Loading...
- Type of Document: Ph.D. Dissertation
- Language: Farsi
- Document No: 39020 (05)
- University: Sharif University of Technology
- Department: Electrical Engineering
- Advisor(s): Salehi, Javad
- Abstract:
- In this thesis we examine and study the transmission of Ultra Wide Band (UWB) signals over single mode fiber in a radio over fiber system. We begin by developing mathematical model for the key optical components employed in radio over fiber systems. The authenticity of these models is verified with experimental results. Following the above models as well as experiment results, the transmission of UWB signals over optical fiber is investigated. The impact of limited operating bandwidth and nonlinearity of the electrical to optical transfer function on UWB signals is examined. Two types of UWB signals, namely, multi-band orthogonal frequency division multiplexing (MB-OFDM) and impulse radio ultra wide band (IR-UWB) are considered. Using the mathematical models of optical components we compare the above two UWB formats in terms of their sensitivity to the distortions existing in a radio over fiber link. The above discussion is focused on the downlink of UWB over fiber system. For the uplink, we consider a differential system whose receiver structure is simple to implement. For the receiver structure we consider both an electrical receiver and a novel optical receiver. The optical receiver introduced in this thesis, for the first time, is studied in the context of IR-UWB. This optical receiver can alleviate the IR-UWB receiver implementation challenges. It is similar to the optical receiver used for digital optically phase modulated DPSK (Differential Phase Shift Keying), however in this thesis we propose the receiver, for the first time, in optical transmission of UWB signals over fiber optic medium. We also study the conventional electrical differential receiver and compare its performance with that of the proposed optical receiver. The mathematical models for optical components such as laser diode and single mode fiber, along with the analytical expressions for the receivers’ error probability are used to evaluate the performance of the overall UWB over fiber system
- Keywords:
- Fiber Optics ; Mathematical Modeling ; Ultra Wide Band Channel ; Laser Diode ; Radio over Fibers (ROF)
- محتواي پايان نامه
- view