Telecommunication
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Item mplementation of low band booster on LTE 900MHz network for enhanced edge user experience(Université M’hamed Bougara de Boumerdes : Institut de Genie Electrique et Electronique, 2024) Bouloum, Sofiane; Boursas, Idir; Smailii, Nesrine ( Supervisor)Mobile telephone operators, in functions of the network load, are always looking for innovative solutions in order to improve the quality of service(QoS) given the non-availability or the limitation of the band spectral bandwidth. On the EGSM band, Djezzy has decided to activate 4G (L900) on 3 MHz as bandwidth. Given the spectral limitation of the band, the Qos is more than essential in order to offer the best 4G experience to our clients. The objective of our thesis is to improve the performance of the 4G network (L900 3MHz) in terms of throughput and make the best use of these spectral resources limited by the deployment and optimization of the “Low band booster” solution. This will be done by firs tstudyin gth earchitectur eo f a4 GLT Enetwork ,th edifferen tQo sparameter sa swell as reviewing the strategy adopted in implementation of carrier aggregation, mid and low band coordination and scheduling of data transmission. The contribution of our work in this project is to optimise the overall Djezzy radio access network to meet the high demand of a good quality service particularly the high demand for network capacity.Item Microgrids resiliency using multi-agent system communication technology(Université M’hamed Bougara de Boumerdes : Institut de Genie Electrique et Electronique, 2024) Attou, Lina; Belaidi, Hadjira (Superviseur)Nowadays, communication and data exchange are key factors for the resilience improvement of a microgrid (MG) against natural disasters and play a pivotal role in the energy management (EM) fields .Hence ,the main objective of this project is to improve MGresilience and control its energy management system (EMS) using a multi-agent system (MAS) communication approach. First, the proposed work optimizes the load power consumption inside one MG based on the available power resources; then, the strategy is expanded to optimize power usage to improve resilience when dealing with many MG systems. The simulation of the multi-microgrid (MMG) system is done using both MATLAB Simulink and Cisco packet tracers. Various scenarios are simulated to evaluate the performance of the MAS in maintaining flexibility, stability, an dresiliency. The Cisco packet traceris used to model the communication network to ensure a robust and secure data exchange between agents. The results demonstrate that the integration of MAS communication technology significantly improves MGs’ power management.Item Adaptive co-existence of OFDM and OTFS for Multi-Mobility scenarios in wireless communications(Université M’Hamed Bougara de Boumerdes : Institut de génie electrique et electronique (IGEE), 2024) Zegrar, Hadj Mebarek; Smaili, Nesrine (Supervisor)The rapid evolution of technology necessitates the development of new waveforms capable of handling the increasing demands of high-mobility scenarios. Orthogonal Frequency Di-vision Multiplexing (OFDM), although extensively used in current wireless communication systems, experiences significant performance degradation in highmobility environments due to large Doppler shifts and Doppler spread effects .To address these challenges, a novel waveform called Orthogonal Time Frequency Space (OTFS) has been developed, offer ingsuperior performance in highmobility scenarios by exploiting delay-Doppler diversity. However, OTFS introduces high processing complexity and does not exhibit obvious performance advantages for low-mobility users, where OFDM remains efficient and effective. There fore, there is a critical need to develop a co-existence method that leverages the strengths of both waveforms. we proposed a method to check the user’s velocity and dynamically switch between OFDM and OTFS based on user mobility. By doing so, the communication system can achieve optimal performance of Bit Error Rate (BER) versus Signal-to-Noise Ratio (SNR), maintaining robust and efficient data transmission across diverse mobility conditions.Item Design of compact Dual-Band fractal antennas for WLAN/WiMAX applications(Université M’Hamed Bougara de Boumerdes : Institut de génie electrique et electronique (IGEE), 2024) Drouiche, Hanane; Djafri, Kahina (Supervisor)In this project, a new design approach is presented for achieving a miniaturized dual-band microstrip patch antenna (MPA) suitable to be used for 2.4 GHz WLAN band, and 5.5 GHz WiMAX band. The first proposed antenna which is composed of a semi-circular radiating arm attached to four identical smaller semicircular arms to form a comb structure loaded with a horizontal rectangular stub with a 50- O transmission by feed line printed on the top side of an FR4 substrate. A tapered partial ground plane is printed on the back side of the substrate. The second proposed design is composed of three interconnected??