Abdelmoula Bekkali

Transmission analysis of digital TV signals over a Radio-on-FSO channel

Recently, radio-on-free-space optical (RoFSO) technology is regarded as a new universal platform for enabling seamless convergence of fiber and FSO communication networks, thus extending broadband connectivity to underserved areas. In this article, an experimental demonstration of the newly developed advanced RoFSO system capable of transmitting the Japanese integrated services digital broadcasting- terrestrial (ISDB-T) signals over a 1 km FSO link is presented. Our innovative system combines a new generation full optical FSO system with radio over fiber technology. Important performance quality metrics like the modulation error ratio and bit error rate are measured and analyzed to characterize the deployment environment influencing the transmission of ISDB-T signals over the FSO link. The obtained results can be used for designing, predicting, and evaluating the RoFSO system capable of transmitting multiple wireless services over turbulent FSO links.

Visible Light Communication for Vehicular Networking: Performance Study of a V2V System Using a Measured Headlamp Beam Pattern Model

In this article, we discuss visible light communication (VLC) in the context of vehicular communication networks. With the omnipresence of light-emitting diodes (LEDs) in outdoor and automotive lightings, VLC emerges as a natural candidate for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. We first provide an overview of this emerging research area highlighting recent advances and identifying open problems for further research. Then, we present the performance evaluation of a typical V2V VLC system with realistic automative light sources. Our evaluation takes into account the measured headlamp beam pattern and the impact of road reflected light. We demonstrate that depending on the photodetector (PD) position above the ground level, a data rate of 50 Mb/s can be achieved at 70 m.

Performance Analysis of Passive UHF RFID Systems Under Cascaded Fading Channels and Interference Effects

In this paper, the performance of monostatic and bistatic passive ultra high frequency radio frequency identification (UHF RFID) systems under the effects of cascaded fading channels and interference is studied. The performance metric used is tag detection probability defined as the probability that the instantaneous received power is higher than the readers sensitivity. A closed-form expression of the detection probability is derived using cascaded forward and backscatter fading channels and the reader antennas orientation relative to the tag. Furthermore, the performance of passive UHF RFID systems under reader-to-tag interference caused by both the desired RFID signal and multiple RFID interferers is analyzed, and the effect of constructive and destructive interferences is examined. In addition, the maximum reading range in ideal, multipath fading, and interfering environments is presented. To the best of our knowledge, this is the first work that provides a 3-D performance analysis of the passive UHF RFID systems under cascaded fading channels. The obtained results are very useful for the design and optimization of passive UHF RFID systems from an RF physical channel point of view.

Bayesian sensor model for indoor localization in Ubiquitous Sensor Network

Ubiquitous sensor networks (USN) technology is one of the essential key for driving the next generation network (NGN) to realize secure and easy access from anyone, any thing, anywhere and anytime. The location information is one of the most important and frequently-used contexts in ubiquitous networking. However, a system can use the changes of location to adapt its behavior, such as computation and communication, without the user intervention. In this paper we introduce a Bayesian sensor framework for solving the location estimation errors problem in Radio Frequency Identification (RFID) environments. In our model the physical properties of the signal propagation are not taken into account directly. Instead, the location estimation is regarded as machine learning problem in which the task is to model how the location estimation error is distributed indoors based on a sample of measurements collected at several known locations and stored in RFID tags. Results obtained by simulations demonstrate the suitability of the proposed model to provide high performance level in terms of accuracy and scalability.

Seamless convergence of radio-over-fiber and millimeter-wave links for highly resilient access networks

Seamless integration of optical fiber and wireless transmission systems using coherent radio-over-fiber (CRoF) technique is a promising solution for highly resilient and agile communication systems, where high-capacity millimeter wave (mmWave) links can conveniently be used as fiber backup to bolster the network resiliency while satisfying the requirements of both high capacity and long transmission distance. In this paper, we introduce and experimentally validate a comprehensive optimization framework for photonic generation of mmWave signals based on dual-parallel Mach-Zehnder modulator (DP-MZM) with unbalanced power splitting ratio. The derived values provide high sub-harmonics suppression ratio while maximizing the conversion efficiency. Moreover, we demonstrate and evaluate the transmission of 5-Gbaud QPSK signal over seamless RoF and W-band mmWave (75-110 GHz) wireless links. We also investigate the impact of the W-band wireless section link loss, W-band devices characteristics and the mmWave down-conversion intermediate frequency (IF) selection on the overall system performance. The obtained results will enable us to design a seamless mmWave-RoF transmission system in practical scenarios and also confirm the potential use of the system for next generation agile and resilient optical access networks.

