vii
TABLE OF CONTENTS
CHAPTER
1
TITLE
PAGE
DECLARATION
II
DEDICATION
III
ACKNOWLEDGEMENT
IV
ABSTRACT
V
ABSTRAK
VI
TABLE OF CONTENTS
VII
LIST OF TABLES
XI
LIST OF FIGURES
XII
LIST OF ABBREVIATIONS
XV
LIST OF ABBREVIATIONS
XVI
INTRODUCTION
1
1.1
Background of the study
1
1.2
Motivation
3
1.3
Problem formulation
4
1.4
Objectives of the Study
5
1.5
Scope of study
6
1.6
Methodology
6
1.6.1 Phase one: Background Recognition and
Problem Formulation
7
1.6.2 Phase 2: Prerequisites to Integrate Two
Systems via Modeling
7
1.6.3 Phase 3: Integrated System Simulation and
Evaluation
9
viii
2
1.6.4 Phase 4: System presentation in simulated
actual scenarios
9
1.7
Organization of the thesis
9
1.8
Summary
10
INTEGRATED SYSTEM BACKGROUND
RECOGNITION
12
2.1
Introduction
12
2.2
Visible Free Space Optic (VFSO)
13
2.2.1 History of VFSO
14
2.2.2 Indoor Data transmission utilizing Visible
Light
15
2.2.3 VFSO Transmitters
16
2.2.4 VFSO Receivers
20
2.2.5 VFSO Modulation
21
2.2.6 Standardization Efforts
28
2.2.7 Applications of VFSO
30
2.2.8 Challenging issues of VFSO
32
Broadband Powerline Communications (BPLC)
35
2.3.1 History of PLC
35
2.3.2 Applications of BPLC
36
2.3.3 Challenging issues of BPLC
38
2.3.4 Modulation scheme for BPLC
43
2.3.5 Standardization of PLC Systems
44
Integrated System of VFSO and BPLC
44
2.4.1 Existing Integrated Systems
45
2.4.2 Open issues related to integrated system
49
2.4.3 Specific applications of integrated system
49
Summary
50
2.3
2.4
2.5
3
SYSTEM MODELING OF BPLC & VFSO
51
3.1
Introduction
51
3.2
Channel Modeling Methods
51
3.2.1 BPLC Channel Modeling
52
ix
3.2.2 VFSO Channel Modeling
53
Noise Modeling Methods
57
3.3.1 BPLC Noise Modeling
58
3.3.2 VFSO Noise Model and SNR
61
Robust Modulation Scheme for Integrated
System
64
3.5
Practical White LED Modeling
65
3.6
Summary
66
3.3
3.4
4
5
INTEGRATED SYSTEM ARCHITECTURE,
ANALYTICAL ANALYSIS
67
4.1
Introduction
67
4.2
Integrated System Architecture Components
68
4.2.1 Generation of OFDM Signal at Transmitter
70
4.2.2 Transmission of OFDM signal through
Wired Powerline Channel
75
4.2.3 Optical Transmission and Intensity
Modulation (IM)
76
4.2.4 Direct Detection and Received SNR
81
4.3
Integrated System Bit Error Rate (BER)
83
4.4
White LED optical output power measurement
84
4.5
Summary
86
INTEGRATED SYSTEM SIMULATION AND
RESULTS DISCUSSION
87
5.1
Introduction
87
5.2
Powerline Multipath Channel Simulation
88
5.3
Powerline Channel Noise Simulation
89
5.4
BPLC System Simulation
91
5.4.1 Baseband BPLC OFDM System Subcarrier
Utilization
93
5.4.2 BPLC System Performance Analysis
without Coding
94
x
5.5
5.6
5.7
6
5.4.3 BPLC System Performance Analysis with
Coding
95
5.4.4 Achievable Data Rate of OFDM-BPLC
System
96
Integrating an Optical Interface to BPLC
97
5.5.1 Effects of White LED operation on OFDM
signal
98
5.5.2 White LED Radiometric Characteristics
100
5.5.3 BER performance of integrated system
104
5.5.4 Effects of subcarrier numbers on the BER
107
Integrating white LED arrays to BPLC
108
5.6.1 General Lighting Equipment Design
109
5.6.2 Room Lighting Design
112
Summary
116
CONCLUSION AND FUTURE WORK
118
6.1
Conclusion
118
6.2
Research Contributions
119
6.3
Future work
120
REFERENCES
121
xi
LIST OF TABLES
TABLE NO.
