vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xii
LIST OF FIGURES
xiv
LIST OF ABBREVIATIONS
xx
LIST OF SYMBOLS
xxi
LIST OF APPENDICES
xxiii
INTRODUCTION
1
1.1
Introduction
1
1.2
Problem Statement
3
1.3
Objective of The Research
4
1.4
Scope of The Research
5
1.5
Significant of Works
7
1.6
Thesis Outline
8
MIMO-OFDM WIRELESS COMMUNICATIONS
10
2.1
Introduction
10
2.2
Wireless Channel Impairments
11
2.3
MIMO Wireless Communication Systems
14
viii
2.3.1
Space-Time Diversity Approach
16
2.3.1.1 Space Time Block Codes
18
2.3.1.2 Space-Time Trellis Codes
22
Spatial Multiplexing Approach
25
2.3.2.1 VBLAST
27
2.3.2.2 DBLAST
29
2.3.2.3 Other BLAST Architectures
30
Application of MIMO Schemes on OFDM Systems
34
2.4.1
OFDM System
36
2.4.2
Application of Space Time Coding
38
2.4.3
Application of Spatial Multiplexing Schemes
42
2.3.2
2.4
2.5
Error Correcting Codes for MIMO-OFDM System
42
2.5.1 Convolutional Codes
43
2.5.2
Multidimensional Turbo Product Codes
45
2.5.2.1 Component Codes of TPC
48
2.5.2.2 Symbol by Symbol Soft Iterative TPC
Decoding
2.5.2.3 Pairwise Error Probability of TPC
2.6
2.8
3
52
Channel Estimation Strategy for MIMO-OFDM
System
2.7
49
54
Application of MIMO-OFDM System for Wireless
LAN
57
Summary
59
MULTIDIMENSIONAL TURBO PRODUCT CODES
63
3.1
Introduction
63
3.2
Dimensional Based Reading Order of MDTPC
Codeword
65
3.2.1 DBRO Algorithm
66
3.2.2
DBRO Codeword Generator for 2D MDTPC
71
3.2.3
DBRO Codeword Generator for 3D MDTPC
74
3.2.4
DBRO Codeword Generator for 4D MDTPC
81
3.2.5
DBRO Codeword Generator for 5D MDTPC
84
ix
3.3
3.4
3.5
4
Proposed Parallel Decoder for D Dimensional
MDTPC
86
3.3.1
89
Decoding Complexity
Performance of D dimensional MDTPC
91
3.4.1
Convergence Behaviour
92
3.4.2
Bit Error Rate Performance
95
3.4.3
Performance of DBRO Codeword Sequences
99
Summary
100
SPACE-TIME MULTIDIMENSIONAL TURBO
PRODUCT CODED MIMO-OFDM SYSTEM
102
4.1
Introduction
102
4.2
Space-time MDTPC-MIMO System
103
4.2.1
Zero Forcing Receiver
107
4.2.2
Maximum Likelihood Receiver
111
4.3
Channel Capacity Analysis
113
4.4
ST-MDTPC-MIMO Application on OFDM System
116
4.5
Simulation Results and Discussion
118
4.5.1
120
ST-MDTPC-MIMO System
4.5.1.1 Performance Comparison of STMDTPC-MIMO and STBC
122
4.5.1.2 Convergence Behaviour of MDTPC
Decoder in MIMO System
124
4.5.1.3 Bit Error Rate Performance of STMDTPC-MIMO System
130
4.5.1.4 Diversity Gain and Coding Gain
133
4.5.1.5 Bit-Interleaved ST-MDTPC-MIMO
System
135
4.5.1.6 Link Level Capacity of ST-MDTPCMIMO System
4.5.2
Performance of ST-MDTPC-MIMO-OFDM
System
4.6
138
Summary
140
145
x
5
SPATIAL MULTIPLEXING ST-MDTPC-MIMOOFDM SYSTEM WITH ANTENNA GROUPING
148
5.1
Introduction
148
5.2
Spatial Multiplexing ST-MDTPC-MIMO System
with Antenna Grouping
149
5.2.1
AG-SMST-MDTPC-MIMO Schemes
149
5.2.1.1 Zero Forcing Receiver
152
5.2.1.2 ML Receiver
155
5.3
Channel Capacity Analysis
5.4
AG-SMST-MDTPC-MIMO Application on OFDM
156
System
159
5.5
Simulation Model
161
5.6
Simulation Results and Discussion
163
5.6.1
163
AG-SMST-MDTPC-MIMO System
5.6.1.1 Bit Error Rate Performance of AGSMST-MDTPC-MIMO System
164
5.6.1.2 The Link Level Capacity of AGSMST-MDTPC-MIMO System
5.6.2
Bit Error Rate Performance of AG-SMSTMDTPC-MIMO-OFDM System
5.7
6
169
Summary
172
174
CHANNEL ESTIMATION STRATEGY FOR AGSMST-MDTPC-MIMO-OFDM SYSTEM
176
6.1
Introduction
176
6.2
Least Square Channel Estimation
178
6.3
Channel Estimation Analysis
181
6.3.1
Optimal Training Over One OFDM Frame
183
6.3.2
Optimal Training Over Multiple OFDM
Frames
6.4
6.5
186
Channel Estimation Enhancement
188
6.4.1
191
Frequency Domain Analysis of RLS Method
Simulation Model
192
xi
6.6
Simulation Results and Discussion
194
6.6.1
Analytical and Simulated MSE
194
6.6.2
Error Rate and MSE Performance of LS
6.6.3
6.7
7
Channel Estimation
195
RLS Enhancement
200
Summary
202
CONCLUSION AND FUTURE WORKS
204
7.1
Introduction
204
7.2
Future Works
208
REFERENCES
210-227
Appendices A-D
228-248
xii
LIST OF TABLES
TABLE NO.
