M. KHALFA Ali

MCA

Directory of teachers

Department

Departement of ELECTRONICS

Research Interests

Specialized in Departement of ELECTRONICS. Focused on academic and scientific development.

Contact Info

University of M'Sila, Algeria

Email : ali.khalfa@univ-msila.dz

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Recent Publications

2024-12-17

Analysis and Design of Wideband Vivaldi Antenna for 5G Applications

This paper presents a design and simulation of a novel wideband Vivaldi antenna, which is obtained using exponential curves to achieve optimal performance across multiple frequencies. The proposed antenna operates at four frequency bands 1.14 GHz, 2.84 GHz, 3.5 GHz, and 5 GHz, which makes it suitable for a wide range of 5G applications. The tapered slot Vivaldi antenna, with compact dimensions of 49 × 48.4 × 1.6 mm3, integrates a 3 mm microstrip feed and is designed on an FR4 substrate, which has a dielectric constant of 4.4 with a tangent loss of 0.02. To enhance operational efficiency of our Vivaldi antenna, a circular cut has been introduced in the ground plane, which improving significantly the antenna's radiation characteristics and impedance matching. The design was carried out and analyzed using CST studio simulator. The simulation results indicate a significant improvement in the performance across various stages of the design process. This iterative design process underscores the adaptability of the antenna for a wide frequency band, including 5G bands. Due to its compact size, wideband capabilities, and improved gain and directivity, our proposed enhanced Vivaldi antenna demonstrates considerable promise for integration into modern communication systems, particularly in 5G applications, where wide bandwidth and multi-frequency operations are very important.
Citation

M. KHALFA Ali, (2024-12-17), "Analysis and Design of Wideband Vivaldi Antenna for 5G Applications", [international] 1st International Conference on Electrical, Computer, Telecommunication and Energy Technologies (ECTE-Tech) , Oum El Bouaghi, Algeria

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2024-09-18

Performance analysis of mean level CFAR detectors in homogeneous gamma-distributed radar clutter

In this paper, a novel and exact mathematical formulation of three mean level constant false alarm rate (CFAR) detectors has been developed considering a homogeneous gamma-distributed (GM) clutter. These detectors include the cell averaging (CA), the greatest-of (GO), and the smallest-of (SO)-CFAR detection schemes. To do so, we derived closed-form expressions for the probability density function (pdf), and the cumulative distribution function (cdf) of the sum of an exponential fluctuating target submerged in gamma-distributed sea clutter. Then, we developed exact and explicit expressions for the probability of false alarm (Pfa) and probability of detection (Pd) of the optimal fixed threshold detector and the three considered CFAR detectors. The correctness of our expressions is then examined and validated via numerical simulations. Assuming a homogeneous GM background, the detection performance of these three detectors is carried out, discussed, and compared with that of the optimal detector. Experimental results with Sentinel-1 synthetic aperture radar (SAR) data demonstrate the effectiveness of the proposed closed-form expressions and show that the considered CFAR schemes are efficient for ship detection in sea clutter backgrounds.
Citation

M. KHALFA Ali, (2024-09-18), "Performance analysis of mean level CFAR detectors in homogeneous gamma-distributed radar clutter", [national] International Journal of Remote Sensing , Taylor & Francis

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2024-05-30

Design of a Reconfigurable Antenna for WLAN Applications

in this paper presents recent advancements in the design and implementation of reconfigurable antennas, focusing on their potential to enhance performance metrics such as bandwidth, gain, and radiation pattern agility. Reconfigurable antennas offer attractive potential solutions to solve the problem of the need to use multiple antennas for different applications, such as Bluetooth, Wi-Fi, WiMAX, WLAN, etc. In this paper, a novel frequency reconfigurable, the antenna design using p-i-n diode is proposed. The antenna switches at two different frequencies between 2.4 GHz and 5.2GHz. The design includes a PIN diode in the feeder to achieve frequency reconfiguration. The antenna (41×44×1.6 mm3) is designed on FR4 substrate with permittivity of 4.4 and tangential loss of 0.02 using the CST Microwave studio simulator. The resulting antenna is suitable for applications wireless local-area network (WLAN) technologies.
Citation

M. KHALFA Ali, (2024-05-30), "Design of a Reconfigurable Antenna for WLAN Applications", [international] the International Conference on Applied Sciences (ICAS - 2024) , Bosnia and Herzegovina