TITLE
PAGE
4.1
Measured received optical power
85
5.1
Simulation parameters of the BPLC channel. k=1,
a 0  0, a1  7.8  10 10
88
5.2
White LED Photometric characteristics (OSRAM, 2010)
102
5.3
Parameters chosen for optical receiver
105
5.4
Comparing the new system with other research studies
117
xii
LIST OF FIGURES
FIGURE NO
TITLE
PAGE
1.1
Research Flow Diagram
8
2.1
Literature Review Tree Map
13
2.2
The visible spectrum
14
2.3
White LED as Lighting and Communication device
15
2.4
Process of sending and receiving data via visible light
16
2.5
LED technological evolution
17
2.6
(a) Combined spectral curves for blue, Green and high
brightness red solid state semiconductor LEDs. (b)
Spectrum of a blue type “white” LED
18
2.7
Emission spectrum of a White LED (Luxeon, 2011)
19
2.8
Three types of white LEDs
19
2.9
Optical power detection using Photodetector
20
2.10
Typical driving circuit for modulating the optical output
from a (white) LED
21
Examples for subcarrier pulse position modulation in
context of VLC: SC-2PPM and SC-4PPM
23
2.12
Example for binary frequency shift keying in VLC
23
2.13
Basic OFDM realization
25
2.14
Spectra of OFDM signal
25
2.15
Duplication of guard time slot to build cyclic prefix (CP)
26
2.16
Block diagram of an OFDM system
27
2.17
DCO-OFDM and ACO-OFDM building blocks and LED
input-output/voltage-current relationship
28
2.11
xiii
2.18
Intersection of distance range curves to estimate current
location
30
2.19
Last-mile access
36
2.20
Structure of in-house access
37
2.21
General block diagram for BPLC systems
38
2.22
Multipath signal propagation in PLC channel echo model
40
2.23
Noise scenario in BPLC
41
2.24
Visual Concept of Integrated System
45
2.25
Main features of first proposed integrated system
46
3.1
Propagation model of (a) LOS link (b) Diffused link
54
3.2
Optical power spectra of: (a) Sunlight, (b) Halogen, (c)
Fluorescent lamps
62
3.3
Optical power spectra of WLED
62
4.1
Integrated system link architecture
68
4.2
Simulated Integrated System Main Components
69
4.3
Convolutional Encoder
70
4.4
Constellation point diagram of 16.QAM and 16.QPSK
72
4.5
OFDM symbol and IFFT bin assignment
73
4.6
OFDM Symbol
74
4.7
Optical Transmitter of VFSO
77
4.8
White LED Spectrum Emission (OSRAM, 2010)
79
4.9
Propagation parameters
79
4.10
Trans Impedance Amplifier
81
4.11
LED radiated power measurement setup diagram
84
4.12
Measured received optical power (left axes), optical output
power (right axes)
85
5.1
Frequency Response of Multipath Powerline Channel
89
5.2
Non-Gaussian noise model   0.01, K  10
90
5.3
Non-Gaussian noise model   0.5 , K  10
90
5.4
BPLC OFDM transmission system
92
5.5
Baseband-OFDM Subcarrier Utilization
93
5.6
BER comparison of three modulation schemes in BPLC
94
5.7
Comparison between simulation and theoretical BER of
64-QAM in BPLC-OFDM
95
xiv
5.8
BER performance of Coded BPLC-OFDM System
96
5.9
Integrating Optical Interface to BPLC
98
5.10
Time domain OFDM signal from Powerline Channel (
  0.5 )
99
5.11
White LED non-linear characteristics
99
5.12
White LED V-I curve from datasheet
101
5.13
White LED V-I characteristics modeled via MATLAB
interpolation technique. The dynamic range for this LED
is around 3.75-2.75=1 V P  P
101
The relation between the forward current through the LED
and the radiated power in watts
103
Current vs Luminous flux normalized to the luminous flux
at 350 mA (OSRAM datasheet)
103
5.16
BER of Integrated system vs OFDM signal power
106
5.17
BER performance for different numbers of modulated
subcarriers
107
5.18
General lighting equipment illuminance distribution
109
5.19
BER performance of integrated system of BPLC and GLE
design
111
5.20
Room dimensions for investigation
112
5.21
Ceiling model for investigation
113
5.22
Distribution of horizontal illumination
113
5.23
BER performance of integrated system of BPLC and GLE
design
115
5.14
5.15
xv
LIST OF ABBREVIATIONS
ACO-OFDM
AWG
AWGN
BER
BFSK
BPF
BPLC
CP
DC
DCO-OFDM
DD
DFT
DSP
FEC
FSK
GLE
HV
IFFT/FFT
IM
ISI
ITS
JEITA
LV
MCM
MIMO
M-QAM
MV
NRZ OOK
OFDM
PLC
OOK
PAPR
PDA
PPM
PSK
-
Asymmetrically clipped optical OFDM
Additive white Gaussian
Additive white Gaussian noise
Bit Error Rate
Binary frequency shift keying
Band pass filter
Broadband Powerline Communication
Cyclic prefix
Direct current
DC biased optical OFDM
Direct Detection
Discrete Fourier Transform
Digital signal processing
Forward error correction
Frequency shift keying
General lighting design
High voltage
(Inverse) Fast Fourier transform
Intensity Modulation
Intersymbol Interference
Intelligent transport system
Japan Electronics and Information Technology Industries Association
Low voltage
Multi-carrier modulation
Multi input, multi output
Multi-level quadrature amplitude modulation
Medium voltage
Non-Return to Zero On-Off Keying
Orthogonal Frequency Division Multiplexing
Powerline Communication
On-Off Keying
Peak-to-average power ratio
Personal digital assistance
Pulse position modulation
Phase shift keying
xvi
LIST OF ABBREVIATIONS
QAM
QPSK
RONJA
SC-BPSK
SC-PPM
SNR
TOV
VA
VFSO
VLC
VLCC
WLED
-
Quadrature amplitude modulation
Quadrature phase shift keying
Reasonable Object near Joint Access
Subcarrier Binary PSK
Subcarrier pulse position modulation
Signal to Noise Ratio
Turn On Voltage
Viterbi algorithm
Visible Free Space Optic
Visible Light Communication
Visible light communications consortium
White Light Emitting Diodes