viii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
DECLARATION
ii
DEDICATION
iv
ACKNOWLEDGEMENTS
v
ABSTRACT
vi
ABSTRAK
vii
TABLE OF CONTENTS
viii
LIST OF TABLES
xi
LIST OF FIGURES
xii
LIST OF ABBREVIATIONS
xv
LIST OF SYMBOLS
xvii
LIST OF APPENDIX
xviii
INTRODUCTION
1.1
Historical perspective
1
1.2
Problem Statement
3
1.3
Objective
4
1.4
Scope of the Work
1.5
1.6
Methodology
Thesis Outline
RADIO OVER FIBER COMMUNICATION
SYSTEM
2.1 Radio over Fiber
5
6
7
9
ix
2.1.1 Introduction to RoF Optical Links
10
2.1.2. Basic Radio Signal Generation and
11
Transportation Methods
2.1.3
2.2
3
RoF Link Configurations
Optical Modulator
15
2.2.1 Mach Zehnder modulator.
15
2.2.2 Principle of MZ modulator
16
2.2.3 Electrooptic Phase modulator
18
2.3
Light Source
19
2.4
Fiber link
20
2.4.1
Step-Index Fiber
20
2.4.2
Graded-Index Fiber
23
2.5
Optical amplifier
24
2.6
Literature Review
26
THE SCM/WDM FOR ROF COMMUNICATION
3.1. Introduction
29
3.2. Subcarrier Multiplexing (SCM)
30
3.3. Analog SCM
31
3.4. Digital SCM
32
3.5. Basic WDM Scheme
34
3.5.1 Multiplexer and Demultiplexer
3.6. The SCM/WDM System for Radio over Fiber
4
13
35
37
THE SCM/WDM SYSTEM MODEL
4.1. Introduction
39
4.2. The SCM/WDM System Model
40
4.3. The Transmitter Model
42
4.4. The Transmission Link Model
46
4.5. The Receiver Model
50
4.6. Conclusion
53
x
5
SIMULATION RESULT AND PERFORMANCE
ANALYSIS
5.1. Introduction
54
5.2. The Transmitter Simulation Results
56
5.3. The Transmission Link Simulation Results
60
5.4. The Receiver Simulation Results
63
5.5. The Eye Diagram
65
5.6. Performance Analysis of The SCM/WDM for RoF
System
68
5.7. Analysis of The Total Power to The EDFA Length
68
5.8. The Performance of WDM Mux/Demux
70
5.9. The Carrier-to-Noise Ratio (CNR) Performance
71
5.10. Analysis on The Number of Channels
72
5.11. The Performance Analysis of Signal-to-Noise-Ratio
(SNR)
73
5.12. Bit-Error Rate Performance
74
5.13. Analysis of Nonlinearity Due to Optical Power
75
Level
6
5.14. Analysis of RF Bandwidth Spectrum
78
5.15. Conclusion
79
CONCLUSIONS AND RECOMMENDATION
6.1
Discussions
80
6.2
Conclusions
81
6.3
Future Recommendations
82
REFERENCES
84
Appendix A
93
xi
LIST OF TABLES
TABLE NO.
TITLE
PAGE
2.1
Typical Step-Index Fiber characteristic
22
4.1
Global simulation setup
43
4.2
Subcarrier frequency allocation
44
4.3
Simulation setup for EDFA
47
4.4
Simulation setup for Single Mode Fiber
49
4.5
Simulation setup for APD Photo detector
51
5.1
WDM Mux Results
61
5.2
The WDM Demux Results
62
5.3
A basic simulation setup for SCM/WDM-RoF with
70
EDFA
5.4
Basic simulation setup for nonlinearity of power levels
76
xii
LIST OF FIGURES
TITLE
PAGE
FIGURE NO.
1.1
The methodology flow chart
6
2.1
Intensity-modulation direct-detection (IMDD) analog
12
optical link
2.2
Representative RoF link configurations.
14
(a) EOM, RF modulated signal.
(b) EOM, IF modulated signal,
(c) EOM, baseband modulated signal.
(d) Direct modulation.
2.3
Basic configuration of Optical modulator
15
2.4
Basic architecture of using Phase Modulator
18
2.5
Typical Layout of a Bidirectional Analog Optical Link
20
Using Direct Modulation of Laser Diodes
2.6
Step-Index Fiber
21
(a) Refractive index profile
(b) End view.
(c) Cross-sectional side view
2.7
Graded-Index Fiber
23
(a) Refractive Index profile
(b) End view
(c) Cross-sectional side view
2.8
Schematic diagram of a simple Doped Fiber Amplifier
24
xiii
2.9
(a) Transmitted data at STM-4 rate
27
(b) Received data at STM-1 rate for 70 km
27
(c) The eye pattern generated by SCM at 622 Mbps at
28
70 km.
3.1
Basic configuration of RF modulation
30
3.2
Schematic of a WDM fiber Link
34
3.3
Multiplexing and Demultiplexing in a Unidirectional
36
System
3.4
Multiplexing and Demultiplexing in a Bidirectional
36
System
3.5
The SCM/WDM Link Configuration
37
4.1
Model of eight channels the SCM/WDM-ROF system.
41
4.2
Transmitter for electrical (RF) domain
42
4.3
Transmitter for optical domain
45
4.4
Transmission link
47
4.5
The receiver for optical domain
51
4.6
The receiver for electrical domain
52
5.1
Signal wave modulated by PSK
56
5.2
(a) RF spectrum for data signal on first channel
57
(3.6GHz).
(b) RF spectrum for data signal on eleventh channel
(23.4 GHz).
(c) RF spectrum for data signal on fourth channel
(10.8 GHz).