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2024-05-16

A novel Frequency Reconfigurable L-shaped Antenna for WiMAX and 5G Application

Reconfigurable antennas can be used in contemporary wireless and portable devices to work across many frequency bands and scan radiation patterns in accordance with user requirements. In this paper, we present a simple frequency reconfigurable antenna. Using frequency reconfigurability, one antenna can be used for many applications only by switching between the selected bands. To do the reconfigurability, PIN diodes will be used, by strategically placing these diodes within the antenna structure, the resonance frequency can be adjusted with minimal power consumption. The proposed antenna consists of two asymmetric L-shaped rectangular patches electrically connected by a single PIN diode. The suggested antenna can function in two different frequency bands, depending on the PIN diode's switching state. It operates at 2.1GHz (3G) and 3.5 GHz (5G) during forward bias of the diode, 5.3 GHz (WiMAX) and 2.1 GHz (3G) during reverse bias of the diode. The antenna (32×44×1.6 mm3) is designed on FR4 substrate with permittivity of 4.4 and tangential loss of 0.02 using the CST Microwave studio simulator. this antenna presents a high gain and favorable radiation characteristics in the operating range which is required for fifth-generation networks (5G), and microwave connectivity worldwide interoperability (WiMAX) applications.
Citation

M. KHALFA Ali, (2024-05-16), "A novel Frequency Reconfigurable L-shaped Antenna for WiMAX and 5G Application", [international] 3rd International Conference on Engineering, Natural and Social Sciences ICENSOS 2024 , Konya, Turkey

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2023-08-07

Performance Analysis of the MLG-CFAR Detector in Homogenous Gamma-Distributed Sea Clutter

This letter presents an analytical study of the performance of the maximum-likelihood gamma constant false alarm rate (MLG-CFAR) detector operating over a homogenous gamma-distributed (GM) clutter. To accomplish this task, a novel closed-form expression for the probability of false alarm and a highly accurate approximation for the probability of detection are derived. Specifically, this proposed approximation is also given in a closed form. These expressions, which can be of great interest to the radar community, are given in terms of the Gauss hypergeometric function and the Tricomi function. Besides, the proposed expressions can be easily implemented and computed using most popular scientific software packages such as MATLAB, Maple, and Mathematica. Our propositions are then tested and validated using numerical computing and Monte Carlo simulations. The obtained results demonstrate a high accuracy and significant computational advantages of the proposed expressions compared to the alternative ones. Moreover, the detection performance of the MLG-CFAR detector is also conducted assuming a homogenous clutter with a known shape parameter.
Citation

M. KHALFA Ali, fdjahli@yahoo.fr, , (2023-08-07), "Performance Analysis of the MLG-CFAR Detector in Homogenous Gamma-Distributed Sea Clutter", [national] IEEE Geoscience and Remote Sensing Letters , IEEE

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2023-08-01

Exact Closed-Form Pfa Expressions for CA- and GO-CFAR Detectors in Gamma-Distributed Radar Clutter

In this correspondence, two exact closed-form expressions for the probability of false alarm have been derived assuming a homogeneous Gamma distributed clutter. These expressions concern both the cell averaging CFAR (CA-CFAR) and the greatest of CFAR (GO-CFAR) detectors. As it will be shown, the proposed expressions are given in terms of the Gauss hypergeometric function and the second Appell function. Our expressions are then examined and validated numerically, by comparing them to their counterparts computed using numerical integrals and Monte-Carlo simulations, considering various scenarios.
Citation

M. KHALFA Ali, Farid Djahli, , (2023-08-01), "Exact Closed-Form Pfa Expressions for CA- and GO-CFAR Detectors in Gamma-Distributed Radar Clutter", [national] IEEE Transactions on Aerospace and Electronic Systems , IEEE

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2022

Blind Image Separation Using the JADE Method

Blind source separation (BSS) concerns the signal processing techniques that aim to find several elementary components of sources from linear combinations of these sources received on several sensors. This paper presents a method for the extraction of these independent components. It is called Joint Approximate Diagonalization of Eigenmatrices (JADE) and uses fourth-order cumulants. A simulation example shows the performance of the proposed algorithm by displaying its high separation accuracy. The proposed technique is compared to the Equivariant Adaptive Source Separation Algorithm (EASI).
Citation

M. KHALFA Ali, Amardjia Noureddine, , (2022), "Blind Image Separation Using the JADE Method", [national] engproc , MDPI Tongzhou Office, Beijing

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A Novel Blind Image Source Separation Using Hybrid Firefly Particle Swarm Optimization Algorithm

Signal and image separation are extensively used in numerous imaging applications and communication systems. In this paper, a novel Blind Source Separation (BSS) approach, based on the Hybrid Firefly Particle Swarm Optimization (HFPSO), is proposed for separating mixed images. This approach processes the observed source without any prior knowledge about the model and the statistics of the source signal. The proposed method presents high robustness against local minima and converges quickly to the global minimum. Via numerical simulations, the proposed approach is tested and validated in comparison with standard Particle Swarm Optimization (PSO), Robust Independent Component Analysis (RobustICA), and Artificial Bee Colony (ABC) algorithms. The obtained results show that the presented technique outperforms the existing ones in terms of quality of image separation, the Signal-to-Noise Ratio (PSNR), and Structural Similarity Index Measure (SSIM). Moreover, the obtained results demonstrate that our approach provides also promising results in image separation from noisy mixtures.
Citation

