Nacer Abouchi | CPE Lyon (original) (raw)

Papers by Nacer Abouchi

La complexite des reseaux de communications, qu'ils soient locaux ou etendus, ne peut etre mo... more La complexite des reseaux de communications, qu'ils soient locaux ou etendus, ne peut etre modelisee que partiellement par les methodes mathematiques existantes. L'analyse des performances et du comportement des reseaux etendus en fonction des techniques de routage adaptatifs est encore mal maitrisee. De meme, il peut etre utile d'etudier quantitativement les techniques d'acces aux reseaux locaux en fonction de leur configuration ou de leur utilisation. La simulation aleatoire a evenement discret est une solution qui peut prendre en compte toutes les specifications d'un reseau sans les simplifier, il existe encore peu d'outils specialises dans la simulation de reseaux. Dans une premiere partie, apres avoir evoque les roles de la modelisation et de la simulation dans les systemes notamment les systemes de communications, nous presentons les principaux criteres qu'il faut etudier afin de pouvoir faire un choix correct d'outil de modelisation et de simulation; une etude comparative des outils les plus utilises est presentees. La presentation des modeles de simulations que nous avons concu pour representer les reseaux de communications locaux et etendus fait l'objet du deuxieme chapitre. La troisieme partie sera consacree a "OSIRES",· l'outil de simulation de reseaux que nous avons developpe. Notre etude est poursuivie par l'analyse des differents algorithmes de routages deterministes ou adaptatifs rencontres dans des reseaux existants ou proposes dans la litterature. Dans une derniere partie les techniques d'acces aux reseaux locaux retenues par l'OSI sont analysees et comparees. Nous concluons ce memoire par les perspectives et les suites a donner a ce travail.

HAL (Le Centre pour la Communication Scientifique Directe), Sep 12, 2002

... PAU RAYONNEMENT IONISANTS GEMPPM* * * PHYSIQUE DE LA MATIERE PRODUCTIQUE ET INFORMATIQUE DES ... more ... PAU RAYONNEMENT IONISANTS GEMPPM* * * PHYSIQUE DE LA MATIERE PRODUCTIQUE ET INFORMATIQUE DES SYSTEMES MANUFACTU-RIERS PHYSIQUE DE LA MATIERE LAEPSI* * ** MODELISATION ... Min, emèrite) ROUBY D. ROUX JJ RUBEL P. RUMELHART ...

International Journal of Sensor Networks and Data Communications, 2016

Remote patient monitoring enables medical facilities and personnel to monitor patients outside of... more Remote patient monitoring enables medical facilities and personnel to monitor patients outside of conventional clinical settings. This technology is greatly affected by the available energy sources. The limited energy supply is the bottleneck for measurement, data transmission, network connection and lifetime. Thus, efficient power consumption estimation in the early stage of the design would give the user an insight on its feasibility within medical constraints. In this paper, a power-oriented Matlab based design tool is proposed. It will help the user to make an energy aware design. In fact, it will enable him to determine the power consumption of each node based on a set of selected components, the daily routine of the patient and many other factors. It will also allow him to test multiple configurations prior to the physical implementation. This will minimize the time and financial impact of any modification. Furthermore, it will provide guidance to properly adapt the design within the requirements of the application: Choosing components, energy sources, etc. A validation is proposed via a physical implementation in order to compare the results obtained through simulation with practical measurements. Future works aim to take into account memory access operations, include several sensors operating within a network, and adapt the tool to other applications (smart buildings, environmental monitoring, etc.).