(d) RF spectrum for data signal on tenth channel
(16.2 GHz).
5.3
RF spectrum for adding eight channels of SCM-1 and
58
SCM-2
5.4
Amplified composite RF signals
58
5.5 (a) & (b)
Spectrum of the signal after Mach Zehnder Modulator
59
xiv
5.6 (a) & (b)
WDM Mux Signal Spectrum output
60
5.7
WDM Demux Spectrum Signals
61
5.8
Optical Spectrum After EDFA
62
5.9
Optical spectrum and Optical Power after propagated
63
150 km in fiber
5.10
RF spectrum detected by photo detector
63
5.11
Amplified received RF spectrum
64
5.12
Demodulation sample of the RF spectrum for channel
64
5.13
Received electrical signal wave
65
5.14
Eye Diagram for the channel 1 of SCM-1 Channel
66
5.15
Eye Diagram for the channel 2 of SCM-1 Channel
66
5.16
Eye Diagram for the channel 3 of SCM-1 Channel
66
5.17
Eye Diagram for the channel 8 of SCM-1 Channel
67
5.18
Eye Diagram for the channel 2 of SCM-2 Channel
67
5.19
Eye Diagram for the channel 8 of SCM-2 Channel
67
5.20
(a): The performance of the total power to the Fiber
69
Length with and without EDFA in 100 km
(b) The performance of Total power to the fiber length
with and without EDFA in 150 km
5.21
The OSNR performance of the WDM Mux /Demux
71
5.22
CNR for SCM-1 Channels with power 1 mW
71
5.23
CNR performance for SCM-2 Channel with power
72
5mW
5.24
5.25
The performance of RF carrier signal for SCM-1 &
SCM-2
(a) SNR performance of SCM at 100 km
73
74
(b) SNR performance of SCM at 150 km
5.26 (a) & (b)
The performance of BER for SCM-1 and SCM 2
75
5.27
Nonlinearity Performance of the Total Power versus
76
Fiber Length
5.28 (a), (b), (c)
The performance of Total Power (0 dBm) to the Fiber
77
Length
5.29:
The performance of RF bandwidth Spectrum are
expanded to 60 GHz
78
xv
LIST OF ABBREVIATIONS
XPM
-
Cross Phase Modulation
SPM
-
Simple-Phase Modulation
LD
-
Laser Diode
PD
-
Photo Detector
LED
-
Light Emitting Diode
APD
-
Avalanche Photodiode
SCM
-
Sub-carrier Multiplexing
WDM
-
Wavelength Division Multiplexing
SNR
-
Signal to Noise Ratio
CNR
-
Carrier to Noise Ratio
DWDM
-
Dense Wavelength Division Multiplexing
BW
-
Bandwidth
OSSB
-
Optical Single Side Band
ODSB
-
Optical Double Side Band
OTDM
-
Optical time Division Multiplexing
OCDM
-
Optical Code Division Multiplexing
EAM
-
Electro Absorption Modulator
SMF
-
Single Mode Fiber
MMF
-
Multi mode Fiber
GRIN
-
Graded Index
RF
-
Radio Frequency
MZM
-
Mach-Zehnder Modulator
CSNRZ
-
Carrier Suppressed Non return to Zero
EDFA
-
Erbium Doped Fiber Amplifier
xvi
RZ
-
Return to Zero
NRZ
-
Non return to Zero
PMD
-
Polarization Mode Dispersion
PRBS
-
Pseudo Random Bit Sequence
RoF
-
Radio over Fiber
CW
-
Continuous Wave
IMD
-
Inter modulation distortion
OFDM
-
Orthogonal Frequency Division Multiplexing
ASK
-
Amplitude Shift Keying
FSK
-
Frequency Shift Keying
PSK
-
Pahse Shift Keying
QAM
-
Quadrature Amplitude Modulation
BPSK
-
Binary Phase Shift Keying
QPSK
-
Quadrature Phase Shift Keying
OQPSK
-
Offset Quadrature Phase Shift Keying
OOK
-
On Off Keying
BER
-
Bit Error rate
MPSK
-
Minimum Phase Shift Keying
CATV
-
Cable television
TDM
-
Time division multiplexing
OCDMA
-
Optical Code Division Multiple Access
FTTx
-
Fiber To The Home, curb, etc.
MH
-
Mobile Home
SONET
-
Synchronous Optical Network
DFB
-
Distributed Feedback Laser
SDH
-
Synchronous Digital Hierarchy
MAN
-
Metropolitan Area Network
LAN
-
Local Area Network
BS
-
Base Station
MS
-
Mobile Station
CS
-
Central Station
xvii
LIST OF SYMBOLS
λ
-
Wavelength
h
-
Blank’s Constant
C
-
Velocity of Light
Eg
-
Energy Gap
fc
-
Cut-off frequency
η
-
Quantum Efficiency
ℜ
-
Responsivity
ip
-
Photocurrent
Po
-
Optical Power
q
-
Electron Charge
T
-
Temperature
K
-
Boltzmann Constant
B
-
Bandwidth
R
-
Nominally matched Resistance
Vth
-
The rms value for the thermal noise voltage
ΔP 2
-
Mean square amplitude of the noise fluctuations
α
-
Mie Scattering Coefficient
P(Z)
-
The laser Power at Z
P(I)
-
Output optical power
I
-
The current injected to the active region
V
-
Volume of the active region
Q
-
Photon Density
xviii
LIST OF APPENDIX
APPENDIX
A
TITLE
Accepted Paper: “The SCM/WDM
System Model for Radio over Fiber
Communication Link” RAFSS 2008 Ibnu
Sina Institute of UTM, 27 – 29 May 2008
PAGE
94