In this thesis we investigate the performance of spatial reuse in wireless networks. More specifically, we investigate the performance of location-based spatial reuse built upon the identification of links in the network that form Collision-Free Sets (CFSs). We develop algorithms that efficiently find such CFSs. The main focus of this thesis is the application of our CFS-based algorithms to emerging WiMAX (Worldwide Interoperability for Microwave Access) networks. However, we will also apply our CFS-based algorithms to smaller scale networks, as well as to the issue of QoS routing. This thesis makes several contributions. We first show how CFSs can be found within polynomial time in small scale wireless networks. We then probe how CFSs can be used to enhance network efficiency when location is available. We also explore how CFS determination is affected by location error, determining what level of location error renders the use of CFSs ineffective. In this context, we discuss the density of access points required to ensure CFS-based spatial reuse remains effective. We then focus on the use of CFSs in emerging multihop WiMAX networks, showing in detail how enhanced spatial reuse is delivered. The spatial reuse gains are probed both in the presence of realistic channel conditions and realistic location errors. Within the context of the IEEE 802.16 standard we show how CFSs can enhance, by factors of two, the VoIP capacity of multihop WiMAX networks. We also discuss how our CFS algorithms can be applied to other ongoing efforts aimed at improving VoIP capacity in WiMAX networks. Finally, an application of our CFS algorithms in the context of QoS routing is studied. Specifically, we develop a two-hop QoS routing protocol that guarantees QoS specifications by securing higher bandwidth for the chosen routes.

Highly reliable and fast wireless communication services demand the communication channel capacity to be fully exploited. Vast amount of research effort have been expanded in the development of advance technologies, such as signal processing, channel coding, modulation/demodulation, diversity techniques, and so on. This thesis focuses on the development of space-time coded transmission schemes. In order to provide high diversity gain with minimum design complexity, we propose a closed-loop beamforming transmission technology combined with existing simple channel coding method. We show that this coded beamforming scheme can achieve full diversity as the space-time coding technique does for a multiple-antenna system, while significantly reducing the design complexity. It is normally impractical to install multiple antennas on a small wireless communication device. We therefore further our research to cooperative communication, in which single-antenna communicators share their antennas with partners in information relay, so that the benefit of multiple-antenna transmission can be achieved for the singleantenna users. We analyze the system performance for the typical decode-and-forward user cooperative system, formulate the code design criteria, and construct optimal codes. To simplify the system design, we introduce estimate-and-forward protocol with differential modulation scheme. In order to ensure the practicality of the system design, we introduce an equivalent link model to replace the source-relay-destination link, taking into account the imperfect detections at the relay. Finally we extend the analysis to a multiple-relay system using selective combiner at the destination.

Bibliography: leaves 211-227. / xv, 227 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Aims to improve the design and performance of Reservation based Time Division Multiple Access protocols for Wireless Personal Communications. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1998

The ever-increasing demand for higher information-transfer rates in wireless data networks invokes the need to develop more spectrally-efficient communication strategies. Techniques such as MIMO and turbo-coded CDMA are well known and obvious candidates for improving the spectral efficiency of next-generation wireless networks, and addressing the limitations of currently implemented technologies. Correspondingly, such methods are finding their way into wireless network standards such as 3GPP and IEEE 802.20. One measure of the size of a communication system is the number of independent data streams being transmitted simultaneously through a channel, assuming tight constraints on available bandwidth and signal power. Such data streams may originate from different users all wishing to communicate at once. In addition, each user may wish to transmit independent data on more than one antenna simultaneously in order to increase his or her own data rate. Although strategies for such multi-dimensional signalling have seen significant improvements in recent years, most of the techniques proposed in the literature still suffer from either poor performance or prohibitive complexity when the size of the system grows large. This thesis is concerned primarily with supporting high systemspectral-efficiencies in very large systems, while maintaining strong resistance to data errors with manageable complexity. / thesis (PhDTelecommunications)--University of South Australia, 2004.

The ever increasing demand for wireless services using mobile cellular communication technology has lead to intensive efforts by researchers to determine the information theoretic limitations of these systems. Toward this end, numerous cellular models have been formulated and analyzed using information theoretic principles to succinctly identify the impact of system constraints and design parameters on performance. One such model that captures the essence of the uplink of a cellular channel is the Gaussian cellular multiple access channel (GCMAC), which is the focus of this dissertation. / Thesis (PhD)--University of South Australia, 2006

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 28, 2008) Includes bibliographical references.

Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: Xiaolin Wu. Includes bibliographical references (leaves 102-107).

Thesis (Ph.D.)--Tufts University, 2004. / Adviser: Lee McKnight. Submitted to the Dept. of Interdisciplinary Studies. Includes bibliographical references (leaves 368-382). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (MScIng)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (MScIng)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.