Browsing by Author "Şahinoğlu, Z."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Open Access Short-range wireless communications and reliability(Cambridge University Press, 2011) Güvenç, İ.; Gezici, Sinan; Şahinoğlu, Z.; Kozat, U. C.; Güvenç, İ.; Gezici, Sinan; Şahinoğlu, Z.; Kozat, U. C.Even though there is no universally accepted definition, short-range wireless communications typically refers to a wide variety of technologies with communication ranges from a few centimeters to several hundreds of meters. While the last three decades of the wireless industry have been mostly dominated by cellular systems, short-range wireless devices have gradually become a more integrated part of our everyday lives over the last decade. The Wireless World Research Forum (WWRF) envisions that this trend will accelerate in the upcoming years: by the year 2017, it is expected that seven billion people in the world will be using seven trillion wireless devices [1]. The majority of these devices will be short-range wireless devices that interconnect people with each other and their environments. While the reliability of wireless communication systems has been studied in detail in the past, a comprehensive study of different factors affecting reliability for short-range wireless systems and how they can be handled is not available in the literature, to date. The present book intends to fill this gap by covering important reliability problems for short-range wireless communication systems. The scope of the contributions in the book is mostly within the domain of wireless personal area networks (WPANs) and wireless sensor networks (WSNs), and issues related to wireless local area networks (WLANs) are not specifically treated. Due to the differences in application scenarios, quality of service (QoS) requirements, signaling models, and different error sources and mitigation approaches, the high-rate and low-rate systems will be addressed in separate parts of the book.Item Open Access Theoretical limits for estimation of vital signal parameters using impulse radio UWB(IEEE, 2007) Gezici, Sinan; Şahinoğlu, Z.In this paper, Cramer-Rao lower bounds (CRLBs) for estimation of vital signal parameters, such as respiration and heart-beat rates, using ultra-wideband (UWB) pulses are derived. In addition, a simple closed-form CRLB expression is obtained for sinusoidal displacement functions under certain conditions. Moreover, a two-step suboptimal solution is proposed, which is based on time-delay estimation via matched filtering followed by least-squares (LS) estimation. It is shown that the proposed solution is asymptotically optimal in the limit of certain system parameters. Simulation studies are performed to evaluate the lower bounds and performance of the proposed solution for realistic system parameters.Item Open Access Ultra-wideband range estimation: Theoretical limits and practical algorithms(IEEE, 2008-09) Güvenç, İ.; Gezici, Sinan; Şahinoğlu, Z.The high time resolution of ultra-wideband (UWB) signals enables wireless devices to perform accurate range estimation. In order to realize UWB systems with accurate ranging capabilities, both theoretical limits on range estimation and practical algorithms that approach those limits should be investigated. This paper provides a survey of various UWB ranging algorithms and discusses their performance and complexity tradeoffs. In addition, theoretical limits on range estimation are discussed in terms of Cramer-Rao and Ziv-Zakai lower bounds. Index Terms- Ultra-wideband (UWB), time-of-arrival (TOA) estimation, ranging, Cramer-Rao lower bound (CRLB), Ziv-Zakai lower bound (ZZLB). ©2008 IEEE.