Zur Kapazitätserhöhung in zellularen Mobilfunksystemen eignet sich der Einsatz adaptiver Antennen an der Basisstation. Diese ermöglichen die räumliche Wiederverwendung von Kanälen innerhalb einer Zelle mittels Space Division Multiple Access (SDMA). Die Kapazitätsgewinne, die mit SDMA zu erzielen sind, hängen jedoch stark von den verwendeten Verfahren des Ressourcen Managements (RM) ab. Hierzu wurden neuartige RM-Verfahren für SDMA-Systeme entwickelt, welche die räumliche Kanalwiederverwendung innerhalb der Zelle mit verschiedenen Prinzipien der interzellularen Kanalvergabe (statische und dynamische) kombinieren. Zudem wurden die entwickelten Verfahren erweitert, um auch in hierarchisch strukturierten zellularen Netzen eingesetzt werden zu können. In ausführlichen Systemsimulationen konnte gezeigt werden, dass die neuen RM-Verfahren eine Vervielfachung der Systemkapazität mit Hilfe von SDMA ermöglichen. Zusätzlich werden analytische Modelle entwickelt und ausgewertet, die den Gewinn von Verfahren vorhersagen, welche die durch die Verwendung adaptiver Antennen reduzierte Inter-Zell-Interferenz ausnutzen (Spatial Filtering for Interference Reduction-SFIR), dies wird sowohl für F/TDMA basierte Systeme als auch für CDMA Systeme analysiert.

The aim of this thesis is to introduce a non-stationary model for the scattering in mobile-to-mobile channels. Due to the evolution of wireless technology, fixed-to-mobile communications systems are nowadays complemented by mobile-to-mobile communications systems. In the vehicular sector, mobile-to-mobile communications systems are used to enable intelligent transportation systems. Such systems aim to make transportation safer and more efficient by distributing sensor information among the cars. In the aeronautical sector, mobile-to-mobile communications systems will be used, for example, to exchange position, altitude, speed, and heading data between aircraft during flight thus allowing for a reduced separation between them. Hence, these systems are necessary to further increase the air traffic density.

With around 3 billion subscribers, GSM is the world's most commonly used technology for wireless communication. Providing an overview of the innovations that have fuelled this phenomena, GSM: Architecture, Protocols and Services, Third Edition offers a clear introduction to the field of cellular systems. Special emphasis is placed on system architecture and protocol aspects, and topics range from addressing concepts through mobility management to network management. This third edition contains around 25% new and reworked material and has been thoroughly updated to encompass recent advances and future trends. It serves as both an introductory textbook for graduate students as well as a reference resource for telecommunications engineers and researchers. This edition: Presents capacity enhancement methods like sectorization, the application of adaptive antennas for Spatial Filtering for Interference Reduction (SFIR) and Space Division Multiple Access (SDMA) Provides a detailed introduction to GPRS, HSCSD, and EDGE for packet-switched services and higher data rates Features updated coverage on the vastly expanded range of GSM services, including an examination of Multimedia Messaging Service (MMS) Adopts a highly graphical approach with numerous illustrations

Mobile Ad hoc NETworks (MANETs) has attracted great research interest in recent years. A Mobile Ad Hoc Network is a self-organizing multi-hop wireless network where all hosts (often called nodes) participate in the routing and data forwarding process. The dependence on nodes to relay data packets for others makes mobile ad hoc networks extremely susceptible to various malicious and selfish behaviors. This point is largely overlooked during the early stage of MANET research. Many works simply assume nodes are inherently cooperative and benign. However, experiences from the wired world manifest that the reverse is usually true; and many works [3] [10] [9] [8] [12] [19] have pointed out that the impact of malicious and selfish users must be carefully investigated. The goal of this research is to address the cooperation problem and related security issues in wireless ad hoc networks. As a rule of thumb, it is more desirable to include security mechanisms in the design phase rather than continually patching the system for security breaches. As pointed out in [2] [1], there can be both selfish and malicious nodes in a mobile ad hoc network. Selfish nodes are most concerned about their energy consumption and intentionally drop packets to save power. The purpose of malicious nodes, on the other hand, is to attack the network using various intrusive techniques. In general, nodes in an ad hoc network can exhibit Byzantine behaviors.

Of Non-Wraparound Network Performance -- Wrap-around Network Performance Results -- Performance Results over a LOS Channel -- Performance Results over a Multipath Channel -- Performance over a Multipath Channel using Power Control -- Performance of an AQAM based Network using Power Control -- UTRA, Adaptive Arrays and Adaptive Modulation -- Direct Sequence Code Division Multiple Access -- UMTS Terrestrial Radio Access -- Spreading and Modulation -- Common Pilot Channel -- Power Control -- Uplink Power Control -- Downlink Power Control -- Soft Handover -- Signal-to-Interference plus Noise Ratio Calculations -- Downlink -- Uplink -- Multi-User Detection -- Simulation Results -- Simulation Parameters -- The Effect of Pilot Power on Soft Handover Results -- Fixed Received Pilot Power Thresholds without Shadowing -- Fixed Received Pilot Power Thresholds with 0.5 Hz Shadowing -- Fixed Received Pilot Power Thresholds with 1.0 Hz Shadowing -- Relative Received Pilot Power Thresholds without Shadowing -- Relative Received Pilot Power Thresholds with 0.5 Hz Shadowing -- Relative Received Pilot Power Thresholds with 1.0 Hz Shadowing -- E[subscript c]/I[subscript o] Power Based Soft Handover Results -- Fixed E[subscript c]/I[subscript o] Thresholds without Shadowing -- Fixed E[subscript c]/I[subscript o] Thresholds with 0.5 Hz Shadowing -- Fixed E[subscript c]/I[subscript o] Thresholds with 1.0 Hz Shadowing -- Relative E[subscript c]/I[subscript o] Thresholds without Shadowing.

This book will be a comprehensive collection of advanced concepts related to 4th generation wireless communication systems. It will be divided into two main parts: resource allocation and transceiver architectures. These two research areas are at the core of the recent advances experimented by wireless communication systems. Each chapter will cover a relevant, timely, topic with two focuses: a first part which is of tutorial and survey nature, reviews the state of the art in that topic, followed by a more deep treatment including current research topics, case studies and performance analysis.

In June 2000, GTEL (Wireless Telecommunications Research Group) at the F- eral University of Ceara ́ was founded by Professor Rodrigo Cavalcanti and his c- leagues with the mission of developing wireless communications technology and impact the development of the Brazilian telecommunications sector. From the start, this research effort has been supported by Ericsson Research providing a dynamic environment where academia and industry together can address timely and relevant research challenges. This book summarized much of the research output that has resulted from GTEL’s efforts. It provides a comprehensive treatment of the physical and multiple access layers in mobile communication systems describing different generations of systems but with a focus on 3G systems. The team of Professor C- alcanti has contributed scienti cally to the development of this eld and built up an impressive expertise. In the chapters that follow, they share their views and kno- edge on the underlying principles and technical trade-offs when designing the air interface of 3G systems. The complexity of 3G systems and the interaction between the physical and m- tiple access layers present a tremendous challenge when modeling, designing, and analyzing the mobile communication system. Herein, the authors tackle this pr- lem in an impressive manner. Their work is very much in line with the developments in 3GPP providing a deeper understanding of the evolution of 3G and also future enhancements.

CD-ROM contains: RUNE (Rudimentary Network Emulator) software

These papers from RAWCON '98 offer an interdisciplinary focus at the intersection between radio-frequency and communications engineering. Topics include: broadband wireless systems concepts; system architecture and networking; and system modelling and measurement.