vii
TABLE OF CONTENT
CHAPTER
1
2
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xi
LIST OF FIGURES
xii
LIST OF ABBREVIATIONS
xv
LIST OF SYMBOLS
xviii
LIST OF APPENDICES
xxii
INTRODUCTION
1
1.1
Background
1
1.2
Problem Statement
3
1.3
Objectives of the Research
4
1.4
Scope of the Research
5
1.5
Research Contributions
5
1.6
Significance of the Research
7
1.7
Organization
7
LITERATURE REVIEW
9
2.1
Introduction
9
2.2
Ultra Wideband Radio
10
2.2.1 UWB Challenges
12
viii
2.3
2.4
2.5
3
15
Multicarrier Modulation
18
2.3.1 Wavelet Packet Based MCM
21
Cognitive Radio
26
2.4.1 Spectrum Sensing Methods
29
2.4.2 Cognitive Radio Links
30
2.4.3 Channel State Information
34
2.4.4 Interference Mitigation
38
Power Allocation and Channel Estimation
40
2.5.1
41
Power Allocation
2.5.2 Channel Estimation
43
2.6
Related Works
47
2.7
Summary
49
DESIGN OF WAVELET COGNITIVE UWB SYSTEM
51
3.1
Introduction
51
3.2
Proposed Wavelet Cognitive UWB System
52
3.2.1 WPMCM
55
3.2.2 Wavelet Spectrum Sensing
56
3.2.3 Spectrum and Power Allocation
58
Network Model
59
3.3.1 Wavelet Cognitive UWB Transceiver
61
3.3.2 Channel Model
63
3.4
Initial investigation of Multiband OFDM UWB
66
3.5
Summary
69
3.3
4
2.2.2 Multiband OFDM UWB
DEVELOPMENT OF WAVELET PACKET
70
MULTICARRIER MODULATION
4.1
Introduction
70
4.2
The Structure of WPMCM
71
4.3
Simulation and Discussion
77
4.4
Summary
84
ix
5
DEVELOPMENT OF WAVELET
85
SPECTRUM SENSING
6
5.1
Introduction
85
5.2
Functional Operation of Wavelet Spectrum Sensing
86
5.3
Decision Rule
87
5.4
Energy Detector
89
5.5
Thresholding Algorithm
91
5.5.1 FCME Algorithm
92
5.5.2 Double Thresholding
93
5.5.3 E-FCME Algorithm
94
5.6
Simulation and Discussion
96
5.7
Summary
DEVELOPMENT OF SPECTRUM AND
108
109
POWER ALLOCATION
7
6.1
Introduction
109
6.2
Spectrum and Power Allocation
110
6.3
Spectrum Identification
111
6.4
Channel Estimation
111
6.4.1 Signal Model
112
6.4.2 Virtual Pilots
113
6.5
Power Determination
115
6.6
Spectrum Shaping
116
6.7
Simulation and Discussion
117
6.8
Summary
127
CONLUSIONS AND FUTURE WORKS
128
7.1
Introduction
128
7.2
Future Works
131
REFERENCES
Appendix A-C
134
145-176
x
LIST OF TABLES
TABLE NO.
TITLE
PAGE
2.1
UWB data rates versus range
11
2.2
Frequency assignments for IEEE 802.11a WLAN
13
2.3
Parameters of IEEE 802.15.3a proposal
17
2.4
Averaged normalized power of interference for MCM
25
3.1
Parameters of multiband WPMCM UWB
61
3.2
Channel parameters for S-V model
65
4.1
Wavelet family characteristics
76
4.2
Results of Figure 4.9
80
5.1
Results of Figure 5.10
100
6.1
SNR Comparison
121
xi
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
2.1
Transmission coverage range vs. data rate
10
2.2
WPAN Applications of UWB
11
2.3
UWB spectral mask for indoor communication systems
12
2.4
NBI occurrences within UWB spectrum
13
2.5
Multiband UWB bandwidth division
15
2.6
TFC code for MB-OFDM
16
2.7
Existing architecture of MB-OFDM UWB
18
2.8
Four levels packet tree with nodes
22
2.9
MATLAB simulation of wavelet packet
2.10
Wavelet packet tree and its plane
24
2.11
Comparison of 3 systems in phase space
25
2.12
PSD of OFDM and wavelet based MCM
26
2.13
Cognitive radio phases
28
2.14
Arrangement of the primary and cognitive receivers
31
2.15
Block diagram of multiuser AMC
33
2.16
Mitola cognition process
35
2.17
A paradigm of a quantized CSI feedback
35
2.18
CSI Feedback Link Model
36
2.19
Channel state estimation and feedback model
37
2.20
Adaptive deactivation of subcarriers
38
2.21
Multiband approach
39
2.22
Iterative partitioned water-filling
42
2.23
Various pilot symbol aided arrangements
45
2.24
Virtual Pilot for cognitive radio
46
3.1
UWB system architecture
53
3.2
The flowchart of wavelet cognitive UWB system
54
22,23
xii
3.3
Proposed WPMCM block diagram
56
3.4