- shaped arms feed with a 50 Ohm microstrip line on the top side of the FR-4 substrate and a tapered ground plane in its back side. A CST Microwave Studio (CST MWS) is used to model the designed antennas, and simulation results, in terms of reflection coefficient (S11), realized peak gain, efficiency and radiation patterns. To validate the design concept, the antenna designs are fabricated, the simulated and measured S11 results are nearly coincide with each other. The semi-circular comb antenna is characterized by miniaturized size of 24 × 29.5 ???? 2, and measured bandwidths of 600 MHz (2–2.6 GHz) and 2.6 GHz (5.4–8 GHz). The second proposed structure, triple ??- shaped patch, is characterized by compact size of 22 × 32 ???? 2, and measured bandwidths of 800 MHz (2–2.8GHz) and band 2.4 GHz (4-6.4 GHz ).Item A compact MIMO UWB antenna with band notched characteristicsat WLAN frequency band(Université M’Hamed Bougara de Boumerdes : Institut de génie electrique et electronique (IGEE), 2024) Adjeroud, Nadjet; Mouhouche, Faïza (Supervisor)This work presents a compact UWB MIMO antenna with band notch characteristics for WLAN application is designed and investigated. The proposed MIMO antenna consists of two unit cell antennas, being comprised of a Microstrip feed line and a partial ground plane, and these radiators are placed parallel to each other. A single antenna comprises an inverted Christmas tree shaped patch fed by a 50 OMicrostrip line and partial ground plane is designed for achieving UWB application. The operating frequency of the proposed single antenna is 3.5–14.5 GHz with a return loss of less than -10 dB. Subsequently, a circular split ring shaped slot is implemented in the radiating element to optimize the antenna for WLAN band rejection at 5.6-6.2GHz. Furthermore, a 2 × 1 MIMO antenna is designed by utilizing the polarization diversity technique. The two radiating elements are placed parallel and decoupling structure is placed between them to improve the isolation performance. Finally, the compact UWB MIMO antenna prototype is designed on the FR4 substrate with the overall dimensions of 20 × 39 × 1.63 mm3.The proposed UWB MIMO antenna design provides an impedance bandwidth (S11 less then -10 dB) of 130% (3.3–16 GHz) with band notch centered at 5.8GHz. The isolation of the proposed MIMO antenna is higher than -17?dB,. Results show that the proposed MIMO antenna is a good candidate for handheld devices for wireless personal-area networks application.Item Contribution to the design of electromagnetic power harvesting system(Université M’Hamed Bougara de Boumerdes : Institut de génie electrique et electronique (IGEE), 2024) Abed, Abdesselem; Barkat, Menouar; Azrar, Arab (Supervisor)In this report, a compact Rectenna is designed and fabricated with the aim of harvesting RF energy at the frequency of 2.4 GHz. The system consists of a 40mm x 40mm microstrip patch antenna, a Villard voltage doubler for the rectifier circuit designed with HSMS-2850 Schottkey diode for RF application. The rectifier and antenna are joined with a ?-matching network composed of printed lumped components for impedance matching, consisting of a series interdigital capacitor and shunt strip inductors. It should be mentioned that the use of printed lumped components is not found in any literature related to energy harvesting as of the writing of this report. The system has been designed on an FR-4 substrate with thickness of 1.5 mm, a tangent loss of 0.02 and relative permittivity of 4.4. Using an RF generator connected to the energy harvesting circuit, the circuit generates measurable voltage starting from 7dBm input power. The realized circuit gives a DC output voltage of 5.4mV at 20dBm input power with a PCE of 2.916 × 10 -6 %.Item A compact quad element MIMO-UWB antenna with band notch characteristics and high isolation(Université M’hamed Bougara de Boumerdes : Institut de Genie Electrique et Electronique, 2024) Chairi, Anis; Mouhouche, Faïza ( Supervisor)This work presents a compact MIMO UWB antenna with WiMAX band-notch characteristics designed and inves- tigated. The proposed MIMO antenna comprises four unit cell antennas, each consisting of a microstrip feed line and a partial ground plane, with the radiators placed perpendicular to each other. A single antenna features a trapezoid- semicircle hybrid patch fed by a 50 O microstrip line, along with a partial ground plane, is initially designed for UWB applications, operating within 3.18–18.63 GHz. An inverted T-shaped stub is subsequently implemented to optimize