ABSTRACT Complexity of communication networks, such as LANs or MANs, can only be partially descri... more ABSTRACT Complexity of communication networks, such as LANs or MANs, can only be partially described by the means of mathematical modeling theory. Performance and comportment analysis function of adaptative routing is not yet accurate. We propose a modelling tool based on SLAM language. After giving the links between a network structure and SLAM facilities, we give an application example for modelling and analysis of a packet switched communication network

ABSTRACT A novel circuit for an analog multiplier in a standard CMOS process is described. It is ... more ABSTRACT A novel circuit for an analog multiplier in a standard CMOS process is described. It is based on a two-current conveyors cell associated with a four MOSFET transconductor. This differential multiplier achieves a bandwidth of 80 MHz with a total harmonic distortion of two percents, because of the use of high-frequency current conveyors

Proceedings of SPIE, Feb 17, 1995

ABSTRACT Performance evaluation of access methods for Local Area Networks (LAN), can only be part... more ABSTRACT Performance evaluation of access methods for Local Area Networks (LAN), can only be partially studied by the mean of classical mathematical methods. Random simulation, based on discrete events, can take into account all the specifications without simplifying them. A study of the simulation language SLAM has demonstrated that this tool can be easily studied for this kind of problem. The first part of the paper will deal with a short description of SLAM facilities. In the second part, we will discuss of the modelling of the most common used methods for access control for LAN, token-passing and CSMA/CD. The third part will give examples of protocol analysis and model validations.

ABSTRACT The design of a non-volatile analog memory is presented. The specificity of this memory ... more ABSTRACT The design of a non-volatile analog memory is presented. The specificity of this memory lies in the fact that it is realized in standard AMS 0.8 μm CMOS technology. The concept is based on the model of the floating gate transistor which sees its threshold voltage modified following the amount of carriers which are on its gate. The carrier injection physics rests on cold tunneling (Fowler-Nordheim effect)

Abstract Wireless sensor networks (WSN) are now being used in a growing number and variety of sys... more Abstract Wireless sensor networks (WSN) are now being used in a growing number and variety of systems and applications. The present paper addresses the issue of wireless sensors operating in specific, possibly harsh propagation conditions in industrial ...

HAL (Le Centre pour la Communication Scientifique Directe), Jun 7, 2016

RESUME-Cet article présente les limites de la commutation douce sur la topologie Flyback active-c... more RESUME-Cet article présente les limites de la commutation douce sur la topologie Flyback active-clamp dans le cadre d'une utilisation sur une large gamme de tension d'entrée. Nous avons mis au point une stratégie de suivi de commutation en creux de tension permettant le maintien d'une commutation en creux de tension permettant un gain de 2% à 4% par rapport à une commande classique sur la moitié haute de la plage de tension d'alimentation. Cette stratégie a été testée sur un convertisseur 30 W-12 V alimenté entre 20 V et 120 V. Mots-clés-Flyback, active-clamp, creux de tension, large plage.

ABSTRACT An application specific integrated circuit (ASIC) dedicated to capacitance measurement i... more ABSTRACT An application specific integrated circuit (ASIC) dedicated to capacitance measurement is presented. After introducing the key features of capacitance meters and the necessity to obtain compatibility with most industrial transducers, and dealing with design issues related to achievement of accuracy, we present the circuit description. The designed circuit is based on a second-order switched-capacitor sigma-delta modulator and includes voltage output, frequency output and pulse width modulation (PWM) output. The capacitance to measure is part of the first integrator. Calibration and temperature compensation are integrated in the ASIC. We then present the ASIC architecture (CMOS 0.8 μm) which occupies 3.7 mm2 and give experimental results demonstrating the accuracy of the circuit. We conclude by giving the test measurements for the different parts of the circuits.

ABSTRACT The design of a CMOS current conveyors based analog multiplier/divider is presented. A t... more ABSTRACT The design of a CMOS current conveyors based analog multiplier/divider is presented. A transresistance amplifier using four current conveyors has been designed in order to achieve a 80 MHz bandwidth in a standard 0.8 μm CMOS process. Two four-MOSFET transconductors perform the multiplication and the division. Because of the low area dedicated to the current conveyor, the proposed circuit is really area-efficient for high integration

Abstract—This paper presents a new tool titled "Param2bode" for dynamic performance ana... more Abstract—This paper presents a new tool titled "Param2bode" for dynamic performance analysis of compensated three-stage amplifiers. It adjusts the parameters while observing the effects on dynamic performance in real time. Param2bode is based on equations generated ...