Real-Time 10GbE Data Transmission Over a Converged RoF Links and 96-GHz Wireless Bridge

In this letter, we present a proof-of-concept of a realtime 10-Gigabit Ethernet (10GbE) standard data connectivity over a seamlessly converged intermediate frequency IF-overfiber and millimeter wave links with remotely fed optical local oscillator (LO) signals. We demonstrate an error-free real-time transmission of π/4-DQPSK-mapped 10GbE frames at 5-Gbit/s over 2×20-km single mode fiber and 20-m W-band (i.e., 96 GHz) wireless bridge. The 10GbE traffic is adjusted to the actual system capacity and transmitted using two parallel channels with a maximum rate of 1.25-GBaud per channel. We experimentally investigate and evaluate the impact of RoF and W-band links characteristics on the overall system performance. The obtained results demonstrate the potential use of the proposed system for the next generation agile and resilient access networks.

Tag read enhancement using unsynchronized signal from adjacent readers in multi-cell RFID system

This paper addresses the interference issue in a passive multi-cell radio frequency identification (RFID) system. Instead of considering the negative effect of interfering RF signals from adjacent readers, we investigate its constructive effect in providing extra RF power to tags in the cell of the desired reader system. Through detailed simulation and experimental analysis, it is found that the unsynchronised signal from neighbouring readers can be utilized to activate marginal tags through enhancing power delivery. This results in improved tag received signal strength indicator (RSSI). In addition, it is found that the overlap zone between two RFID cells is not as vulnerable to interference as one might think. In fact, the adjacent reader may facilitate the desired reader to read more tags in the overlapping zone, although a longer inventory period may be required. We believe these findings might provide a new insight into the interference effect on multi-cell RFID system and be applied to future medium access control (MAC) protocols.

Performance evaluation of real-time 10GbE data connectivity over a converged IF-over-Fiber links and millimeter-wave wireless bridge

In in this paper, we present a proof-of-concept of a real-time 10GbE standard data connectivity and ultra-highdefinition (UHD) video streaming over a seamlessly converged intermediate frequency (IF)-over fiber (IFoF) and millimeter-Wave (mmWave) links. We successfully transmit π/4-DQPSK mapped Ethernet frames at 4.6 Gbps capacity over 2×20-km single mode fiber (SMF) links and 20-m W-band (i.e. 96-GHz) wireless bridge. We also demonstrate an error-free live steaming of 36 compressed 8K UHD videos with a total data-rate of 4.3 Gbps. Moreover, the impact of IFoF and W-band links characteristics on the system performance is experimentally investigated and evaluated. Based on the proposed system performance, we further estimate the achievable W-band transmission distance for both fair and heavy rain weather conditions. The obtained results confirm the potential use of mmWave-IFoF links for reliable high bandwidth GbE data connectivity, in particular for applications such as quick disaster recovery, temporary dense communication area, and large-scale live relay broadcasting of UHD-TV programs.

Performance of Passive UHF RFID in Cascaded Correlated Generalized Rician Fading

Ultra high frequency radio frequency identification (UHF RFID) systems can use passive tags to reflect the signal from the readers transmitting antenna back to the readers receiving antenna for information delivery. This gives a cascaded channel that is a product of two fading components. In this work, the probability of detection, defined as the probability that the received power is above the receiver sensitivity, is derived when the two fading components suffer from correlated generalized Rician fading. This includes the Rayleigh, Rician, and Nakagami-

Impact of reader-to-tag interference and forward link fading on RFID system performance

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