Impulse radio ultra wideband over fiber techniques for broadband in-building network applications
A catalogue record is available from the Eindhoven University of Technology Library Impulse radio ultrawideband over fiber techniques for broadband in-building network applications/ by Solomon Tesfay Abraha Eindhoven: Technische Universiteit Eindhoven, 2012 Proefschrift.-ISBN: 978-90-386-3212-4 NUR 959 Trefwoorden: Opische telecommunicatie/ radio-over-glasvezel/ magnetron fotonica/ plastic optische vezel. Subject headings: optical fiber communication/ radio-over-fiber/microwave
... optical fiber. Summary Essays on Impulse Radio Ultra Wideband over Fiber Techniques for Broadband In-Building Network Applications In recent years, the demand for high bandwidth and mobility from the end users has been continuously growing. To satisfy this demand, broadband communication technologies that combined the benefit of both wired and wireless are considered as vital solutions. These hybrid optical wireless solutions enable multi-Gbit/s transmission as well as adequate flexibility in terms of mobility. Optical fiber is the ideal medium for such hybrid solution due its signal transparency and wide bandwidth. On the other hand, ultra wideband(UWB) radio over optical fiber technology is considered to be one of the key promising technologies for broadband communication and sensor network applications. The growing interest for UWB is mainly due to its numerous attractive features, such as low power spectral density, tolerance to multipath fading, low probability of interception, coexistence with other wireless services and capability of providing cost-effective > 1 Gb/s transmission. The main idea of UWB over fiber is to deliver UWB radio signals over optical channels, where the optical part serves as a backbone communication infrastructure to carry the UWB signal with a bandwidth of several GHz. This enables multiple novel applications such as: range extension of high speed wireless personal area networks (WPANs), low cost distributed antenna systems, secure and intelligent networks, or delivering broadband services to remote areas. In particular, this thesis deals with novel concepts on shaping and generation of IR-UWB pulses, theoretical and experimental demonstrations over different fiber types, routing of integrated wired/wireless IR-UWB services and effect of fiber types on ranging/localization of IR-UWB-over-fiber systems. Accordingly, this thesis investigates techniques for delivery of high data rate wireless services using impulse radio ultra wideband (IR-UWB) over fiber technology for both access and in-building network applications. To effectively utilize the emission mask imposed for UWB technologies by the Federal iv Communications Commission(FCC), novel pulse shaping techniques have been investigated and experimentally demonstrated. Comparison of the proposed pulses with conventional ones in terms of the compliance to the FCC-mask requirements, spectral power efficiencies and wireless coverage has been theoretically studied. Simple and efficient optical generation of the new pulse has been experimentally demonstrated. Furthermore, performance evaluation of 2 Gb/s transmission of IR-UWB over different types of fiber such as 25 km silica single-mode, 4.4 km silica multi-mode and 100 m plastic heavily-multi-mode fiber have been performed. To improve the functionalities of in-building networks for the delivery of wireless services; techniques that provide flexibility in terms of dynamic capacity allocation have been investigated. By employing wavelength conversion based on cross-gain modulation in optical semiconductor amplifiers(SOA), routing of three optical channels of IR-UWB over fiber system has been experimentally realized. To reduce the cost of the overall system and share the optical infrastructure, an integrated testbed for wired baseband data and wireless IR-UWB over 1 km SMF-28 fiber has been developed. Accordingly, 1.25 Gb/s wired baseband and 2 Gb/s wireless IR-UWB data have been successfully transmitted over the testbed. Furthermore, to improve the network flexibility, routing of both wired baseband and wireless signals has been demonstrated. Additionally, the ranging and localization capability of IR-UWB over fiber for in-door wireless picocells have been investigated. The effect of different fiber types (4 km SMF, 4.4 km GI-MMF and 100 m PF GI-POF) on the accuracy of the range estimation using time-of-arrival (ToA) ranging technique has been studied. A high accuracy in terms of cm level was achieved due to the combined effect of high bandwidth IR-UWB pulses, short reach fiber and low chromatic dispersion at 1300nm wavelength. Furthermore, ranging/localization using IR-UWB over fiber system provides additional benefit of centralizing complex processing algorithms, simplifying radio access points, relaxing synchronization requirement, enabling energy-efficient and efficient traffic management networks. All the concepts, design and system experiments presented in this thesis underline the strong potential of IR-UWB for over optical fiber(silica and plastic) techniques for future smart, capacity and energy-efficient broadband in-building network applications. A Overview of IR-UWB modulation schemes 156 BIBLIOGRAPY 167 B List of publications 187 List of Publications 187 viii CONTENTS Curriculum Vitae 193 Chapter 1 IR-UWB over Fiber: A System Approach In recent years, there has been growing interest for high capacity, mobility, flexibility, low cost and energy-efficient integration of wired/wireless over a single in-building optical network infrastructure in order to provide both broadband communications and sensor applications. Accordingly, IR-UWB-overfiber technology, a key enabler for merging of broadband wired and wireless IR-UWB services in high-capacity and energy-efficient in-building networks is the central investigation topic of this thesis. This introductory chapter starts with discussing the benefits of telecommunication technologies (wired and wireless) and brief overview of trends in different wireless networks in section 1.1. Then, section 1.2, presents a brief overview of the characteristics, benefits and variants of UWB techniques, followed by applications and challenges of UWB technology in section 1.3 and 1.4 respectively. The main motivation and possible applications of IR-UWB over fiber solutions are presented in section 1.5. The scope and contributions of this thesis are presented in section 1.6. Finally, the outline of the thesis is given in section 1.7.