Telecommunication

Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/3080

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Microstrip band-pass filters for dual band applications, design and implementation
(2016) Mermoul, Ali; Hocine, Kenza; Challal, M. (Supervisor)
In this work, three new different microstrip dual-band bandpass filters (BPFs) operating at (2.1 GHz, 5.1 GHz), (1.6 GHz, 5.15 GHz) and (2.45 GHz, 5.5 GHz) for 3G, Wi-Fi, WLAN and satellite communications are investigated and realized. The three filters are obtained from modified second order hairpin filter. The proposed filters present satisfactory performances and meet the requirements of modern wireless communication systems. The substrate material used for all designs is FR4 with a thickness of 1.62 mm, a relative dielectric constant of 4.3 and a dielectric tangent loss of 0.0017.
Study and simulation of the link adaptation technology in the LTE standard
(2016) Meziane, Mokrane; Allilat, Fetta; Zitouni, Abdelkader (Supervisor)
The Long Term Evolution first introduced by the link adaptation system as a massive step forward in the control of the network resources. It is mainly based on measuring instantaneous Signal to Interference and Noise Ratio (SINR) which is used to investigated the influence of several parameters on the link adaptation error characteristics. Adaptive Modulation and Coding (AMC) is used to increase the network capacity or downlink data rates. Spatial multiplexing techniques for MIMO antenna configurations are also considered. This report has outlined the various scheduling techniques used in the link adaptation process to increase the throughput of the network. Three major channel state report measurements are used to perform the adaptations which are: CQI (channel quality indicator), PMI (Precoding Matrix Indicator), and RI (Rank Indicator) measurements. An analysis and a comparison of these scheduling algorithms were done through simulations executed on MATLAB software. The impact of the scheduling schemes was examined on the throughput (Average Data Rate) and the Bit Error Rate (BER), and it was compared to the case where no adaptation is done. The fairness of the results given by each scheduling scheme was investigated. The link adaptation improved the transmission robustness through minimizing the error and increased the spectral efficiency to produce a satisfactory average data.
Digital Filters for reducing the effects of dispersion in optical communication
(2016) Grainat, Youcef; Mebarki, Yaser; Zitouni, Abdelkader (Supervisor)
The aim of this project is to use digital filters to reduce the effects of dispersion in modern WDM optical communication systems at two transmission speeds, 2.5 and 5 Gbps. For this purpose two types of filters [Gaussian Filter (GF) and Cosine Roll Off Filter (CROF)] have been tested by simulation using OptiSystem and Matlab in single mode fiber links at the operating wavelength of 1550 nm. From the obtained results a comparative study with respect to the conventional Dispersion Compensating Fibers (DCF) has been carried out.
A study and optimization of the JPEG2000 image compression algorithm
(2016) Boumedine, Ahmed Yassine; Nehar, Sallah Eddine; Kerouh, Fatma (Supervisor)
The aim of this project is to study and optimize JPEG2000 compression algorithm. JPEG2000 is a compression standard that uses wavelet transform. A color space transformation is first achieved, then the compression process in the wavelet domain is applied. Our purpose is to find the optimal color space, optimal wavelet, and optimal resolution level to compress any image. To carry out the experiments, the basic JPEG2000 algorithm is first implemented using MATLAB software. Then, tests are performed on different images selected from a free database named LIVE. For the study, three color spaces have been considered, Red, Green, Blue (RGB), Luminance/ Chrominance (YCbCr), and Hue/ Saturation/ Value (HSV). Furthermore, different wavelets and resolution levels have been considered. The compressed images are evaluated in terms of compression ratio, Detail Index (DI), and three quality metrics a full reference spatial metric named PSNR (Peak Signal to Noise Ratio), structural quality metric named MS-SSIM, and a blur metric (IQA).