Abstract—This paper shows a study of the Nested Miller Compensation (NMC) and the Reversed Nested... more Abstract—This paper shows a study of the Nested Miller Compensation (NMC) and the Reversed Nested Miller Com-pensation (RNMC) schemes and their optimization for a higher operational amplifier factor of merit. Through the computation of the transfer function, a systematic ...

Abstract—This paper shows the multipath frequency compen-sation in a general purpose operational ... more Abstract—This paper shows the multipath frequency compen-sation in a general purpose operational amplifier. Firstly, it deals with the requirements of a general purpose opamp and introduces the need of the frequency compensation in the current circuits. Then, the rules to integrate ...

ABSTRACT A precision capacitance meter has been developed based on a switched-capacitor sigma del... more ABSTRACT A precision capacitance meter has been developed based on a switched-capacitor sigma delta analog-to-digital converter (ADC). It consists on a second order sigma delta architecture in which the capacitance to be measured takes part of the first integrator. A voltage reference is converted through the sigma delta ADC depending on the capacitance value. The whole operation is insensitive to stray capacitance and amplifier offset. For accurate requirements, calibration as well as temperature compensation have been integrated in the final chip

Low temperature poly-silicon thin film transistors (LTPS TFT) technology is very suitable for low... more Low temperature poly-silicon thin film transistors (LTPS TFT) technology is very suitable for low cost fingerprint sensor. In this paper, a new LTPS TFT capacitive sensor is presented. The proposed sensing scheme is based on charge sensitive amplifiers using correlated double sampling techniques (CDS) for offset voltage cancellation. Simulation results exhibit that the random offset voltage is successfully compensated.

ABSTRACT A wideband amplifier design for NMR signal application is described in this paper. The a... more ABSTRACT A wideband amplifier design for NMR signal application is described in this paper. The amplifier is based on current-conveyors and benefits from several advantages: large bandwidth, low noise, low offset and low number of discrete components needed for the implementation. In this application, current conveyor is based on the voltage to current conversion using op-amp and current mirror. The amplifier is designed to operate up to 500 MHz using a standard CMOS technology. This paper describes the structure, the principle, the simulation results and practical test of this amplifier.

ABSTRACT In this article, we present a new method to improve analog design automation and design ... more ABSTRACT In this article, we present a new method to improve analog design automation and design reuse. A top-down constraint driven methodology is applied to design complex analog system. This approach formulates the design problem as a multi objective optimization problem (MOOP). As the knowledge needed to build an optimization problem dedicated to an analog circuit is still out of reach of designers, our approach propose a new efficient way to capture design performance metrics allowing an automatic optimization problem formulation. Based only on performance specifications (e.g., gain of 80 dB) and preferences of the designers (i.e, maximize or minimize a given performance metric), a multi objective optimisation problem (MOOP) is built. An example using hybrid algorithm consisting in coupling a pattern search based algorithm and a conjugate gradient based one to solve the MOOP for a CMOS two stage opamp is given.

International Conference on Circuits, Jul 23, 2007

This paper presents a new method to improve analog design automation and thus design reuse. A top... more This paper presents a new method to improve analog design automation and thus design reuse. A topdown constraint driven methodology is applied to design complex analog system. This approach formulates the design problem as a multi objective optimization problem (MOOP). In the last decades optimization has been introduced in the field of analog design. Nevertheless, the knowledge needed to build an optimization problem dedicated to an analog circuit is still out of reach of designers. Our approach is a new efficient way to capture design performance metrics allowing an automatic optimization problem formulation. Based only on performance specifications (e.g., gain of 80dB) and preferences of the designers (i.e, maximize or minimize a given performance metric), a multi objective optimisation problem (MOOP) is built. An example using hybrid algorithm involving a pattern search based algorithm and a conjugate gradient based one to solve the MOOP for a CMOS two stage Opamp is given.

