{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/112530"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/112530","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Comparison of quadrature detector and phase-locked loop demodulator performance with LEOSAT applications","abstract":"Continuous Phase Frequency Shift Keying (CPFSK) is a constant amplitude modulation of growing popularity in low earth orbit satellites (LEOSAT) because of its spectral efficiency. This thesis compares the error rate performance of CPFSK demodulation using quadrature detectors and phase-locked loops under varying carrier to noise ratios and simulated Doppler shifts, as might be expected for a low earth orbit satellite downlink. Experimental comparison between a quadrature detector and a phase-locked loop demodulator shows that phase-locked loop demodulators and quadrature detectors offer equivalent performance as demodulators at low carrier to noise ratios for narrowband FM/CPFSK systems. This contrasts with earlier work that shows that phase-locked loops can provide threshold extension for wideband FM systems.","abstract_html":"Continuous Phase Frequency Shift Keying (CPFSK) is a constant amplitude modulation of growing popularity in low earth orbit satellites (LEOSAT) because of its spectral efficiency. This thesis compares the error rate performance of CPFSK demodulation using quadrature detectors and phase-locked loops under varying carrier to noise ratios and simulated Doppler shifts, as might be expected for a low earth orbit satellite downlink. Experimental comparison between a quadrature detector and a phase-locked loop demodulator shows that phase-locked loop demodulators and quadrature detectors offer equivalent performance as demodulators at low carrier to noise ratios for narrowband FM/CPFSK systems. This contrasts with earlier work that shows that phase-locked loops can provide threshold extension for wideband FM systems.","abstract_has_math":false,"creators":["Lim, Stephen T."],"institution":"Virginia Polytechnic Institute and State University","degree_name":"M.S.","degree_level":"masters","degree_discipline":"Electrical Engineering","degree_department":"Electrical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1991,"date_issued":"1991","date_published":"1991","updated_at":"2026-07-22T22:18:50Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/112530","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Electrical Engineering"]},{"key":"dc:creator","label":"Author","values":["Lim, Stephen T."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2022-11-09T06:27:59Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-11-09T06:27:59Z"]},{"key":"dc:date.issued","label":"Date","values":["1991"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Polytechnic Institute and State University"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/112530"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Continuous Phase Frequency Shift Keying (CPFSK) is a constant amplitude modulation of growing popularity in low earth orbit satellites (LEOSAT) because of its spectral efficiency. This thesis compares the error rate performance of CPFSK demodulation using quadrature detectors and phase-locked loops under varying carrier to noise ratios and simulated Doppler shifts, as might be expected for a low earth orbit satellite downlink. Experimental comparison between a quadrature detector and a phase-locked loop demodulator shows that phase-locked loop demodulators and quadrature detectors offer equivalent performance as demodulators at low carrier to noise ratios for narrowband FM/CPFSK systems. This contrasts with earlier work that shows that phase-locked loops can provide threshold extension for wideband FM systems."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["M.S."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Comparison of quadrature detector and phase-locked loop demodulator performance with LEOSAT applications"]}]}],"canonical_facts":{"dc:contributor.department":["Electrical Engineering"],"dc:creator":["Lim, Stephen T."],"dc:date.accessioned":["2022-11-09T06:27:59Z"],"dc:date.available":["2022-11-09T06:27:59Z"],"dc:date.issued":["1991"],"dc:description.abstract":["Continuous Phase Frequency Shift Keying (CPFSK) is a constant amplitude modulation of growing popularity in low earth orbit satellites (LEOSAT) because of its spectral efficiency. 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