العلم العراقي
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نتائج البحث: 4 من أصل 4

منظومة المراقبة والسيطرة لمحطات توليد الطاقة الكهربائية العراقية المبنية على بروتوكول الانترنت == INTERNET PROTOCOL BASED MONITORING AND CONTROL SYSTEM FOR IRAQI POWER GENERATION STATIONS

اسم المؤلف: سهيل نجم عبيد القيسي
اسم المشرف: Nassir N. Khamiss
الموضوع العام: هندسة الكهرباء والالكترون والاتصالات
السنة: 2008
الموضوع الدقيق: هندسة الاتصالات
الدرجة: ماجستير
الجامعة: جامعة النهرين - كلية الهندسة - قسم الهندسة الالكترونية والاتصالات
اللغة: الانكليزية
مكان الجامعة: بغداد

تحليل الاتصال بين القمر الصناعي والطائرة باستخدام نموذج تعقب الشعاع == Analysis of Satellite - To - Aircraft Communications Using Ray Tracing Model

اسم المؤلف: علي محمد علي
اسم المشرف: جابر سلمان عزيز
الموضوع العام: هندسة الكهرباء والالكترون والاتصالات
السنة: 2008
الموضوع الدقيق: هندسة الاتصالات
الدرجة: ماجستير
الجامعة: جامعة النهرين - كلية الهندسة - قسم الهندسة الالكترونية والاتصالات
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: While the aircraft flying above the earth surface, the signal transmitted from the satellite to the aircraft suffered from changes in it's characteristics at the aircraft receiver's antenna according to many factors affecting the direct and reflected power from the earth surface such as the distance difference, the nature of the earth surface, elevation angle, Doppler shift, etc… This Thesis introduces a proposed algorithm to analyze and simulate the communication link between the Satellite and the aircraft taking into account all the parameters that affect the magnitude of the power and signal characteristics received at the aircraft antenna. The proposed method uses the ray - tracing technique in this simulation to analyze the communication link between the Satellite and aircraft. The simulation developed in this thesis has minimized the error percentage as much as possible taking into account most of the factors that might affect the characteristics of the signal received by the aircraft from the satellite. This simulation considers the free space loss, specular reflection losses, scattering factor, earth curvature effect, etc…,also the simulation takes into account the Doppler effect that caused by the aircraft movements. The simulation measures the received signal strength and fading characteristics of satellite to aircraft communication to determine the effectiveness of communication and to establish parameters which can be useful to the communication system designer in Iraq and the rest of the world. MATLAB® v6.5 used in the simulation as application software, the simulation also applied to MATLAB® v7.0.

محاكاة تضمين تقسيم التردد المتعامد المتعدد المستخدمين المشفر في الخط النازل == Simulation of Coded Multiuser Ofdm Downlink

اسم المؤلف: دﻧﻴﺎ ﻓﺆاد فاروق النعيمي
اسم المشرف: رعد سامي فياض
الموضوع العام: هندسة الكهرباء والالكترون والاتصالات
السنة: 2008
الموضوع الدقيق: هندسة الاتصالات
الدرجة: ماجستير
الجامعة: جامعة النهرين - كلية الهندسة - قسم الهندسة الالكترونية والاتصالات
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: The orthogonal frequency division multiple access (OFDMA) scheme adopts orthogonal frequency division multiplexing (OFDM) subcarriers, which are particularly suited for transmition over broadband frequency selection channels, to support multiusers. The scheme considered usually assigns a subset of subcarriers to each user and adopted adaptive techniques for the allocation of available resources/subcarriers according to the channel state information (CSI) estimated at the transmitter using a reverse link. This thesis proposed three coded multiuser OFDM schemes based on spreading the data of each user over all subcarriers without CSI at the transmitter. The idea behind these schemes is to split the OFDM transceiver into two stages : one common to all users while the other consists of identical parallel units with each unit is used to process the data related to an individual user. The two stages are separated by a multiplexer/demultiplexer unit whose position can be chosen to yield different schemes. The three schemes considered here are : user multiplexed scheme, inner coded multiplexing scheme, and mapper multiplexing scheme. The proposed schemes implemented are using MATLAB simulink (version 7) to investigate their performance under different operating conditions related to number of users, Rayleigh fading channel, and serial concatenated codes. The results are compared with those related to two conventional schemes, subcarrier mapping scheme and outer coded multiplexing scheme. The simulation results indicate that the proposed user multiplexing scheme may offer performance as high as that offered by the conventional outer coded multiplexing scheme but with reduced number of equipments.

تهيئة حاسوبية لموجه سيسكو == Computer Based Configuration For Cisco Routers

اسم المؤلف: فارتان رافي كريكوريان
اسم المشرف: غسان حميد عبد المجيد
الموضوع العام: هندسة الكهرباء والالكترون والاتصالات
السنة: 2008
الموضوع الدقيق: هندسة الاتصالات
الدرجة: ماجستير
الجامعة: جامعة النهرين - كلية الهندسة - قسم الهندسة الالكترونية والاتصالات
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: Routers are intelligent devices that make connection between different networks possible. In addition, routers can perform several functions, including filtration and selection of the best path of packets movement. Routers must be configured efficiently in order to perform the above functions. In literature, two approaches have been distinguished for the configuration, namely; text mode and graphical mode approach. The present work is analyzing these two approaches and defines precisely their advantages and limitations. As a result of this analysis, a new approach is proposed in this thesis which eliminates the limitations. The work proposes a graphical interface which is executed on a desktop (or laptop) PC. The user defines the configuration parameters through a program which transfers these parameters to the router by console port instead of Ethernet port. These parameters are then saved on Non Volatile Random Access Memory. The proposed graphical interface is implemented by standard lab consisted of two routers. The implementation shows that the time of configuration can be reduced to 70% of the text mode approach, and overcome the trouble of the old graphical interface.