Comparison of quadrature detector and phase-locked loop demodulator performance with LEOSAT applications

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.

Name thesis:degree_name

M.S.

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Electrical Engineering

Department dc:contributor.department

Electrical Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1991

Author dc:creator

• Lim, Stephen T.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/112530

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/112530