M. KHALFA Ali, Farid Djahli, , (2022), "A Novel Blind Image Source Separation Using Hybrid Firefly Particle Swarm Optimization Algorithm", [national] Engineering, Technology & Applied Science Research , ETASR

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2021

Blind Image Separation Using Joint Approximate Diagonalization of Eigenmatrices (JADE) Method

Blind source separation (BSS) concerns the signal processing techniques that aim to find several elementary components of sources from linear combinations of these sources received on several sensors. This paper presents a method for the extraction of these independent components. It is called Joint Approximate Diagonalization of Eigenmatrices (JADE) and uses fourth-order cumulants. A simulation example shows the performance of the proposed algorithm by displaying its high separation accuracy. The proposed technique is compared to the Equivariant Adaptive Source Separation Algorithm (EASI)
Citation

M. KHALFA Ali, Amardjia Noureddine, , (2021), "Blind Image Separation Using Joint Approximate Diagonalization of Eigenmatrices (JADE) Method", [national] ICCEIS2021 , University of Boumerdes

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2019

Blind Audio Source Separation Based On High Exploration Particle Swarm Optimization

Blind Source Separation (BSS) is a technique used to separate supposed independent sources of signals from a given set of observations. In this paper, the High Exploration Particle Swarm Optimization (HEPSO) algorithm, which is an enhancement of the Particle Swarm Optimization (PSO) algorithm, has been used to separate a set of source signals. Compared to PSO algorithm, HEPSO algorithm depends on two additional operators. The first operator is based on the multi-crossover mechanism of the genetic algorithm while the second one relies on the bee colony mechanism. Both operators have been employed to update the velocity and the position of the particles respectively. Thus, they are used to find the optimal separating matrix. The proposed method enhances the overall efficiency of the standard PSO in terms of good exploration and performance. Based on many tests realized on speech and music signals supplied by the BSS demo, experimental results confirm the robustness and the accuracy of the introduced BSS technique.
Citation

M. KHALFA Ali, Nourredine AMARDJIA, Djamel chikouche, Abdelouahab Attia, , (2019), "Blind Audio Source Separation Based On High Exploration Particle Swarm Optimization", [national] KSII Transactions on Internet and Information Systems , TIIS

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2016-10-24

Analysis Study of Radar Probability of Detection for Fluctuating and Non-fluctuating Targets

This paper presents a solution to enhance the Global Navigation Satellite System (GNSS) positioning by mitigating the multipath (MP) influence. In several cases GNSS navigation such as Global Positioning System (GPS) and Future Galileo needs a very high accuracy in positioning. As MP is a major source of inaccuracy, we propose to use the concept of Binary-Asymmetric Phase-Only Correlation (BA–POC) in the GNSS receivers in order to estimate LOS delay of received signal. BAPOC was applied to the area of ranging to help identifying the line of sight (LOS) in MP-abundant environments, Using the aforementioned scheme, the MP induced bias can be efficiently reduced. The obtained results show that the proposed scheme gives better performance over existing correlation-based schemes. Thus, it results in a high accuracy in GNSS positioning.
Citation

M. KHALFA Ali, (2016-10-24), "Analysis Study of Radar Probability of Detection for Fluctuating and Non-fluctuating Targets", [national] International Conference on Technological Advances in Electrical Engineering Skikda, Algeria, 24-26 October 2016 , Skikda, Algeria,

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2009-03-22

Application of the BA-POC scheme for multipath mitigation in GPS/Galileo receivers

This paper presents a solution to enhance the Global Navigation Satellite System (GNSS) positioning by mitigating the multipath (MP) influence. In several cases GNSS navigation such as Global Positioning System (GPS) and Future Galileo needs a very high accuracy in positioning. As MP is a major source of inaccuracy, we propose to use the concept of Binary-Asymmetric Phase-Only Correlation (BA–POC) in the GNSS receivers in order to estimate LOS delay of received signal. BAPOC was applied to the area of ranging to help identifying the line of sight (LOS) in MP-abundant environments, Using the aforementioned scheme, the MP induced bias can be efficiently reduced. The obtained results show that the proposed scheme gives better performance over existing correlation-based schemes. Thus, it results in a high accuracy in GNSS positioning.
Citation

M. KHALFA Ali, (2009-03-22), "Application of the BA-POC scheme for multipath mitigation in GPS/Galileo receivers", [international] 5 th International Conference: Sciences of Electronic, Technologies of Information and Telecommunications March 22-26, 2009 – Tunisia , Tunisia

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