Thesis (M.S.)--Ohio University, November, 1996. / Title from PDF t.p.

Thesis (M.S.)--Ohio University, November, 1995. / Title from PDF t.p.

Thesis (M.S.)--Ohio University, November, 2003. / Includes bibliographical references (p. 59).

Thesis (Ph. D.)--University of Hong Kong, 1998. / Includes bibliographical references.

Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 108-110). Also available in electronic format on the Internet.

Thesis (Ph.D.) - Carleton University, 2007. / Includes bibliographical references (p. 213-224). Also available in electronic format on the Internet.

Thesis (M.S.)--Ohio University, November, 2003. / Title from PDF t.p. Includes bibliographical references (p. 59)

Joseph Y.N. Hui. / Bibliography: p. [5] / "September 1984." Reprinted from IEEE Journal on Selected Areas in Communications, vol. SAC-2, no.4, July 1984. / "... supported by the National Science Foundation under Grant NSF/ECS 78-19880..." "... Advanced Project Agency under Grant ONR-N00014-75-C1183."

Spread spectrum techniques offer an alternate solution to the urgency for distributed optical fiber sensors. These techniques are based on the properties of pseudorandom sequences that have triangular autocorrelation functions with peaks only at regions of no delay. This affords an opportunity to give the desired signal a power advantage over many types of interference and noise. A study in employing spread spectrum techniques for multiplexing optical fiber sensors is presented. A mathematical analysis of the system is conducted with due consideration given to performance issues. Simulations in software are conducted to characterize system performance. Hardware developed for this project operates at over 1 Mbps and is capable of simultaneously monitoring four sensors. Real time experiments conducted on these multiplexed sensors affirm the technical feasibility of the system. Configurations for viable applications of the system are also suggested. / Master of Science

Spread spectrum techniques have a number of different applications, including range finding, synchronisation, anti-jamming systems and multiple access communication systems. In each of these applications the properties of the resulting systems depend heavily on the family of spreading sequences employed. As such, the design of spreading sequences is an important area of research. Two areas of spreading sequence design are of particular interest in this work, combination techniques and Interference Free Window (IFW) sequences. Combination techniques allow a new sequence family to be constructed by combining two or more existing families. Such an approach allows some of the desirable properties of the components to be maintained, whilst mitigating the components' disadvantages. In addition, it can facilitate the construction of large families at a greatly reduced computational cost. Combination families are considered through the construction of two new classes of sequences, modified Unified Complex Hadamard Transform (UCHT) sequences, and combination Oppermann sequences, respectively based on UCHT sequences and periodic Oppermann sequences. Numerical optimisation techniques are employed to demonstrate the favourable performance of sequences from these classes compared to conventional families. Second, IFW sequences are considered. In systems where approximate, but not perfect, synchronisation between different users can be maintained, IFW sequences can be employed to greatly reduce both interference between users and interference resulting from multipath spread of each user's signal. Large Area Synchronous (LAS) sequences are a class of sequences which both result from combination techniques and exhibit an IFW. LAS sequences are produced by combining Large Area (LA) sequences and LS sequences. They have been demonstrated to be applicable to multiple access communication systems, particularly through their use in LAS2000, which was proposed for third generation mobile telephony. Work to date has been restricted to only a very small range of examples of these families. In order to examine a wider range of LAS sequences, the construction and resulting properties of LA and LS families are considered. The conditions an LA family must satisfy are codified here, and algorithms which can be used to construct LA families with given parameters are presented. The construction of LS sequences is considered, and relationship between each of the parameters used in this construction and the properties of the final family is examined. Using this expanded understanding of both these sequence families, a far wider range of LAS families, potentially applicable to a wider range of applications, can be considered. Initially, the merits of proposed sequences are considered primarily through their correlation properties. Both maximum and mean squared correlation values are considered, depending on the context. In order to demonstrate their practical applicability, combination Oppermann, modified UCHT and LAS sequences are employed in a simulated communications system, and the resulting bit error rates are examined.