La complexite des reseaux de communications, qu'ils soient locaux ou etendus, ne peut etre mo... more La complexite des reseaux de communications, qu'ils soient locaux ou etendus, ne peut etre modelisee que partiellement par les methodes mathematiques existantes. L'analyse des performances et du comportement des reseaux etendus en fonction des techniques de routage adaptatifs est encore mal maitrisee. De meme, il peut etre utile d'etudier quantitativement les techniques d'acces aux reseaux locaux en fonction de leur configuration ou de leur utilisation. La simulation aleatoire a evenement discret est une solution qui peut prendre en compte toutes les specifications d'un reseau sans les simplifier, il existe encore peu d'outils specialises dans la simulation de reseaux. Dans une premiere partie, apres avoir evoque les roles de la modelisation et de la simulation dans les systemes notamment les systemes de communications, nous presentons les principaux criteres qu'il faut etudier afin de pouvoir faire un choix correct d'outil de modelisation et de simulation; une etude comparative des outils les plus utilises est presentees. La presentation des modeles de simulations que nous avons concu pour representer les reseaux de communications locaux et etendus fait l'objet du deuxieme chapitre. La troisieme partie sera consacree a "OSIRES",· l'outil de simulation de reseaux que nous avons developpe. Notre etude est poursuivie par l'analyse des differents algorithmes de routages deterministes ou adaptatifs rencontres dans des reseaux existants ou proposes dans la litterature. Dans une derniere partie les techniques d'acces aux reseaux locaux retenues par l'OSI sont analysees et comparees. Nous concluons ce memoire par les perspectives et les suites a donner a ce travail.

HAL (Le Centre pour la Communication Scientifique Directe), Sep 12, 2002

... PAU RAYONNEMENT IONISANTS GEMPPM* * * PHYSIQUE DE LA MATIERE PRODUCTIQUE ET INFORMATIQUE DES ... more ... PAU RAYONNEMENT IONISANTS GEMPPM* * * PHYSIQUE DE LA MATIERE PRODUCTIQUE ET INFORMATIQUE DES SYSTEMES MANUFACTU-RIERS PHYSIQUE DE LA MATIERE LAEPSI* * ** MODELISATION ... Min, emèrite) ROUBY D. ROUX JJ RUBEL P. RUMELHART ...

International Journal of Sensor Networks and Data Communications, 2016

Remote patient monitoring enables medical facilities and personnel to monitor patients outside of... more Remote patient monitoring enables medical facilities and personnel to monitor patients outside of conventional clinical settings. This technology is greatly affected by the available energy sources. The limited energy supply is the bottleneck for measurement, data transmission, network connection and lifetime. Thus, efficient power consumption estimation in the early stage of the design would give the user an insight on its feasibility within medical constraints. In this paper, a power-oriented Matlab based design tool is proposed. It will help the user to make an energy aware design. In fact, it will enable him to determine the power consumption of each node based on a set of selected components, the daily routine of the patient and many other factors. It will also allow him to test multiple configurations prior to the physical implementation. This will minimize the time and financial impact of any modification. Furthermore, it will provide guidance to properly adapt the design within the requirements of the application: Choosing components, energy sources, etc. A validation is proposed via a physical implementation in order to compare the results obtained through simulation with practical measurements. Future works aim to take into account memory access operations, include several sensors operating within a network, and adapt the tool to other applications (smart buildings, environmental monitoring, etc.).