FIR filter design using optimization algorithms
(2016) Zebara, Oussama; Bouhamoum, Youcef Zakaria; Daamouche, A. (Supervisor)
FIR Filters are used, nowadays, in different applications because of their phase linearity as well as their intrinsic stability. But for designing near optimal FIR Filters complex mathematical calculations are required, especially for high order FIR Filters. In this report we try to rely on two evolutionary algorithms, namely Particle Swarm Optimization (PSO) and Cuckoo Search Algorithm (CS), to solve this problem using simple procedures. Given the desired specifications to be met by the filter, simple procedures are used to optimize the coefficients approximating the ideal specifications and each algorithm uses its own rules to explore the search space efficiently. The results obtained are compared to PM algorithm in order to assess the performance of the proposed procedure in terms of the magnitude of ripples, transition band and convergence rate.
Study of plus slotted microstrip antenna for wireless applications
(2016) Bencharef, Fatma Zohra; Haouchine, Leila; Azrar, Arab (Supervisor)
This project deals with the design and simulation of a New Microstrip Patch Antenna using IE3D software. The designed antenna was given a name of "Plus Antenna for Wireless Applications". A rectangular antenna with an operating frequency of 2.4 GHz has been studied at the beginning. Later, the rectangular shape is modified to Plus Shaped Antenna and its study has shown two frequencies. The analysis is then extended to Plus Shaped Antenna loaded by two slots. The obtained results show that the antenna can operate at to 1.72 GHz that can be used in third generation 3G application and 2.98GHz useful in WiMax applications. In addition, the reduction in the operating frequency from 2.4 GHz to 1.72 GHz has allowed size reduction of the structure of about 52%.
Text dependent speaker recognition using HTK
(2016) Bouguerra, Sara; Sahmi, Nacera; Dahimene, Abdelhakim (supervisor)
The objective of the project is to design a text dependent speaker recognition system using HTK, the HTK toolkit is used essentially for speech recognition, after understanding the theory of Hidden Markov Models, and the different processes HTK uses during recognition, the principle of Log likelihood probability, and the language Model are linked together to identify the speaker of an intended sentence chosen by the user and trained by the speaker wanted to be recognized. After several experiments, many threshold options were used, till arrived to the kinds of threshold playing a major role in speaker identification, a method for choosing thresholds has been formulated and it was applied for 10 speakers. The method for speaker identification worked successfully for all speakers, and the goal of recognizing a sentence that belongs to a particular speaker has been realized.
Comparative study of unencoded MIMO systems.
(2016) Khezzane, Yacine; Seridi, Mohammed Fekhreddine; Dahimene, Abdelhakim
Study of rectangular microstrip antenna with parasitic element
(2016) Kechir, Sabrina; Nabti, Ali; Azrar, A. (Supervisor)
The objective of the present project is the study of the effect of a parasitic patch electromagnetically coupled to a rectangular patch via its radiating edge. At the beginning, the conventional rectangular microstrip antenna is designed at the operating frequency of 2.45 GHz and simulated using IE3D. Then the work is extended to the simulation of the same rectangular patch loaded by a parasitic element with same dimensions. It has been found that the addition of the parasitic results in a larger bandwidth due to the overlapping of the two resonant frequencies. At the end, the effect of varying the distance between the two patches and the length of the parasitic patch is simulated and studied.
Design and implementation of an ultra-wide stopband microstrip Low-Pass Filter
(2016) Badaoui, Ayoub; Hachour, Ferhat; Challal, M.(Supervisor)
In this project, a microstrip low pass filter (LPF) with wide rejection band, low insertion loss and compact size is investigated. The designed LPF is composed of three open stubs, three identical new shapes (named hourglass) and two rectangular shapes etched in the ground plane. The proposed LPF has acceptable performances in terms of insertion loss, less than 1.5 dB, return loss in the pass-band, less than 9.5 dB, wide stop-band at -20 dB suppression level ranging from 3.88 GHz to more than 20 GHz and size of 35x14 mm 2 .
Study and simulation of the optical impairments in a CO-OFDM/RoF system
(2016) Anbar, Lahcene; SadaliI, Soraya; ZitouniI, Abdelkader (Supervisor)
One of the most advanced and attracting technologies in optical fiber communication systems that support efficient convergence of wireless and optical access network structure is Radio over Fiber (RoF). In RoF, light is modulated by using a radio signal and sent over an optical fiber link to simplify wireless access. As the demand for high-speed wireless communications is increasing rapidly, Coherent Optical Orthogonal Frequency Division Multiplexing (CO-OFDM) technology is considered to be a fundamental technique to satisfy this need. The aim of this project is to investigate through simulation the impairments due to the integration of CO-OFDM with RoF for achieving high data rates over long haul optical fiber systems. Solutions to combat the attenuation as well as the dispersion effects on such systems have been proposed and tested.