TITLE
PAGE
2.1
Orthogonal STBC with code rate above ½
19
2.2
Comparison of STBC and STTC
26
2.3
Layering in DBLAST
30
2.4
MIMO receivers
33
2.5
Comparison of the approaches in exploiting MIMO
34
2.6
Major parameters for OFDM PHY of 802.11a WLAN
standard
59
4.1
Bit error rate of ST-MDTPC-MIMO system
129
4.2
Bit error performance of 3D, 4D, 5D ST-MDTPC-MIMO
system
132
Diversity gain of 2Tx2Rx and 3Tx3Rx ST-MDTPCMIMO systems
134
Coding gain of ST-MDTPC-MIMO system with 2Tx2Rx
and 3Tx3Rx
134
Coding gain advantage of 3Tx3Rx ST-MDTPC-MIMO
system
137
Coding gain advantage of 4D and 5D ST-MDTPC-MIMO
over 3D ST-MDTPC-MIMO system with 4Tx4Rx
antennas
138
Simulation parameters of ST-MDTPC-MIMO-OFDM
system
141
Bit error rate of 1G, 2G, and 3G 2Tx2Rx using 3D and 4D
MDTPC
165
Bit error rate of the 2G, 3G, 4G 4D AG-SMST-MDTPCMIMO system at SNR 5 dB
166
4.3
4.4
4.5
4.6
4.7
5.1
5.2
xiii
5.3
Bit error rate at transmission rate of 4 bps/Hz and SNR of
10 dB
168
Bit error rate and transmission rate of the system with 1G,
2G, and 3G at channel delay spread of 100 ns
173
Effect of delay spread on AG-SMST-MDTPC-MIMOOFDM system at bit error rate of 10-6
173
6.1
λ optimum for slow and fast fading channel
195
6.2
Bit error rate of the system at SNR of 18 dB
196
6.3
Bit error rate at SNR 18 dB for training over two and four
OFDM frames
199
MSE of channel estimation over two and four OFDM
frames at SNR of 18 dB
199
Bit error rate of the system employing RLS and LS
channel estimation
201
MSE of the system employing RLS and LS channel
estimation
202
5.4
5.5
6.4
6.5
6.6
xiv
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
2.1
Faded signal envelope
11
2.2
Power spectrum of the received signal after traveling the
multipath channel
12
Antenna configuration in multiple antennas wireless
system, Tx = transmitter, Rx = receiver
14
2.4
Exploiting MIMO channel methods
15
2.5
Space and time diversity a) receive diversity using
MRRC, b) transmit diversity (Alamouti, 1998)
17
2.6
Encoder block diagram for STBC
21
2.7
A four state STTC, R = 2 bits /s/Hz using QPSK
23
2.8
Transmitter structure for BLAST (Foschini, 1996)
27
2.9
Packet structure for BLAST, NT = NR =4.
