الفهرس 
CHAPTER I : GENERAL INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The demand for broadband services has driven research on millimeter (mm)
wave band communications for wireless access network due to its spectrum
availability, and compact size of radio frequency devices.
Radio over fiber (ROF) technology and applications have been recently built
up over wide ranges. This technique has succeeded to engage both the fields of
radio and optical communication systems.
Thus, the present thesis focuses on the deep parametrical studies of
presenting and modeling of the transmission performance characteristics of the
ROF system that is modulated with multiple bit rates using different transmission
techniques such as Soliton, and maximum time division multiplexing. These
transmission techniques are employed through two ultra multiplexing techniques
and 4-24 links space division multiplexing plus multi channels dense wavelength
division multiplexing over optical window of special interest.
This thesis investigates the high performance of ROF communication
systems over traditional optical communication systems using different coding
formats over wide range of the affecting operating parameters. Moreover we
have analyzed the transmission bit rates and products per channel based standard
single mode fiber made of both silica-doped and plastic materials and by using
modified Shannon technique in addition to use different coding formats such as
Return to Zero code, and Non Return to Zero code for ultra long haul
transmission applications. The bit error rate has been taken into account for ROF
systems with comparing it with traditional optical fiber communication systems
as a proof for improvement of signal to noise ratio.
Moreover the thesis studies transporting the RF signal over few kilometers
with minimal loss using a vertical cavity surface emitting laser with a graded
index MMF polymer optical fibers to transport optical signals. As well as, a ROF
communication system within multimode polymer optical fibers has been
ABSTRACT
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developed for short transmission distances in coarse wavelength division
multiplexing technique using pulse code modulation schemes.
Also, A design of electrooptic modulators in the applications of ROF has
been studied and investigated. Integrated optic design is handled to build a tank
circuit to obtain the maximum output power. The modulated bandwidth is deeply
and parametrically studied over wide ranges of the affecting sets of parameters
via a specially designed software which processes the interaction of causes and
effects. The design parameters of the tank circuit have been processed over large
operating requirements. The output due to the nonlinear distortion has been also
analyzed, and its penalty is computed. Crystal modulator made of Potassium
Dihydrogen Phosphate (KDP) crystal is processed.
Finally, under thermal-irradiated operating conditions, the performance
characteristics of high speed laser diodes (based on Vertical Cavity Surface
Emitting Laser) in ROF systems are deeply and parametrically investigated. The
processed characteristics are: the harmonic response transfer function, the
resonance frequency, 3-dB bandwidth, and the rise time. These diodes affect the
transmitted bit-rate in high-speed advanced optical communication systems. The
effects of both ambient temperature (and consequently the inner temperature), the
injected current (power), and the dose of irradiation are deeply investigated. The
pulse rise time, and the resonance frequency as well as the 3-dB bandwidth are
the major criterions of the device speed. Nonlinear relations are correlated to
investigate the power-current and the voltage-current dependences of the devices.
Although a considerable amount of radiation effects studies on individual devices
exposed to a variety of radiation conditions is reported in literature, only little
information is available on the radiation tolerance at high total dose and under
neutron radiation.
Each topic is modeled, analyzed and deeply investigated parametrically over
wide ranges of its affecting causes.
Specially designed software programs are employed during the calculations
of the different effects of each topic.