Fusion of voice and face using artificial neural networks at feature level
(2016) El Affifi, Omar Badis; Boushaba, Saddek; Cherifi, Dalila (Supervisor)
Lately, human recognition and identification has acquired much more attention than it had before, due to the fact that computer science nowadays is offering lots of alternatives to solve this problem, aiming to achieve the best security levels. One way is to fuse different modalities as face, voice, fingerprint and other biometric identifiers. The topics of computer vision and machine learning have recently become the state-of-the-art techniques when it comes to solving problems that involve huge amounts of data. One emerging concept is Artificial Neural networks. In this work, we aim to use both human face and voice to design a multibiometric recognition system, the fusion is done at the feature level with three different schemes namely, concatenation of pre-normalized features, merging normalized features and multiplication of features extracted from faces and voices. The classification is performed by the means of an Artificial Neural Network. The system performances are to be assessed and compared with the K-nearest-neighbor classifier as well as recent studies done on the subject. An analysis of the results is carried out on the basis Recognition Rates and Equal Error Rates.
Ultra large band printed monopole antenna
(2016) Settou, Noureddine; Zouari, Ferhat; Dehmas, Mokrane (Supervisor)
In this work, an Ultra Large Band modified circular shape printed monopole antenna operating in the frequency range extending from 2.60 GHz to 12.15 GHz has been developed. This is achieved by first introducing to the considered original circular shaped antenna defects that resulted in a simulated ULB behavior. The obtained monopole structure has been fabricated and its reflection coefficient measured. A good agreement is observed with the simulated results. The measured antenna percent bandwidth is 129 % whereas the simulated one is 149%. In addition, the antenna simulated and measured refection coefficients present a quite similar form over the frequency range where a good impedance matching is observed. The antenna can operate in different frequency bands (S, C and X) and hence, it is suitable for the various applications covered by these bands. Moreover, different radio electric properties including input impedance, current distribution as well as 2D and 3D radiation patterns are simulated using the CST Microwave Studio tool.
Study and imulation of the MIMO enabling technology in the LTE system
(2016) Bammoune, Nabil; Belaid, Abdelmadjid; Zitouni, A. (Supervisor)
Multi-antenna (MIMO) techniques are reported to improve the performance of radio communication systems in terms of their capacity and spectral efficiency. Long Term Evolution(LTE), one of the candidates for fourth generation(4G) mobile communication systems has MIMO as one of its underlying technologies and ITU defined channel models for its propagating environment. This project undertakes a comprehensive verification of the performance of spatial multiplexing MIMO in the downlink sector of LTE. The study and the analysis is done by the use of models built using MATLAB and Simulink to carry out simulations. It is deduced that spatial multiplexing improves spectral efficiency and increases data rate of the transmission. This is more pronounced if more antennas are used in the transmitter and the receiver. Furthermore, precoding operation for open loop and closed loop spatial multiplexing depends on the channel conditions.
Low density parity check coding
(2016) Brahimi, Mohamed Amine; Younsi, Bilel; Dahimene, Abdelhakim (Supervisor)
Since their rediscovery by Mackay Neal in 1993 [11], LDPC codes have been an integral part of the coding field, and by now, they have been in many standards and are suggested for others. In terms of performance, many practical results have shown that those codes are actually very performant at rates that are within a fraction of capacity. In this Master Project report, the general theory of LDPC codes, including construction, encoding and decoding procedures, is reviewed in the first chapters. In the simulation chapter, we consider the evaluation of error performance of short to medium length LDPC codes with BPSK modulation through the binary AGWN channel.