ABSTRACT Complexity of communication networks, such as LANs or MANs, can only be partially descri... more ABSTRACT Complexity of communication networks, such as LANs or MANs, can only be partially described by the means of mathematical modeling theory. Performance and comportment analysis function of adaptative routing is not yet accurate. We propose a modelling tool based on SLAM language. After giving the links between a network structure and SLAM facilities, we give an application example for modelling and analysis of a packet switched communication network

ABSTRACT A novel circuit for an analog multiplier in a standard CMOS process is described. It is ... more ABSTRACT A novel circuit for an analog multiplier in a standard CMOS process is described. It is based on a two-current conveyors cell associated with a four MOSFET transconductor. This differential multiplier achieves a bandwidth of 80 MHz with a total harmonic distortion of two percents, because of the use of high-frequency current conveyors

Proceedings of SPIE, Feb 17, 1995

ABSTRACT Performance evaluation of access methods for Local Area Networks (LAN), can only be part... more ABSTRACT Performance evaluation of access methods for Local Area Networks (LAN), can only be partially studied by the mean of classical mathematical methods. Random simulation, based on discrete events, can take into account all the specifications without simplifying them. A study of the simulation language SLAM has demonstrated that this tool can be easily studied for this kind of problem. The first part of the paper will deal with a short description of SLAM facilities. In the second part, we will discuss of the modelling of the most common used methods for access control for LAN, token-passing and CSMA/CD. The third part will give examples of protocol analysis and model validations.

ABSTRACT The design of a non-volatile analog memory is presented. The specificity of this memory ... more ABSTRACT The design of a non-volatile analog memory is presented. The specificity of this memory lies in the fact that it is realized in standard AMS 0.8 μm CMOS technology. The concept is based on the model of the floating gate transistor which sees its threshold voltage modified following the amount of carriers which are on its gate. The carrier injection physics rests on cold tunneling (Fowler-Nordheim effect)

Abstract Wireless sensor networks (WSN) are now being used in a growing number and variety of sys... more Abstract Wireless sensor networks (WSN) are now being used in a growing number and variety of systems and applications. The present paper addresses the issue of wireless sensors operating in specific, possibly harsh propagation conditions in industrial ...

HAL (Le Centre pour la Communication Scientifique Directe), Jun 7, 2016

RESUME-Cet article présente les limites de la commutation douce sur la topologie Flyback active-c... more RESUME-Cet article présente les limites de la commutation douce sur la topologie Flyback active-clamp dans le cadre d'une utilisation sur une large gamme de tension d'entrée. Nous avons mis au point une stratégie de suivi de commutation en creux de tension permettant le maintien d'une commutation en creux de tension permettant un gain de 2% à 4% par rapport à une commande classique sur la moitié haute de la plage de tension d'alimentation. Cette stratégie a été testée sur un convertisseur 30 W-12 V alimenté entre 20 V et 120 V. Mots-clés-Flyback, active-clamp, creux de tension, large plage.

ABSTRACT An application specific integrated circuit (ASIC) dedicated to capacitance measurement i... more ABSTRACT An application specific integrated circuit (ASIC) dedicated to capacitance measurement is presented. After introducing the key features of capacitance meters and the necessity to obtain compatibility with most industrial transducers, and dealing with design issues related to achievement of accuracy, we present the circuit description. The designed circuit is based on a second-order switched-capacitor sigma-delta modulator and includes voltage output, frequency output and pulse width modulation (PWM) output. The capacitance to measure is part of the first integrator. Calibration and temperature compensation are integrated in the ASIC. We then present the ASIC architecture (CMOS 0.8 μm) which occupies 3.7 mm2 and give experimental results demonstrating the accuracy of the circuit. We conclude by giving the test measurements for the different parts of the circuits.

ABSTRACT The design of a CMOS current conveyors based analog multiplier/divider is presented. A t... more ABSTRACT The design of a CMOS current conveyors based analog multiplier/divider is presented. A transresistance amplifier using four current conveyors has been designed in order to achieve a 80 MHz bandwidth in a standard 0.8 μm CMOS process. Two four-MOSFET transconductors perform the multiplication and the division. Because of the low area dedicated to the current conveyor, the proposed circuit is really area-efficient for high integration

Abstract—This paper presents a new tool titled "Param2bode" for dynamic performance ana... more Abstract—This paper presents a new tool titled "Param2bode" for dynamic performance analysis of compensated three-stage amplifiers. It adjusts the parameters while observing the effects on dynamic performance in real time. Param2bode is based on equations generated ...

