"Convergence of Radio and Optical technologies for communication systems at frequencies higher than 60 GHz. "
Tuesday, September 22, 2015 at 9:30
This Ph.D. investigates the radio over fiber communication systems at mm-wave frequencies higher than 60 GHz. The thesis elaborates on three crucial issues in these systems including: phase noise measurement of unstable optically generated mm-wave signals, elimination of phase noise impact on performance of radio over fiber systems using non-coherent down conversion technique, and studying the amplitude noise impacts on performance of system based on these detectors.
In the first part of this work, a new digital phase noise measurement technique is presented which is able to extract the phase noise of any unstable mm-wave optically generated signal. This technique is able to measure the phase noise for a wide range of offset frequencies from close-in phase noise to far noise floor by adapting frequency resolution ofmeasurement and without considering small angle approximation.
In the second part, we present a radio over fiber system at mm-wave frequency based on non-coherent electrical frequency down conversion stage using an envelope detector which is robust against phase and frequency fluctuations of the optically generated carrier signal.
Finally, a theoretical and experimental study of amplitude noise impact on performance of radio over fiber systems based on non-coherent receivers is presented. In this study, a simulation technique based on theory is developed which is able to determine, among different optical and electrical noise, the one which has the dominant effect on EVM results. This simulation technique is based on observing the EVM evolution versus received optical power.