EMC Research Group

Sfax, Tunisia

EMC Research Group

Sfax, Tunisia

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Charfi W.,EMC Research Group | Masmoudi M.,EMC Research Group | Derbel F.,Communication QUNDIS GmbH
5th Conference on Design and Technology of Integrated Systems in Nanoscale Era, DTIS 2010 | Year: 2010

This paper puts forward an optimization in routing processing for wireless sensor networks. The sensor node in such network is a battery-operated sensing device. These nodes are placed in space with a consideration to a base station that centralizes and consolidates the data transmitted or forwarded by sensor nodes. When optimizing the management of a Wireless Sensor Network, we have to take care of the consumption of energy that takes place while sensor nodes are running the routing process to send or relay a message to neighbors or to a Base Station. In this paper, we put forward a study of sensors' behavior by modeling and implementing a controller with Coloured Petri Network in order to ensure the reduction of energy consumption in some sensor networks in which each node can be activated or suspended as need be. The controller must deal with activation and suspension to apply a reconfiguring policy to nodes depending on an energy supply level in every sensor in order to obtain the lowest level possible of energy consumption and maintain the same service quality consisting in total coverage of the region to survey and the connection of active nodes to the functional network. The evaluation of our presented model is made by CPN-Tools. © 2010 IEEE.

Rouabeh H.,EMC Research Group | Abdelmoula C.,EMC Research Group | Masmoudi M.,EMC Research Group
International Image Processing, Applications and Systems Conference, IPAS 2014 | Year: 2014

This paper discusses the evaluation of two supervised learning based image classification algorithms. The classification subject of this work is part of a complete vision based road sign recognition system to be implanted using the VHDL language on an FPGA card for driver assistance applications. The classification is used in order to classify road scene images into different day times according to scene illumination and weather conditions. Due to the sensitivity of colors to illumination variation, the classification task is developed to improve the red color segmentation task which presents an important level in the road sign recognition system. In order to achieve real-time processing tasks and to reduce computing time and hardware resources occupation, the performance of the two predictive modeling techniques which are Neural Networks and Decision Trees is evaluated in this work. The VHDL circuit of the Decision Tree classifier is presented as well. © 2014 IEEE.

Thabet H.,EMC Research Group | Thabet H.,Aix - Marseille University | Meillere S.,Aix - Marseille University | Masmoudi M.,EMC Research Group | And 3 more authors.
Analog Integrated Circuits and Signal Processing | Year: 2012

This paper describes a new three-stage voltage controlled ring oscillator (VCO) based on 0.35 μm standard CMOS technology. The VCO was designed for a transmitter operating in the 863-870 MHz European band for wireless sensor applications. The transmitter is designed for binary frequency-shift keying (BFSK) modulation, communicating a maximum data rate of 20 kb/s. In addition to the VCO, the transmitter combines a BFSK modulator, an up conversion mixer, a power amplifier and an 863-870 MHz band pass filter. The modulator uses the frequency hopping spread spectrum and it is intended for short range wireless applications, such as wireless sensor networks. The oscillation frequency of the VCO is controlled by a voltage V CTRL. Simulation results of the fully differential VCO with positive feedback show that the estimated power consumption, at desired oscillation frequency and under a supply voltage of 3.3 V, is only 7.48 mW. The proposed VCO exhibits a phase noise lower than -126 dBc/Hz at 10 MHz offset frequency. © 2012 Springer Science+Business Media, LLC.

Abdelmoula C.,EMC Research Group | Rouabeh H.,EMC Research Group | Masmoudi M.,EMC Research Group
International Journal of Intelligent Engineering and Systems | Year: 2013

This work describes the design and development of controllers based on artificial intelligence applied to a newly designed mobile robot type-vehicle to control behavior for monitoring wall. Two approaches have been developed and optimized to achieve this task. The first one is based on Fuzzy logic. This control algorithm combines different sensory information and provides a suitable control command allowing the mobile robot to follow the wall deviations. The second approach consists of the application of a hybrid-type Neuro-Fuzzy ANFIS controller for the same task. An important feature of this approach is that the controller combines the advantages of both Fuzzy logic and Neural Networks. The simulation results are presented and implemented with VHDL using ANFIS architecture.

