有線光通信網(wǎng)絡(luò)是一個(gè)非常依賴(lài)大氣環(huán)境的系統(tǒng),其光學(xué)特性和兩個(gè)收發(fā)器節(jié)點(diǎn)的環(huán)境干擾都是直接影響通信性能的重要因素。在這種情況下,信號(hào)的功率損耗與大氣中存在的粒子有著密切的關(guān)系,這些粒子會(huì)進(jìn)一步降低通信質(zhì)量。本文主要研究無(wú)線環(huán)境下多通道光網(wǎng)路的行為,以及在不同大氣氣象條件下,光束與粒子的相互作用。本研究主要對(duì)傳統(tǒng)光通信網(wǎng)路中常用的多波長(zhǎng)、信號(hào)功率及光學(xué)特性進(jìn)行分析,通過(guò)對(duì)工作波長(zhǎng)和光學(xué)參數(shù)的分析估計(jì)出不同氣候下環(huán)境的各種不穩(wěn)定特性的最佳光束對(duì)光學(xué)特性的影響。然后,分析了多通道技術(shù)在不同氣候等級(jí)下的衰減效應(yīng),并利用多種大氣模式估計(jì)了環(huán)境引起的不穩(wěn)定現(xiàn)象;并詳細(xì)分析了霧天對(duì)光信號(hào)的影響,并在此多通道技術(shù)下研究了光放大器的性能,將單個(gè)光源被分割,在多個(gè)通道上復(fù)制光信號(hào),從而確保每一個(gè)損壞位都有可能接收到光信號(hào),同時(shí)也降低了衰減效果。此外,本文還分析了光束發(fā)散和收發(fā)器孔徑隨誤碼率的變化,并將提出的光通信網(wǎng)絡(luò)方案與傳統(tǒng)方案進(jìn)行了比較,并從接收功率、信噪比、鏈路余量和質(zhì)量因子等方面對(duì)結(jié)果進(jìn)行了描述。

【文章頁(yè)數(shù)】：106 頁(yè)

【學(xué)位級(jí)別】：碩士

【文章目錄】：
ACKNOWLEDGEMENT
abstract
摘要
List of Abbreviation
List of Symbols
Chapter #1 :Introduction
    1.1 Overview
    1.2 Overview of Transceivers in OWCN Communication
    1.3 Background
    1.4 Modern Period of OWCN
    1.5 Challenges in OWCN
    1.6 Features of OWCN
    1.7 Uses of Optical Wireless Communication Network
        1.7.1 Military communication
        1.7.2 Satellite and deep-space communication
    1.8 System Overview
        1.8.1 Source and Detectors in Optics
        1.8.2 Multiple Pulse Position Modulator
        1.8.3 The Modulator and Transmitter
            1.8.3.1 Light Emitting Diode(LED)
            1.8.3.2 Laser
            1.8.3.3 Laser Diode
        1.8.4 The Channel
            1.8.4.1 Turbulence
            1.8.4.2 Aerosol Scattering
        1.8.5 The Mechanism at Receiver End
            1.8.5.1 PIN Photodiode
            1.8.5.2 Avalanche Photodiode
    1.9 Applications of OWCN
    1.10 Electromagnetic Spectrum and Light
    1.11 Wavelengths
        1.11.1 850nm
        1.11.2 1330nm
        1.11.3 1550nm
    1.12 Turbulences in Atmosphere
        1.12.1 Fog
        1.12.2 Snow
        1.12.3 Smoke
        1.12.4 Rain
        1.12.5 Dust
        1.12.6 Absorption
        1.12.7 Scattering
            1.12.7.1 Rayleigh Scattering
            1.12.7.2 Mie(Aerosol)Scattering
        1.12.8 Scintillation
    1.13 Research Objective
    1.14 Original Contributions of This Thesis
Chapter #2:Literature Review
    2.1 The Effects of Atmospheric Conditions
    2.2 Measurement of BER
    2.3 BER Effects of Internal and External Noise
    2.4 Flat-top Multi-beam FSO
    2.5 Comparison of850nm and1550nm in Controlled Condition
    2.6 Scattering Effect on Terrestrial FSO
    2.7 Affecting of Rain Attenuation on FSO Link
    2.8 WDM-FSO Considering Atmospheric Turbulence
    2.9 WDM-MIMO Working Model
    2.10 Attenuation Modelling of Fog and Smoke
    2.11 Link Budget Optimization of FSO
    2.12 Optimization of FSO Using Multi-Beam
    2.13 Performance Improvement by Different Transmitter and Receiver Aperture
    2.14 Sensitivity of Laser Attenuation
    2.15 Multi-Channel Communication in FSO
    2.16 Channer Models in FSO
    2.17 Optical Link Performance at530nm
    2.18 Simulation of Single and Multiple Transceivers
    2.19 Beam Divergence and BER
    2.20 Improving the performance of BER
    2.21 Atmospheric Losses in850nm&1550nm
    2.22 Optical wavelengths Comparison
    2.23 Application and Challenges of FSO
    2.24 Tropical Weather using Multi Beams
    2.25 Smoke Attenuation in in Controlled Condition
    2.26 Modulator for Ro FSO
    2.27 Rain Effects in Libyan Climate
    2.28 Scintillation Effect on Free Space Optics
    2.29 High Bandwidth in Fog and Snow
    2.30 Optical Beam Scattering and Wandering
    2.31 Propagation of Optical and Infrared Waves
    2.32 Effects of Dust Strome on FSO
Chapter #3:Research Methodology
    3.1 Optical Source and Detector
        3.1.1 The Transmitter
        3.1.2 The Atmosphere
        3.1.3 Optical Receiver
    3.2 Al NABOULSI Attenuation Measured Model
    3.3 Beer Lambert Law for Atmospheric Attenuation
    3.4 Kim Kruse Model for Measurement of Optical Attenuation
    3.5 Carbonneau’s Model for Rain Attenuation
    3.6 Dust Attenuation Model
    3.7 Snow Attenuation Model
    3.8 Smoke Attenuation Model
    3.9 Geometrical Loss
    3.10 Signal to Noise Ratio and Bit Error Rate
    3.11:Received Power of Rainfall
    3.12 Received Power of Fog
    3.13 Optical Link Margin
    3.14 Design and Simulation of Conventional SISO Link
    3.15 Design and Simulation of Proposed Multi-Channel Technique
Chapter #4:Results and Discussion
    4.1 Atmospheric Attenuation Models
        4.1.1 Dust Attenuation Model
        4.1.2 Fog Attenuation Model
        4.1.3 Smoke Attenuation Model
        4.1.4 Snow Attenuation Model
    4.2 Analysis of Bit Error Rate and Signal to Noise Ratio
    4.3 Wavelength comparison Analysis
    4.4 Rainfall Rate Comparison
    4.5 Geometric Loss Analysis
    4.6 Received Power Analysis
    4.7 Link Margin Analysis
    4.8 Q-Factor Analysis
    4.9 Analysis of SISO and Multi-channel Model
Conclusion
References



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