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New energy detector extensions with application in sound based surveillance systems

This thesis is dedicated to the development of new energy detectors employed
in the detection of unknown signals in the presence of non-Gaussian and
non-independent noise samples. To this end, an extensive study has been
conducted on di erent energy detection structures, and novel techniques
have been proposed which are capable of dealing with these problematic
situations.
The energy detector is proposed as an optimum solution to detect uncorrelated
Gaussian signals, or as a generalized likelihood ratio test to detect
entirely unknown signals. In both cases, the background noise must be
uncorrelated Gaussian. However, energy detectors degrade when the noise
does not ful ll these characteristics. Therefore, two extensions are proposed.
The rst is the extended energy detector, which deals with the problem
of non-Gaussian noise; and the second is the preprocessed extended energy
detector, used when the noise also possesses non-independent samples. A
generalization of the matched subspace lter is likewise proposed based on a
modi cation of the Rao test. In order to evaluate the expected improvement
of these extensions with respect to the classical energy detector, a signalto-
noise ratio enhancement factor is de ned and employed to illustrate the
improvement achieved in detection.
Furthermore, we demonstrate how the uncertainty introduced by the unknown
signal duration can decrease the performance of the energy detector.
In order to improve this behavior, a multiple energy detector, based on successive
subdivisions of the original observation interval, is presented. This
novel detection technique leads to a layered structure of energy detectors
whose observation vectors are matched to di erent intervals of signal duration.
The corresponding probabilities of false alarm and detection are derived
for a particular subdivision strategy, and the required procedures for their
general application to other possible cases are indicated. The experiments
reveal the advantages derived from utilizing this novel structure, making it
a worthwhile alternative to the single detector when a signi cant mismatch
is present between the original observation length and the actual duration
of the signal. / Moragues Escrivá, J. (2011). New energy detector extensions with application in sound based surveillance systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/11520 / Palancia

Identiferoai:union.ndltd.org:upv.es/oai:riunet.upv.es:10251/11520
Date12 September 2011
CreatorsMoragues Escrivá, Jorge
ContributorsVergara Domínguez, Luís, Gosálbez Castillo, Jorge, Universitat Politècnica de València. Departamento de Comunicaciones - Departament de Comunicacions
PublisherUniversitat Politècnica de València
Source SetsUniversitat Politècnica de València
LanguageEnglish
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion
SourceRiunet
Rightshttp://rightsstatements.org/vocab/InC/1.0/, info:eu-repo/semantics/openAccess

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