Abstract—This paper shows a study of the Nested Miller Compensation (NMC) and the Reversed Nested... more Abstract—This paper shows a study of the Nested Miller Compensation (NMC) and the Reversed Nested Miller Com-pensation (RNMC) schemes and their optimization for a higher operational amplifier factor of merit. Through the computation of the transfer function, a systematic ...

Abstract—This paper shows the multipath frequency compen-sation in a general purpose operational ... more Abstract—This paper shows the multipath frequency compen-sation in a general purpose operational amplifier. Firstly, it deals with the requirements of a general purpose opamp and introduces the need of the frequency compensation in the current circuits. Then, the rules to integrate ...

ABSTRACT A precision capacitance meter has been developed based on a switched-capacitor sigma del... more ABSTRACT A precision capacitance meter has been developed based on a switched-capacitor sigma delta analog-to-digital converter (ADC). It consists on a second order sigma delta architecture in which the capacitance to be measured takes part of the first integrator. A voltage reference is converted through the sigma delta ADC depending on the capacitance value. The whole operation is insensitive to stray capacitance and amplifier offset. For accurate requirements, calibration as well as temperature compensation have been integrated in the final chip

Low temperature poly-silicon thin film transistors (LTPS TFT) technology is very suitable for low... more Low temperature poly-silicon thin film transistors (LTPS TFT) technology is very suitable for low cost fingerprint sensor. In this paper, a new LTPS TFT capacitive sensor is presented. The proposed sensing scheme is based on charge sensitive amplifiers using correlated double sampling techniques (CDS) for offset voltage cancellation. Simulation results exhibit that the random offset voltage is successfully compensated.

ABSTRACT A wideband amplifier design for NMR signal application is described in this paper. The a... more ABSTRACT A wideband amplifier design for NMR signal application is described in this paper. The amplifier is based on current-conveyors and benefits from several advantages: large bandwidth, low noise, low offset and low number of discrete components needed for the implementation. In this application, current conveyor is based on the voltage to current conversion using op-amp and current mirror. The amplifier is designed to operate up to 500 MHz using a standard CMOS technology. This paper describes the structure, the principle, the simulation results and practical test of this amplifier.

ABSTRACT In this article, we present a new method to improve analog design automation and design ... more ABSTRACT In this article, we present a new method to improve analog design automation and design reuse. A top-down constraint driven methodology is applied to design complex analog system. This approach formulates the design problem as a multi objective optimization problem (MOOP). As the knowledge needed to build an optimization problem dedicated to an analog circuit is still out of reach of designers, our approach propose a new efficient way to capture design performance metrics allowing an automatic optimization problem formulation. Based only on performance specifications (e.g., gain of 80 dB) and preferences of the designers (i.e, maximize or minimize a given performance metric), a multi objective optimisation problem (MOOP) is built. An example using hybrid algorithm consisting in coupling a pattern search based algorithm and a conjugate gradient based one to solve the MOOP for a CMOS two stage opamp is given.

International Conference on Circuits, Jul 23, 2007

This paper presents a new method to improve analog design automation and thus design reuse. A top... more This paper presents a new method to improve analog design automation and thus design reuse. A topdown constraint driven methodology is applied to design complex analog system. This approach formulates the design problem as a multi objective optimization problem (MOOP). In the last decades optimization has been introduced in the field of analog design. Nevertheless, the knowledge needed to build an optimization problem dedicated to an analog circuit is still out of reach of designers. Our approach is a new efficient way to capture design performance metrics allowing an automatic optimization problem formulation. Based only on performance specifications (e.g., gain of 80dB) and preferences of the designers (i.e, maximize or minimize a given performance metric), a multi objective optimisation problem (MOOP) is built. An example using hybrid algorithm involving a pattern search based algorithm and a conjugate gradient based one to solve the MOOP for a CMOS two stage Opamp is given.