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Title: Extended array manifolds
Author: Efstathopoulos, Georgios
ISNI:       0000 0004 2737 5590
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2008
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This thesis is concerned with the investigation of the extended array manifolds and their applications. Extended array manifolds are an extension of the spatial array manifold by incorporating additional channel parameters, such as the CDMA code, the lack of synchronisation, etc. Initially, the geometric properties of these manifolds are derived using differential geometry. Then the theoretical knowledge acquired by this investigation is used to estimate theoretical performance bounds for array systems, analyse the performance of channel estimation algorithms and finally design a novel algorithm for array calibration in a nonstationary signal environment. Firstly, the concept of the "extended" array manifolds is introduced. This generic model is shown to accommodate both existing and newly defined extensions of the widely employed in the literature spatial array manifold. The geometry of the extended array manifolds is studied and the theoretical results are then readily applied to estimate the geometric properties of various array manifolds. Furthermore, existing theoretical performance bounds for linear array systems are extended for array systems of arbitrary 3-dimensional geometry. The theoretical tools developed during the analysis of the extended array manifolds are used in order to compare the performance of various array systems employing antenna arrays of identical geometry, but operating in diverse signal environments. A special class of array manifolds, “hyperhelical” manifolds, is studied next. Their study is motivated by their unique properties, which greatly facilitate the computability of their geometric parameters. The issues of existence and uniqueness of hyperhelical manifolds is addressed and the various antenna geometries giving rise to hyperhelical array manifolds are identified. Finally, the problem of array uncertainties is tackled using a geometric approach. The effects of geometric and carrier uncertainties on channel estimation and subspace based, algorithms are investigated and modelled. Based on this modelling, an array calibration algorithm for a non-stationary signal environment is proposed.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available