The simplified block diagram of the proposed
57
wavelet spectrum sensing
3.5
Proposed spectrum and power allocation block diagram
59
3.6
The cognitive and primary transmission scenario
60
3.7
Multiband wavelet cognitive UWB Transceiver
63
3.8
Different UWB channel impulse responses
66
3.9
Simulated multiband OFDM UWB
67
3.10
Multiband UWB signal
68
3.11
IEEE 802.15.3a UWB channel model parameters
68
4.1
The simplified block diagram of the proposed WPMCM
71
4.2
Block diagram of WPMCM
4.3
A two level splitting of the frequency domain
73
4.4
Complementary components of IWPT and WPT blocks
75
4.5
Input and output lines of IWPT in WPMCM module
77
4.6
Simulated UWB transceiver
78
4.7
BER comparison for different wavelet families
79
4.8
BER comparison between 4QAM, 16QAM, and 64QAM
80
4.9
BER comparison between OFDM and WPMCM
4.10
PSD of OFDM and WPMCM
83
5.1
Proposed wavelet spectrum sensing
87
5.2
Cognitive UWB radio links
88
5.3
The first two levels of WPT decomposition tree
90
5.4
The flowchart of FCME and E-FCME algorithm
5.5
Power spectral density of detected primary user’s signal
98
5.6
NMSE of bandwidth estimation for primary user
101
5.7
Probability comparison of detection for primary user
5.8
BER of FFT at AWGN channel
104
5.9
BER comparison of conventional and proposed
105
72,73
81,82
93,95
102,103
system under primary channel fading
5.10
BER comparison of conventional and
106,107
proposed system under UWB channel
6.1
Proposed spectrum and power allocation mechanism
110
6.2
Spectrum identification scheme
111
xiii
6.3
Channel estimation method
112
6.4
Proposed pilot pattern
114
6.5
Spectrum Shaping
117
6.6
Distribution of subcarriers
118
6.7
Power spectrum density of the primary user
119
6.8
Channel impulse response of CM2 in time domain
120
6.9
Channel impulse response of CM2 in frequency domain
120
6.10
Allocated power to the subcarriers in CM2 channel
122
for perfect and LS channel estimation
6.11
BER of perfect and LS channel estimation
123,124
6.12
BER comparison of proposed and conventional system 125,126
xiv
LIST OF ABBREVIATIONS
AIC
-
Active Interference Cancellation
AMC
-
Automatic Modulation Classifier
ANN
-
Artificial Neural Network
AWGN
-
Additive White Gaussian Noise
BER
-
Bit Error Rate
BPSK
-
Binary Phase Shift Keying
CE
-
Consumer Electronics
CFAR
-
Constant False Alarm Rate
CIR
Channel Impulse Response
CME
Consecutive Mean Excision
CP
-
Cyclic Prefix
CR
-
Cognitive Radio
CSCG
-
Circularly Symmetric and Complex Gaussian
CSD
-
Cyclostationary Detection
CSI
-
Channel State Information
CTS
-
Clear-To-Send
CU
-
Cognitive User
CWT
-
Continuous Wavelet Transform
DFT
-
Discrete Fourier Transform
DPC
-
Dirty Paper Coding
DS
-
Direct Sequence
DWT
-
Discrete Wavelet Transform
ED
-
Energy Detection
E-FCME
-
Enhanced Forward Consecutive Mean Excision
EM
-
Expectation Maximization
FC
-
Fusion Centre
FCC
-
Federal Communications Commission
xv
FCME
-
Forward Consecutive Mean Excision
FFT
-
Fast Fourier Transform
FIR
Finite Impulse Response
GI
Guard Interval
GPS
-
GSM
Global Positioning System
Global System for Mobile communication
ICI
-
Inter Carrier Interference
IFFT
-
Inverse Fast Fourier Transform
INR
-
Interference to Noise Ratio
ICI
-
Inter Carrier Interference
IR
Impulse Radio
ISI
-
Inter Symbol Interference
IWPT
-
Inverse Wavelet Packet Transform
LDPC
Low-Density Parity-Check
LRT
-
Likelihood Ratio Test
LS
-
Least Squares
MB
-
Multiband
MCM
-
Multicarrier Modulation
MCS
-
Modulation and Coding Scheme
MF
-
Match Filtering
MIMO
-
Multiple Input-Multiple Output
ML
-
Expectation Maximization
MMSE
-
Minimum Mean Squared Error
MRC
-
Maximum Ratio Combining
MSE
-
Mean Squared Error
NBI
-
Narrowband Interference
NMSE
-
Normalized Mean Square Error
OFDM
-
Frequency Division Multiplexing
PACE
-
