رسالة جامعية
Υπολογιστική ανάλυση της διάδοσης ηλεκτρομαγνητικών κυμάτων σε ασύρματες επικοινωνίες εσωτερικού χώρου ; Computational analysis of electromagnetic wave propagation in wireless indoor communications
| العنوان: | Υπολογιστική ανάλυση της διάδοσης ηλεκτρομαγνητικών κυμάτων σε ασύρματες επικοινωνίες εσωτερικού χώρου ; Computational analysis of electromagnetic wave propagation in wireless indoor communications |
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| المؤلفون: | Theofilogiannakos, Georgios, Θεοφιλογιαννάκος, Γεώργιος |
| بيانات النشر: | Aristotle University Of Thessaloniki (AUTH) Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ) |
| سنة النشر: | 2009 |
| المجموعة: | National Archive of PhD Theses (National Documentation Centre Greece) |
| مصطلحات موضوعية: | Μέθοδος παραβολικής εξίσωσης, Μέθοδος ολοκληρωτικών εξισώσεων, Μέθοδος παρακολούθησης ακτίνων, Κυματική διάδοση, Επικοινωνίες εσωτερικού χώρου, Ασύρματα τοπικά δίκτυα, Επικονωνίες σε αστικό περιβάλλον, Ασύρματα μητροπολιτικά δίκτυα, Parabolic equation method, Integral equation method, Ray-tracing method, Wave propagation, Indoor communications, Wireless lans (wlans), Urban communication, Wireless metropolitan area networks, Επιστήμες Μηχανικού και Τεχνολογία, Επιστήμη Ηλεκτρολόγου Μηχανικού, Ηλεκτρονικού Μηχανικού, Μηχανικού Η/Υ, Engineering and Technology, Electrical Engineering, Electronic Engineering, Information Engineering |
| الوصف: | Network planning in modern wireless communications is important to maximize efficiency, cost reduction, security and compliance with safety regulations. For this reason, computational models are often employed to predict the electromagnetic field distribution, fading and multipath characteristics of indoor channels. The primary methods of choice in indoor channel simulations definitely belong to the class of ray-tracing techniques. These are based on canonical models of wave reflection, refraction and diffraction and, as expected, they require a large number of rays to provide a good approximation. In this thesis we propose an alternative method which combines a wide-angle parabolic equation (PE) multistep scheme, based on a Pade approximation of the forward wave equation and a fast Green’s function formulation. At a first step, the PE is used to calculate an estimate of the electromagnetic field in the interior of the elements comprising the building structure. The PE effectively decomposes the 3D problem in a series of 2D problems, successively solved by a marching-in-space approach. Still, there are quite important propagation rays that are not taken into account, such as all backward reflected, diffracted or scattered waves. Hence, a second step is employed to introduce a proper correction of the field by a Green’s function approach, using the induced equivalent currents within the walls and other structures, computed by the PE technique, as secondary sources. The resulting correction is, thus, fast and does not involve a matrix system solution. For the validation of this method, the scattering from a dielectric cylinder and sphere has been analyzed. Then, in need of a better validation of the method, we have chosen to model, a realistic office space consisting of twelve rooms, on the same floor, having a total area of 535m2. Two different frequencies of 1 and 2.5GHz have been considered, representing two of the most common frequency bands for present and future mobile and wireless communication systems. The ... |
| نوع الوثيقة: | doctoral or postdoctoral thesis |
| اللغة: | Greek, Modern (1453-) |
| العلاقة: | http://hdl.handle.net/10442/hedi/19249Test |
| DOI: | 10.12681/eadd/19249 |
| الإتاحة: | https://doi.org/10.12681/eadd/19249Test http://hdl.handle.net/10442/hedi/19249Test |
| رقم الانضمام: | edsbas.268A75B2 |
| قاعدة البيانات: | BASE |
| DOI: | 10.12681/eadd/19249 |
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