Adel Ghazel | SupCom - Academia.edu (original) (raw)

Papers by Adel Ghazel

International Conference on Recent Advances in Space Technologies, 2003. RAST '03. Proceedings of

ABSTRACT

2017 IEEE International Symposium on Power Line Communications and its Applications (ISPLC)

This paper focuses on the characterization and modelling of impulse noise in narrowband power lin... more This paper focuses on the characterization and modelling of impulse noise in narrowband power line communication. Two modelling approaches of the measured noise are studied and compared: the memoryless Middleton class-A model and the Markov-Middleton model with memory. Model comparisons with measurements show that Markov-Middleton is compliant with the impulse noise temporal structure since it considers the pulse sample correlation. In the frequency domain, both models do not well represent the frequency behaviour of the impulse noise. Differences in duration and distribution in time of errors generated by measured/modelled noise are noticed.

In this paper, a comparative study is proposed for two modeling approaches of the random impulse ... more In this paper, a comparative study is proposed for two modeling approaches of the random impulse noise measured in narrowband power lines. This study concerns the memoryless Middleton Class A model and the Markov-Middleton model with memory. Models comparison with measurements is performed and it is shown that Markov-Middleton one is compliant to the impulse noise temporal structure since it considers the pulses samples correlation. However, the comparison in the frequency domain shows that both models do not well represent the frequency behavior of the impulse noise. Index Terms impulse noise, Middleton class A model, Markov chains, narrowband plc, stochastic model.

The purpose of this paper is to compare two estimation methods when identifying the coefficients ... more The purpose of this paper is to compare two estimation methods when identifying the coefficients of the Simplified Volterra Series (SVS) model, in order to linearize a class AB GaN Power Amplifier (PA) driven by a 20-MHz LTE-A signal. First, a Digital Predistorter (DPD) design using the cholesky decomposition based inversion method and the Least Square QR (LSQR) algorithm is carried out, and next the performances of each method are analyzed in terms of computational complexity and suppressing distortions capability. The co-simulation test results show that the LSQR performs better than Cholesky decomposition in terms of Adjacent Channel Power Ratio (ACPR) and Normalized Mean Square Error (NMSE) by a margin of 3 dB and 4 dB, receptively.

While GPS high quality products supplied by leading global components (Motorola, Analog Devices, ... more While GPS high quality products supplied by leading global components (Motorola, Analog Devices, Sirf, Maxim, Qualcomm ...) are available, many research works are carried out in order to improve sensitivity, response time, dynamics, accuracy, size and power consumption. In addition, continuity of the positioning service between outdoor and indoor appears as a must for the next years. Most of the receivers are limited to a single standard and do not offer positioning services in areas where satellites are not available. Although many techniques have been proposed these last ten years, ranging from High-Sensitivity GNSS (Global Navigation Satellite System) to sensor networks, through Assisted-GNSS or WLAN based approaches, no ultimate solution seems yet to provide the answer to the indoor positioning problem, probably crucial to Location Based Services. In order to enhance receiver performance in harsh environments where significant multipath problems are present and ensure continuity...

Un generateur materiel de bruit blanc gaussien de bonne qualite est developpe sur une cible FPGA,... more Un generateur materiel de bruit blanc gaussien de bonne qualite est developpe sur une cible FPGA, dans le cadre d'une emulation de canal de communications mobiles. Une grande precision et un faible cout materiel du generateur sont obtenus par l'utilisation conjointe de la methode de Box-Muller et du theoreme de la limite centrale. Un modele parametrable ecrit avec MATLAB, du generateur de bruit gaussien est presente. Les resultats en complexite et performance obtenus grâce aux modeles MATLAB et VHDL montrent l'interet du modele propose.

2017 IEEE International Symposium on Power Line Communications and its Applications (ISPLC), 2017

Introduction Battery stacks based on lithium-ion (Li-ion) cells are used in many applications suc... more Introduction Battery stacks based on lithium-ion (Li-ion) cells are used in many applications such as hybrid electric vehicles (HEV), electric vehicles (EV), storage of renewable energy for use at a later time, and energy storage on the grid for various purposes such as grid stability, peak shaving, and renewable energy time shifting. In these applications, it is important to measure the state of charge (SOC) of the cells, which is defined as the available capacity (in Ah) and expressed as a percentage of its rated capacity. The SOC parameter can be viewed as a thermodynamic quantity enabling one to assess the potential energy of a battery. It is also important to estimate the state of health (SOH) of a battery, which represents a measure of the battery’s ability to store and deliver electrical energy, compared with a new battery. Analog Devices power control processor, the ADSP-CM419, is a perfect example of a processor that has the capability to deal with battery charging techniqu...

