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Title: Modelling the transport of complex modulation in radio-over-fibre networks
Author: Sari, Saad
ISNI:       0000 0004 2669 9171
Awarding Body: UCL (University College London)
Current Institution: University College London (University of London)
Date of Award: 2008
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The proliferation of wireless LANs and other wireless devices coupled with increased demand for broadband services are putting pressure on wireless systems to increase capacity. This thesis is concerned with modelling Radio- over-Fibre (RoF) modulation techniques and investigating the performance of cost effective systems. The initial chapters outline optical communication techniques, benefits, applications, and limitations. The second part of the thesis is dedicated to the simulation of reported modulation techniques which are tolerance to optical fibre dispersion. Optical intensity modulation techniques of conventional Double Sideband (DSB), Single Sideband (SSB), and Double Sideband-Suppressed Carrier (DSB-SC) were considered in this work. Performance of the RoF modulation techniques were reported in terms of system linearity limitations and capability of transmitting complex signals. The last part of the thesis explores Orthogonal Frequency Division Multiplexing (OFDM) performance over fibre, considering dispersion tolerant modulation techniques, in terms of performance and limitations with various signal parameters. Comparative assessments of dispersion tolerant Radio-over-Fibre modulation techniques based on Intensity Modulation-Direct Detection IM-DD, with particular attention to the Double Sideband-Suppressed Carrier (DSB-SC) modulation have been reported in this work. It has been found that each of the examined techniques has a unique advantages as well as weak points related to the performance or the system cost. The main advantage of the OSSB+C technique is that it can eliminate the power variation over the entire range of the modulation frequency and fibre length. Moreover, it has been demonstrated that the Double Sideband-Suppressed Carrier (DSB-SC) modulation can shift the dispersion effect to a higher frequency-length products. Finally, we have explored, for the first time, the performance of the RF up-converted OFDM signal over the RoF optical links. OFDM modulation signals based on BPSK, QPSK, 16-QAM and 64-QAM Gray coded mappings have been applied, and the effects of OFDM modulation parameters on the achievable signal transmission over the RoF link were assessed.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available