Thabet H.,Aix - Marseille University | Thabet H.,EMC Research Group | Meillere S.,Aix - Marseille University | Masmoudi M.,EMC Research Group | And 3 more authors.
7th International Conference on Design and Technology of Integrated Systems in Nanoscale Era, DTIS 2012 | Year: 2012

A new Combiner architecture for direct conversion transmitter based on CMOS inverters only and operating in transconductance mode is presented in this paper. Typical applications of an adder and a subtractor of two small amplitude signals are proposed to illustrate the circuit capabilities. The proposed circuit operation has been acted from measurements with the HCC/HCF4069UB Hex Inverter from the SGS Thomson Microelectronics [1]. © 2012 IEEE.

Op't Land S.T.,EMC Research Group | Ramdani M.,EMC Research Group | Perdriau R.,EMC Research Group | Leone M.,Otto Von Guericke University of Magdeburg | Drissi M.,University Europeenne Of Bretagne Ietr
Progress in Electromagnetics Research | Year: 2013

To obtain Electromagnetic Compatibility (EMC), we would like to study the worst-case electromagnetic field-induced voltages at the ends of Printed Circuit Board (PCB) traces. With increasing frequencies, modelling these traces as electrically short no longer suffices. Accurate long line models exist, but are too complicated to easily induce the worst case. Therefore, we need a simple analytical model. In this article, we predict the terminal voltages of an electrically long, two-wire transmission line with characteristic loads in vacuum, excited by a linearly polarised plane wave. The model consists of a short line model (one Taylor cell) with an intuitive correction factor for long line effects: the modified Taylor cell. We then adapt the model to the case of a PCB trace above a ground plane, illuminated by a grazing, vertically polarised wave. For this case, we prove that end-fire illumination constitutes the worst case. We derive the worst-case envelope and try to falsify it by measurement in a Gigahertz Transverse Electromagnetic (GTEM) cell.

Nebhen J.,EMC Research Group | Nebhen J.,Aix - Marseille University | Meillere S.,Aix - Marseille University | Masmoudi M.,EMC Research Group | And 3 more authors.
Analog Integrated Circuits and Signal Processing | Year: 2013

This paper presents a CMOS voltage controlled ring oscillator with temperature compensation circuit suitable for low-cost and low-power gas sensor. To operate at low frequency, a control voltage generated by a CMOS bandgap reference is described and the measurement results of the fabricated chips are presented. The output voltage of the reference is set by resistive subdivision. In order to achieve small area and low power consumption, n-well resistors are used. This design features a reference voltage of 1 V. The chip is fabricated in AMS 0.35 μm CMOS process with an area of 0.032 mm2. Operating at 1.25 V, the output frequency is within 200 ± l0 kHz over the temperature range of -25 to 80 C with a power consumption of 810 μW. © 2013 Springer Science+Business Media New York.

Nebhen J.,Aix - Marseille University | Nebhen J.,EMC Research Group | Meillere S.,Aix - Marseille University | Masmoudi M.,EMC Research Group | And 3 more authors.
7th International Conference on Design and Technology of Integrated Systems in Nanoscale Era, DTIS 2012 | Year: 2012

In this paper, a low-noise, low-power and low voltage Chopper Stabilized CMOS Amplifier (CHS-A) is presented and simulated using transistor model parameters of the AMS 0.35 m CMOS process. Chopping is used to modulate the offset away from the output signal where it can be easily filtered out, providing continuous offset reduction which is insensitive to drift. The CHS was simulated using typical transistor model parameters BSIM 3V3 of the 0.35 μm CMOS process technology from AMS [1]. Under at ±1.25 V power supply and a voltage gain of 49dB, the total power consumption is 250 μW only. At the same simulation condition, it achieves a noise floor of 0.194 nV/√Hz within the frequency range from 1 kHz to 10 kHz and the inband PSRR is above 90, the CMRR exceeds 120 dB. The circuit occupies an effective small chip area of 3.233 mm2. © 2012 IEEE.

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