Measurement of Antenna Performance in Analog LMR Systems Using PL Tone Analysis

dc.contributor.authorKumar, Akshayen
dc.contributor.committeechairEllingson, Steven W.en
dc.contributor.committeememberClancy, Thomas Charles IIIen
dc.contributor.committeememberBeex, A. A. Louisen
dc.contributor.departmentElectrical and Computer Engineeringen
dc.description.abstractWe are interested in measuring the in situ antenna performance in analog land mobile radio (LMR) FM systems. The gain (efficiency and directivity) and self-impedance of an antenna sufficiently characterize its performance and a number of traditional methods exist to measure these quantities. However it is hard to do antenna gain measurements using these methods. Furthermore, it turns out that volumetric antenna gain measurements are not quite relevant for understanding in situ performance. In this thesis, we present a novel approach for directly measuring the in situ performance of antennas in analog LMR systems. The procedure involves receiving an FM signal simultaneously using the antenna under test (AUT) and a reference antenna. Both received signals are demodulated to audio using separate but identical receivers. Then a convenient method for characterizing the audio signal quality is to analyze the private line (PL) tone. The PL tone signal-to-noise ratio (SNR) is calculated by measuring the power of the tone relative to the sub-audio noise power. The PL tone SNR for both antenna systems is compared as it provides a ``bottom line'' evaluation of the antenna performance. The audio SNR can also be mapped to RF SNR using a theoretical method. From simulation and experimental studies, we conclude that the RF SNR estimated using this technique is within 0.5 dB of the actual value for RF SNR values between +3 and +36 dB. Finally, we demonstrate this procedure in actual in situ LMR antenna measurements.en
dc.description.degreeMaster of Scienceen
dc.publisherVirginia Techen
dc.rightsIn Copyrighten
dc.subjectAntenna performanceen
dc.subjectin-situ measurementsen
dc.subjectLMR systemsen
dc.subjectRF SNRen
dc.subjectPublic Safety Radioen
dc.titleMeasurement of Antenna Performance in Analog LMR Systems Using PL Tone Analysisen
dc.typeThesisen and Computer Engineeringen Polytechnic Institute and State Universityen of Scienceen
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