the antenna for WiMAX band rejection at 3.3–3.8 GHz. Furthermore, a 2 × 2 MIMO antenna is designed utilizing the polarization diversity technique. The two radiating elements are placed orthogonally, with a decoupling structure positioned between them to improve isolation performance. Finally, the compact four-port MIMO antenna prototype is constructed on the FR4 substrate, with overall dimensions of 42 × 42 × 1.63 mm³. The proposed four-port MIMO antenna design offer s abandwidt ho f2.94–2 0GHz. The antenna’s isolation is <-1 8dB, and it maintains relatively stable radiation characteristics and gain, along with a lower envelope correlation coefficie nt(E C C<0.0055).Item Design of a two-port MIMO antenna with low-mutual coupling based on a Pentagonal-Fractal ring element(Université M’hamed Bougara de Boumerdes : Institut de Genie Electrique et Electronique, 2024) Mokrani, Mohamed Amine; Djafri, K. (Supervisor)In this work, a two-element multiple-input–multiple-output (MIMO) 3.5GHz antenna covering the 3.5 WiMAX commercially useful application is proposed and analyzed. The antenna element is based on first-orde rpentagona lfracta lrin gmonopol eantenn afe db ya Y-shaped transmission line. To achieve a compact size, the sides on the pentagonal ring are loaded with a triangular shaped branches oriented towards the antenna center to obtain the fractal ring radiating element. The resulted antenna element, overall dimensions of 15x19mm2 , is fabricated and its reflectio ncoeffici en tismeasu red forexperimen talval-idation. The resulted antenna element is then used to design a two-port MIMO antenna. The MIMO antenna consists of two identical antenna elements arranged orthogonally in polarization diversity configuration. By loading the antenna with arectangular stub, the mutual coupling between the antenna elements is significantl yreduced .Th estu bi sprinted diagonally in the back side of the substrate. The resulted MIMO antenna has an overall size of 31.35x31.35mm2 with better isolation less then -19 dB. The simulated maximum realized gain and maximum radiation efficien cya re1.76dBi and 66.33% respectively. Moreover, the performance of the proposed MIMO antenna in terms of isolation, realized gain, radiation efficien cya ndradiati onpatter nsa restudied.Item Contribution to the design and analysis of microstrip antennas for smart grid applications(Université M’hamed Bougara de Boumerdes : Institut de Genie Electrique et Electronique, 2024) Tchina, Aida; Gouigah, Feriel; Challal, Mouloud ( Supervisor)This work presents dual-band and tri-band microstrip antennas, printed on FR4 dielectric material, for Smart Grid applications. The firs tantenn ai sdesigne dt oresonat ea t2.4GH zan d3.5GH zfrequencie swhic hca nbe applicable for WLAN and WiMAX bands, respectively. Next, a triple-band antenna that can be operated in three different resonant frequencies of 0.72GHz, 1.8GHz and 2.4GHz for Wireless Energy Sensor, Cellular Communication, and WiFi respectively. The radioelectric properties of these structures, including S-parameters, current distributions, radiation patterns, and gain, were investigated using the CST electromagnetic simulator.- Prototypes of the two final structures were fabricated, and their S-parameters were measured, showing good agreement between the simulated and measured results.Item Antenna selection in massive MIMO using machine learning(Université M’hamed Bougara de Boumerdes : Institut de Genie Electrique et Electronique, 2024) Cherigui, Rahma; Bouazabia, Sarah; Boutellaa, Elhocine (Supervisor)In massive MIMO (Multiple Input Multiple Output) systems the overall performance (bit/s/Hz/cell) is significantly improved by equipping the base stations with arrays of a hundred antennas; which becomes one of its most significant challenges; economically and technically due to the high power consumption. To solve this, Antenna selection (AS) is increasingly gaining more interest, as it strategically reduces the hardware complexity while maximizing efficiency and throughput by selecting a specific subset of antennas to activate in each transmission slot. In this report, we examine the application of multi-label learning (MLL) based algorithms in AS, such as problem transformation methods, including first order binary relevance; and high order chain classification. Additionally, we investigate the Deep neural networks (DNN) based algorithms, namely Multi-Label Convolutional Neural Networks (MLCNN) and Multi-Layer Perceptron (MLP) classifier, and multi-View based algorithm. These proposed methods are rigorously evaluated based on their maximum capacity, performance and the computation time across various scenarios. Our work concludes that, in comparison with the convex relaxation based method, the Multi-view MLL achieves comparable results.