Pilot Aided Channel Estimation
PAPR
-
Peaks to Average Power Ratio
PBI
-
Partial Band Interference
PDF
-
Probability Distribution Function
PLC
-
Power Line Communication
xvi
PSD
-
Power Spectral Density
PU
-
Primary User
QAM
-
Quadrature Amplitude Modulation
QMF
-
Quadrature Mirror Filter pair
QPSK
-
Quadrature Phase Shift Keying
RMT
Random Matrix Theory
RMS
Root Mean Square
RTS
-
Request-To-Send
SDR
-
Software Defined Radio
SFH
-
Slow Frequency Hopping
SINR
-
Signal to Interference and Noise Ratio
SNR
-
Signal to Noise Ratio
S-V model
Saleh-Valensuela model
TFC
-
Time Frequency Code
UWB
-
Ultra Wideband
V-BLAST
-
Vertical Bell Laboratories Layered Space Time
WBAN
Wireless Body Area Network
WLAN
-
Wireless Local Area Network
WPAN
-
Wireless Personal Area Networks
WPMCM
-
Wavelet Packet Based Multicarrier Modulation
WPT
-
Wavelet Packet Transform
WSN
-
Wireless Sensor Network
ZP
-
Zero Padding
xvii
LIST OF SYMBOLS
,
,
{
}
,
,
ℎ
ℎ
,
(. )
,
-
Assigned power for -th subcarrier
-
AWGN at
-
BER in the -th subcarrier
-
Bit number of the -th subcarrier
-
Channel gain
-
Channel impulse response
-
Channel impulse response for -th subcarrier
-
Coefficient of the gain for multipath cases
-
Cognitive base station
-
Cognitive receiver
-
Cognitive transmitter
-
Cognitive user’s transmitted signal
-
Complex Gaussian noise at cognitive receiver
-
Complex Gaussian noise at primary receiver
-
Delay of the
-th subcarrier data and -th symbol
-th cluster for the
-th channel
realization
-
Delay of the -th multipath component within the -th
cluster for the -th channel realization
-
Desired probability of false alarm at lower
-
Desired probability of false alarm at upper threshold
-
Dilatation decomposition filter
-
Dilatation reconstruction filter
-
Dirac delta function
-
Estimated bandwidth
-
Estimated channel impulse response at
data and -th symbol
-th subcarrier
xviii
-
FCME parameter
-
FFT/IFFT period
-
Guard interval duration
-
Guard time
-
Input data stream
-
Lagrange factor
-
lower frequency measured at -10
below the peak
emission point
,
,
(
(
Pd
Pfa
,
, )
, )
-
Lower threshold
-
Modulated waveform matrix
-
Noise
-
Number of data subcarriers
-
Number of pilot subcarriers
-
Number of wavelet packet levels
-
OFDM symbol duration
-
Orthogonal waveform coefficient
-
Orthogonal waveform for scaling coefficient
-
Orthogonal waveforms
-
Packet interval in frequency domain
-
Packet interval in time domain
-
Parallel symbols
-
Power constraint
-
Power of the received signal
-
Primary base station
-
Primary receiver
-
Primary transmitter
-
Primary user’s transmitted signal
-
Probability of detection
Probability of false alarm
Radius of the cognitive user coverage
-
Radius of the primary user coverage
-
Received interference signal at
-
Received signal
-th subcarrier data
xix
,
ℎ
,
ℎ
ΔF
( )
,
-
Received signal at
-th subcarrier data and
symbol
-
Sampling frequency
-
Scaling coefficient
-
Scaling decomposition filter
-
Scaling reconstruction filter
-
Signals at cognitive receiver
-
Signals at primary receiver
-
Subcarrier frequency spacing
-
Test statistic
-
The number of correctly detected subcarriers in c-th
cluster
-
,
The number of falsely detected subcarriers in c-th
cluster
,
-
Threshold value
-
Total bit number
-
Total number of subcarriers (FFT size)
-
Total of subcarriers used
-
Transmitted signal
-
Transmitted signal at
-th subcarrier data and
Upper frequency measured at -10
emission point
,
-th
symbol
-
,
-th
-
Upper threshold
-
Variance
-
Wavelet coefficient
-
wavelet packet in the position of ( , )
below the peak
xx
LIST OF APPENDICES
APPENDIX
TITLE
PAGE
A.1
CME algorithms
145
A.2
Backward CME
146
A.3
Forward CME (FCME)
146
B.1
Wavelet Packet Filter Design
148
B.2
Modified Remez Exchange Algorithm
150
C.1
MATLAB Codes
153