In this paper, two decision methods for the conventional and spread frequency shift keying (FSK a... more In this paper, two decision methods for the conventional and spread frequency shift keying (FSK and SFSK) are detailed and their extension to the coded FSK using the permutation coding are proposed. The performance results of the different methods are compared under the real indoor narrowband PLC (NB PLC) channel attenuation and impulse noise. The decision schemes are mainly the probability density function PDF-based system for the SFSK and the Non-PDF-based system (select largest) for the conventional FSK. The BER performances of the different techniques prove that the coded FSK using the Select Largest method achieves good performance results in the PLC constraints while having a low complexity, in comparison with SFSK system. The coded FSK Select Largest gives an error floor equal to 6×10 under impulse noise and channel effect compared to 2×10achieved by the coded SFSK. Index Terms FSK, SFSK, coded modulation, permutation codes, channel attenuation, impulse noise, BER.

This work presents a low-power multistandard decimation and channel selection filter architecture... more This work presents a low-power multistandard decimation and channel selection filter architecture. The filter is suitable after an over-sampling sigma-delta converter and performs decimation in two stages. The first stage is a modified structure of the Cascade of Integrators-Combs (CIC) filter and allows reducing sampling rate downto only the double of the Nyquist frequency. The second stage composed of classical FIR filter, has relaxed specifications and performs channel selection. Implementation of the proposed filter for UMTS and GSM standards shows good filtering performances. The signal to ratio measured for UMTS is 14,65 dB and for GSM 26,96 dB which satisfy largely the standards requirements. Implementation on ASIC 65-nm process technology shows power consumption gain of 14% in comparison to previously proposed low-power architecture.

Concurrency and Computation: Practice and Experience, 2021

This paper proposes a coded modulation scheme based on frequency shift keying (FSK) modulation an... more This paper proposes a coded modulation scheme based on frequency shift keying (FSK) modulation and a simple binary permutation code. FSK detection is based on the knowledge of the probability density function (PDF) of the noise and the attenuation of the channel, called FSK “Soft‐Decision” (FSK/SD) detection. We introduce an approximation of the FSK/SD, called FSK “Select Largest” (FSK/SL). We compare the FSK/SL detection with the classical PDF‐based detection techniques, such as FSK/SD and spread‐FSK (SFSK), for both coded and uncoded transmission. As a practical application, we use the power line communication (PLC) channel. We analyze and compare the performances for a narrowband PLC channel with attenuation and impulse noise.

Abstrac tContinuous-Time delta sigma modulators (CT ∆ΣM), by their nature, are mixed-signal syste... more Abstrac tContinuous-Time delta sigma modulators (CT ∆ΣM), by their nature, are mixed-signal systems. That fact creates a discontinuity in the traditional IC design flow which assumes that “discrete” and “continuous” time domain designs require separate design tools. In this work, we present a top level behavioral approach of modeling CT complex Bandpass (CBP) ∆ΣM using VHDL-AMS language. The CT ∆Σ model can be used within the analog IC design environment. Fifth-order CT CBP ∆ΣM which is tailor made for Bluetooth and WiFi Low-IF receiver demonstrates clearly the modeling technique.

1999 IEEE Africon. 5th Africon Conference in Africa (Cat. No.99CH36342)

ABSTRACT This work deals with software radio. It presents an implementation of a GMSK transmitter... more ABSTRACT This work deals with software radio. It presents an implementation of a GMSK transmitter and receiver algorithms for the GSM system on a fixed-point 16 bit-33MIPS Analog Devices DSP. By an optimal software design that takes the maximum advantages from DSP architecture facilities, good real time experimental performances have been obtained for the GMSK modem implemented modules

Concurrency and Computation: Practice and Experience

In this article, we propose a new criterion for a switching algorithm to be used in MIMO‐OFDM sys... more In this article, we propose a new criterion for a switching algorithm to be used in MIMO‐OFDM systems. The switching algorithm, which selects between spatial multiplexing and MIMO diversity using the Demmel condition number as selection metrics, is first analyzed. Then, we show the limitation of this criterion, when increasing the receive antenna number. As a solution, we propose multiantenna processing and SNR switching criterion as a novel selection metric. The channel between the transmitter and the receiver is assumed a Rayleigh‐fading channel. Simulations results show that the proposed switching algorithm improves the performances in terms of bit error rate (BER) for symmetric and asymmetric MIMO systems. The gain is about 3 dB at BER = 10−4 in (4×4) architecture and 2 dB at BER = 10−4 in (3×2) architecture.

2016 11th International Design & Test Symposium (IDT), 2016

The nonlinearity is an important factor that limit the improvement of the overall performance of ... more The nonlinearity is an important factor that limit the improvement of the overall performance of a GNSS receiver. In order to prove the subsampling GNSS receiver performance for a weak desired system, a simple method is to characterize the derivation in nonlinearity and to quantify the impact on the wanted signal.

2016 8th International Conference on Games and Virtual Worlds for Serious Applications (VS-GAMES), 2016

Falls are a serious problem among older adults. Many research studies have reported that risk fal... more Falls are a serious problem among older adults. Many research studies have reported that risk falls can be minimized with exercising and physical activity. This paper proposes two prototype games that include tasks for balance and postural control for elderly people. It can be integrated in rehabilitation programs in both clinics and home settings. The physiotherapist has preliminarly validated the proposed games and a clinical trial to determine their effectiveness is planned as a further work.