Hidden biometrics for identification using ECG and EEG signals
(2016) Adjerid, Chaouki; Boukerma, Billal; Cherifi, .Dalila (supervisor)
Security concerns increase as the technology for falsification advances and biometrics provides airtight security by identifying an individual based on the physiological and/or behavioral characteristics. Physiological hidden biometrics represented by ECG and EEG biomedical signals are highly confidential, sensitive, and hard to steal and replicate, and also hold great promise to provide a more secure biometric approach for user identification and authentication. This work proposes the human heartbeat as a characteristic to be used for identity recognition. An ECG-based biometric identification system is developed, a method based on autocorrelation (AC) in conjunction with the discrete cosine transform (DCT) proposed for feature extractions from the pre-processed ECG signal. Also studied is the scenario where the proposed system deals with intruder signals in our database. For this goal, a study is performed to adjust the parameters allowing the system to avoid detection failure of false identification and false rejection scenarios. In addition, human brain activities represented by EEG are studied for biometric system purposes. In this study, an EEG-based biometric system is represented by performing a pre- processing stage on the EEG signals, with the features extractions completed using a wavelet packet decomposition and a classification.
Study and realization of a multiband microstrip antenna
(2016) Rami, Youcef; Haffadh, Hichem; Dehmas, Mokrane (Supervisor)
A microstrip patch antenna having the shape of the letter Z written in the Berber language Tifinagh transcription has been simulated in previous works and it has been noticed that it exhibits interesting multiband features. However, all carried analyses were confined in the theoretical and simulation aspects and were not validated experimentally. In this work, this antenna shape is reconsidered in the frequency range extending up to 6 GHz and simulated taking into account practical considerations related to used materials and experimental aspects. The antenna dimensions and configuration have been modified accordingly to meet desired resonant frequencies. After that, the developed structure was fabricated and its return loss measured. Though the oldness of the used substrate board, a good agreement is obtained between simulation and experimental results; the simulated resonant frequencies are located at 0.96 GHz, 2.45 GHz and 4.11 GHz whereas the measured ones were at 0.97GHz, 2.56 GHz and 4.22 GHz. Also, a similar and adequate impedance matching is observed in both simulated and experimental results. The developed antenna can be used in various applications such as GSM and Wi-Fi/WLAN.
Investigation of multiband microstrip bandstop filters with and without SMD capacitors
(2018) Boukhalfa, Ammar; Mekati, Bilal; Challal, Mouloud (Supervisor)
This work presents the design of multiband bandstop filters (BSFs) based on defected ground structure (DGS) technique. The filters are loaded by surface-mount device (SMD) capacitors for dual and triple stopbands operated at 3.69/7.63 GHz and 3.2/5.56/7.28 GHz, respectively. An additional BSF structure without SMD capacitors operated at 3.77/7.16 GHz is as well designed and fabricated. Due to their satisfactory stopband performances, the proposed filters can be useful for various communication systems with dual and triple bands rejection for WiMAX/C bands.
Design of elliptic antenna arrays using gray wolf optimization
(2018) Traikia, Oussama; Recioui, Abdelmadjid (Supervisor)
In this work, Grey Wolf Optimization (GWO) is applied to the elliptical and concentric elliptical antenna arrays to minimize the Side lobe and to improve the directivity. GWO is a nature-inspired meta-heuristic algorithm inspired by the social hierarchy and hunting behavior of grey wolves. The obtained optimal values result in a good reduction of the side lobe level for the elliptical and concentric elliptical antenna arrays with an enhancement in the directivity. This makes the designed arrays of practical use in the communication systems.
Spectral-spatial features for hyperspectral image classification
(2018) Mounir, Zakaria; Merouani, Mawloud; Daamouche, A. (Supervisor)
Image classification is one among important branches of artificial intelligence field. Generally, it translates the information contained in images into thematic categories which are suitable for use in many applications using low-level visual features. Nowadays, there exists a large number of machine learning algorithms used for image classification. The main objective of this work is to perform a classification of hyperspectral data by means of spectral-spatial features. The principle component analysis was exploited as a tool to decorrelate and reduce the dimension of the original hyperspectral data. The mathematical morphology is used to extract the spatial features; its parameters were generated empirically. The combination of the morphological features and the spectral features were fed to the state-of-the-art classifier which is the Support Vector Machines (SVM). The obtained results over two benchmark datasets show that the achieved performance using the developed method is promising.