modelling approaches are developed and embedded in a geometr...

This paper presents wideband channel measurements in an office environment in the 62 GHz and 83 GHz frequency bands. Measurements were performed with a VNA and the mechanical steering of directive antennas at both the transmitter and receiver side, allowing a double-directional angular characterization. A comparison of propagation characteristics s...

For the first time, response of personal exposimeters (PEMs) is studied under diffuse field exposure in indoor environments. To this aim, both numerical simulations, using finite-difference time-domain method, and calibration measurements were performed in the range of 880–5875 MHz covering 10 frequency bands in Belgium. Two PEMs were mounted on th...

The response of personal exposimeters (PEMs) is studied under diffuse field exposure in indoor environments. A numerical model and a setup for on-body calibration measurements in a reverberation chamber (RC) is proposed for 897-5500 MHz. The proposed numerical simulations are in good agreement with measurements. A difference around 2 dB between the...

A fast method to assess radiofrequency (RF) radiation absorption in humans present in realistic indoor environments is proposed. The only required inputs are the room characteristics and the weight and position of the human with respect to the electromagnetic source. The method is compared and validated with full finite-difference time-domain simul...

A simple formula to determine the human average whole-body SAR (SARwb) under realistic propagation conditions is proposed in the GHz region, i.e. from 1.45 GHz to 5.8 GHz. The methodology is based on simulations of ellipsoidal human body models. Only the exposure (incident power densities) and the human mass are needed to apply the formula. Diffuse...

The electromagnetic reverberation time characteristics are investigated at UltraWide Band (UWB) frequencies, i.e., from 2 to 10 GHz. The reverberation time is bandwidth independent and decreases as the frequency increases. Besides, the reverberation ratio - the contribution of the diffuse fields in the total power - is addressed as well. The reverb...

The electromagnetic reverberation time characteristics of indoor environments are experimentally investigated from 2 to 10 GHz. At a given frequency, the reverberation time is observed to be approximately constant for bandwidths up to 900 MHz (or larger). Moreover, the reverberation time decreases for increasing frequencies. Based on the theory of...

The reverberation time has been measured in a reverberation chamber for different loads and for a cross polarized transceiver at the frequency of 1.8 GHz. We determine the whole-body absorption cross section of a canonical phantom using a maximum-likehood high-resolution channel parameters estimator - RiMAX - and good agreement has been obtained wi...

We present a room electromagnetics-based theory which primarily models the diffuse multipath components (DMC) power density with a simple circuit model, and afterwards includes the line-of-sight (LOS) component to predict the total exposure in a realistic environment. Given a human absorption cross section (ACS) and its location from a transmitter...

Experimentally assessing the whole-body specific absorption rate (SAR(wb) ) in a complex indoor environment is very challenging. An experimental method based on room electromagnetics theory (accounting only the line-of-sight as specular path) is validated using numerical simulations with the finite-difference time-domain method. Furthermore, the me...

In this work, we developed an analytical estimation of the performance loss due to multipath propagation for a narrowband OFDM system. The propagation characteristics required for this loss estimation, are experimentally determined by virtual SIMO measurements in a large conference room where repeated reception problems were reported for an IEEE 80...

A closed room environment is viewed as a lossy cavity, characterized by possibly a line-of-sight component and diffuse scattering parts from walls and internal obstacles. A theory used in acoustics and reverberation chambers is applied for the electromagnetic case, and main issues related to measurement systems, antennas characteristics, diffuse en...

A simple theory based on room electromagnetics theory is presented. The theory primarily models the Diffuse Multipath Components (DMC) power density with a simple circuit model, and afterwards include the Line-Of-sight component (LOS) in order to determine the whole-body absorption rate for Ultra-Wide-Band (UWB) systems. The model may be very usefu...

Room electromagnetics theory is applied to determine the influence of the diffuse multipath components (DMC) in the human specific absorption rate at 2.8 GHz. The whole-body absorption is determined for an exposure to a Line Of Sight (LOS) component plus the DMC. Both experimental and numerical results show that the contribution of the DMC in the w...

A closed room environment is viewed as a lossy cavity, characterized by possibly a line of sight (LOS) component and diffuse scattering parts from walls and internal obstacles. A theory used in acoustics and reverberation chambers is applied for the electromagnetics case, and main issues related to measurement systems and antennas characteristics a...

A closed room environment is viewed as a lossy cavity, characterized by possibly a line of sight (LOS) component and diffuse scattering parts from walls and internal obstacles. A theory used in acoustics and reverberation chambers is applied for the electromagnetics case, and main issues related to measurement systems and antennas characteristics a...