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dc.contributor.advisorO'Keefe, Kyle
dc.contributor.authorMozaffari, Mohammad
dc.date.accessioned2014-12-03T20:46:55Z
dc.date.available2015-02-23T08:00:30Z
dc.date.issued2014-12-03
dc.date.submitted2014en
dc.identifier.citationMozaffari, M. (2014). Weak GPS Signal Acquisition Using Antenna Diversity (Unpublished master's thesis). University of Calgary, Calgary, AB. doi:10.11575/PRISM/28677en_US
dc.identifier.urihttp://hdl.handle.net/11023/1945
dc.description.abstractGNSS Acquisition in fading and attenuated environments is challenging. In these situations, additional processing gain is required. A common method is to extend the coherent integration time. However, in weak signal situations, using only long coherent integration is limited by navigation data bit transitions and receiver oscillator instability. Using non-coherent and differentially coherent integration mitigates the bit transition problem but has lower processing gain as compared to coherent integration. Coherent, non-coherent and differentially coherent combining methods are not effective in dense multipath fading situations where the carrier-to-noise ratio (C/N0) varies significantly. Spatial antenna diversity provides additional processing gain to overcome multipath fading since multiple antennas detect signal components from independent fading channels. This thesis evaluates equal gain combining of two independent antennas in a standalone acquisition process. Traditionally acquisition has been evaluated at the cell level, which considers only a single cell, but in this thesis acquisition is assessed at the system level, where the complete acquisition process including the entire search space is examined. Receiver Operating Characteristic (ROC) curves in both cell and system levels are presented and compared both theoretically and using real data. Overall detection probability, probability of false alarm and acquisition time are investigated in terms of the mean and variance values. Optimal values for the integration time as well as combination of coherent and non-coherent integration that minimizes the mean acquisition time are obtained. The theoretical analysis is compared with Monte Carlo simulations and real GPS data results. Compared to a single antenna, smoother signal-to-noise ratio (SNR) values which show the fading mitigation were observed by applying diversity combining. Experimental results demonstrate the improvement of detection probability, enhanced immunity against false alarms, and significant reduction of the mean and variance of acquisition time in dense multipath environments.en_US
dc.language.isoeng
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectEngineering--Electronics and Electrical
dc.subject.classificationAcquisitionen_US
dc.subject.classificationWeak signalsen_US
dc.subject.classificationAcquisition timeen_US
dc.subject.classificationDiversityen_US
dc.titleWeak GPS Signal Acquisition Using Antenna Diversity
dc.typemaster thesis
dc.publisher.facultyGraduate Studies
dc.publisher.institutionUniversity of Calgaryen
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/28677
thesis.degree.nameMaster of Science
thesis.degree.nameMS
thesis.degree.nameMSc
thesis.degree.disciplineGeomatics Engineering
thesis.degree.grantorUniversity of Calgary
atmire.migration.oldid2775
dc.publisher.placeCalgaryen
ucalgary.item.requestcopytrue


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University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.