29
2.10
Block diagram of the MIMO-OFDM system with space,
time, and frequency diversity
35
2.11
Block diagram of an OFDM system (Proakis, 2000)
37
2.12
General block diagram of space-time coded OFDM
system
39
2.13
Convolutional encoder with memory length k = 7
44
2.14
Recursive systematic codes with parallel concatenation:
turbo encoder
44
2.15
Serial concatenated encoding representation of the TPC
46
2.16
A geometrically representation of the encoding process
of TPC
47
2.3
xv
2.17
Turbo product codeword, a) fully product code b)
parallel concatenated code, c) shortened product code
48
2.18
Serial soft-iterative decoder for TPC
52
2.19
Pilot symbol pattern for MIMO-OFDM with 2 transmit
antennas
55
Data and pit symbols arrangement in the transmitted
frame
56
Transmitted and receiver block diagram for OFDM PHY
802.11a
58
2.22
Flowchart of research methodology
62
3.1
MDTPC codeword formatting process
65
3.2
DBRO algorithm for MDTPC
58
3.3
Flowchart of DBRO algorithm
59
3.4
D MDTPC encoder using DBRO bit mapper
70
3.5
The 2D MDTPC codeword, a) two dimensions codeword
block, b) corresponding two possible codeword
sequences
73
Encoding and possible codeword using DBRO algorithm
of 2D MDTPC with MATLAB programming, a) data
block, b) codeword block, c) codeword sequences
74
3.7
The equivalent algorithm for the mapping function ξ1.
76
3.8
A typical 3D MDTPC with dimension of n1 = 4, n2 = 5,
and n3 =3
77
The common codeword x1 of the 3D MDTPC given in
example
77
The second possible codeword of the 3D MDTPC given
in example
77
The third possible codeword of the 3D MDTPC given in
example
78
The forth possible codeword of the 3D MDTPC given in
example
78
The fifth possible codeword of the 3D MDTPC given in
example
78
2.20
2.21
3.6
3.9
3.10
3.11
3.12
3.13
xvi
3.14
The sixth possible codeword of the 3D MDTPC given in
example
79
Codeword sequences of the (4x5x3) 3D MDTPC as
parallel code
80
The (4x5x3) 3D MDTPC codewords, a) data block, b)
codeword block, c) codeword sequences
81
Codeword block of 4D MDTPC presented in 3D
MDTPC codeword blocks
82
3.18
DBRO algorithm for 4D MDTPC
83
3.19
Representation of a 5D MDTPC codeword into several
3D MDTPC codeword
84
DBRO algorithm for generating 5D MDTPC codeword
sequences
86
3.21
Parallel Decoder for D-dimensional MDTPC
88
3.22
Soft input soft output decoder component
88
3.23
Flowchart of the parallel decoder
90
3.24
Simulation model for error correcting MDTPC system
92
3.25
Convergence behaviour of the 2D, 3D, 4D, and 5D
MDTPC with 4QAM modulation over AWGN channel at
SNR 6 dB
93
Convergence behaviour of the 4D MDTPC decoder using
16QAM modulation over fast flat Rayleigh channel
94
Bit error rate performance of 2D, 3D, 4D, and 5D
MDTPC using BPSK over AWGN channel
95
Bit error rate performance of 2D, 3D, 4D, and 5D
MDTPC using BPSK over flat Rayleigh fading channel
at 4 iterations
96
Bit error rate performance of 2D, 3D, 4D, and 5D
MDTPC with 4QAM modulation
97
Bit error rate performance of 2D, 3D, 4D, and 5D
MDTPC using 16QAM over flat Rayleigh fading channel
at 6 iterations
99
The performance of the MDTPC for different selected
codeword using BSPK modulation over flat Rayleigh
fading channel
100
3.15
3.16
3.17
3.20
3.26
3.27
3.28
3.29
3.30
3.31
xvii
4.1
ST-MDTPC-MIMO transmitter system
104
4.2
ZF ST-MDTPC-MIMO receiver
104
4.3
ML receiver for space-time product coded multiple
antennas
112
OFDM transmission scheme for ST-MDTPC-MIMO
system
118
4.5
Simulation model of ST- MDTPC-MIMO-OFDM system
121
4.6
Convergence behaviour of the proposed parallel decoder
of 2D ST-MDTPC code applying in the various multiple
antennas schemes at SNR of 6 dB
123
Performance comparisons of the ST-MDTPC and STBCMDTPC
124
Bit error rate performance of the 2Tx2RX 2D STMDTPC-MIMO system for a number of decoding
iterations
125
Convergence behaviour of 3D ST-MDTPC-MIMO
system at SNR=3 dB
126
Bit error rate performance of the 2Tx2Rx 3D STMDTPC-MIMO for a number of decoding iterations
