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dc.contributor.authorSylvester, William R.en_US
dc.date.accessioned2014-03-14T21:43:00Z
dc.date.available2014-03-14T21:43:00Z
dc.date.issued1992en_US
dc.identifier.otheretd-08182009-040444en_US
dc.identifier.urihttp://hdl.handle.net/10919/44288
dc.description.abstractThis document describes the theory, design and implementation of a digital receiver designed for the ACTS propagation experiments. The Virginia Tech Satellite Communications Group is designing, constructing and distributing eight ACTS propagation terminals (APTs) under a contract with NASA. The terminals will measure the received signal power from the ACTS satellite beacons (20 GHz, 27.5 GHz) in various climates at different elevation angles. The resulting signal power measurement, radiometer and weather measurement data will be used to characterize atmospheric effects on signal propagation at Ka band. Each APT system will contain two identical, independent digital receivers; one 20 GHz channel and one 27.5 GHz channel. The algorithm implemented on each receiver utilizes the results of multiple fast Fourier transforms to reliably identify the carrier tone amidst neighboring modulation tones. The acquisition procedure, can reliably identify the carrier signal at signal-to-noise ratios down to 10 dB in a 20 Hz bandwidth (23 dBHz in a 1 Hz bandwidth, -26 dB relative to clear air conditions on the APT system) in 2 seconds. The receiver then uses a comb filter, two FIR filters and additional FFTs to produce power measurements accurate to 0.1 dB at signal-to-noise ratios down to 5 dB in a 20 Hz bandwidth (18 dBHz in a 1 Hz bandwidth, -31 dB relative to clear air conditions on the APT system) at 1 Hz and 20 Hz sampling rates. The algorithm also provides several supplemental functions including a software selectable detection bandwidth from 2 Hz to 50 Hz (1 Hz increments), spectrum analyzer type output for a 303.333 kHz bandwidth centered on the current carrier frequency and carrier frequency estimates accurate to ±O. 5 Hz.en_US
dc.format.mediumBTDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartLD5655.V855_1992.S977.pdfen_US
dc.relation.haspartLD5655.V855_1992.S977_drw01.pdfen_US
dc.subjectMicrowave receivers.en_US
dc.subject.lccLD5655.V855 1992.S977en_US
dc.titleTheory, design and implementation of a digital receiver for the Advanced Communications Technology Satellite (ACTS) beaconsen_US
dc.typeThesisen_US
dc.contributor.departmentElectrical Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineElectrical Engineeringen_US
dc.contributor.committeechairNunnally, Charles E.en_US
dc.contributor.committeememberBeex, A. A. (Louis)en_US
dc.contributor.committeememberPratt, Timothyen_US
dc.contributor.committeememberStutzman, Warren L.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08182009-040444/en_US
dc.date.sdate2009-08-18en_US
dc.date.rdate2009-08-18
dc.date.adate2009-08-18en_US


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