126
Convergence behaviour of 4D ST-MDTPC-MIMO
system at SNR=3 dB
127
Bit error rate performance of the 2Tx2Rx 4D STMDTPC-MIMO system for certain number of decoding
iterations
127
Convergence behaviour of 5D ST-MDTPC-MIMO
system at SNR=3 dB
128
Bit error rate performance of the 2Tx2Rx 5D STMDTPC-MIMO system for certain number of decoding
iterations
128
Bit error rate performance of the 3D ST-MDTPC-MIMO
system
131
Bit error rate performance of the 4D ST-MDTPCMIMO-system
131
Bit error rate performance of the 5D ST-MDTPC-MIMO
system
132
4.4
4.7
4.8
4.9
4.10
4.11
4.12
4.13
4.14
4.15
4.16
4.17
xviii
4.18
4.19
4.20
4.21
4.22
4.23
4.24
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
Diversity gain and coding gain of the ST-MDTPCMIMO system employing 2Tx2Rx and 3Tx3Rx
134
Bit error rate of the 2Tx2Rx ST-MDTPC system using
BPSK, 4QAM, and 16QAM modulation
136
Bit error rate of the 3Tx3Rx ST-MDTPC-MIMO using
BPSK, 4QAM and 16QAM modulation
137
Bit error rate of 4Tx4Rx ST-MDTPC system using
BPSK, 4QAM, and 16QAM
138
LLC of the 2Tx2Rx schemes using HCM, BICM, and 5D
ST-MDTPC-MIMO schemes
140
Bit error rate performance of the 3Tx3Rx 3D STMDTPC-MIMO-OFDM system using 16QAM
modulation and Doppler frequency at 100 Hz
143
Bit error rate performance of the 3D ST-MDTPCMIMO-OFDM employing 3Tx3Rx and 4Tx4Rx (τD = 50
ns)
144
Transmitter structure of the spatial multiplexing product
coded MIMO system with antenna grouping
150
The ZF receiver structure of the AG-SMST-MDTPCMIMO system
153
The ML receiver structure of spatial multiplexing
product coded MIMO
156
Block diagram of AG-SMST-MDTPC-MIMO-OFDM
system
160
Simulation model of AG-SMST-MDTPC-MIMO-OFDM
system
162
Bit error rate performance of the AG-SMST-MDTPCMIMO system employing 1G, 2G, and 3G 2Tx2Rx
164
Bit error rate performance of the 4D ST-MDTPC system
employing 2G, 3G, and 4G with 3Tx3Rx, 4Tx4Rx, and
5Tx5Rx
166
The 4 bits/s/Hz transmission rate 3Tx3Rx 3D AGSMST-MDTPC-MIMO system
167
The 8 bps/Hz transmission rate 4Tx4Rx 4D AG-SMSTMDTPC-MIMO system
168
xix
5.10
5.11
5.12
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
6.10
Link level capacity of the 2G 4Tx4Rx 4D AG-SMSTMDTPC-MIMO system using ML receiver and ZF
receiver.
170
Link level capacity of the 3G 4Tx4Rx 4D AG-SMSTMDTPC-MIMO system using ML receiver and ZF
receiver.
171
Bit error rate performance of 3D AG-SMST-MDTPCMIMO-OFDM system for 2G and 3G 3Tx3Rx 16QAM,
fD = 100Hz
172
ZF receiver of the AG-SMST-MDTPC-MIMO-OFDM
with channel estimator
177
Training symbol over OFDM frame, a) one frame, b) two
frames
186
Simulation model of the 2G 3TxRx 3D AG-SMSTMDTPC-MIMO-OFDM system with channel estimator
193
MSE profile as a function of λ for simulation and
analysis results at SNR = 20 dB (non time varying
channel over an entire OFDM frame)
195
Bit error rate performance with different training
sequences for channel estimation over one OFDM frame
196
MSE of channel estimation for training over one OFDM
frame
197
Bit error rate performance with training for channel
estimation over two and four OFDM frames
198
MSE of channel estimation for training over two and four
OFDM frames
200
Bit error rate performance as SNR function with optimal
tracking factor λ
201
MSE as SNR function of the 2G 3TxRx 3D AG-SMSTMDTPC-MIMO-OFDM system with optimal tracking
factor λ
202
xx
LIST OF ABBREVIATIONS
AWGN
-
Additive White Gaussian Noise
BPSK
-
Binary Phase Shift Keying modulation
CWEF
-
Conditional Weight Enumerating Function
dB
-
decibel
IOWEF
-
Input-Output Weight Enumerating Function
LLR
-
Log-likelihood Ratio
LOS
-
Line Of Sight
LS
-
Least Square
MDTPC
-
Multidimensional Turbo Product Codes
MIMO
-
Multiple Input Multiple Output
MISO
-
Multiple Input Single Output
ML
-
Maximum Likelihood
MSE
-
Mean Square Error
OFDM
-
Orthogonal Frequency Division Multiplexing
TPC
-
Turbo Product Code
PEP
-
Pairwise Error Probability
PSA
-
Pilot Symbol Assisted
QAM
-
Quadrature Amplitude Modulation
RLS
-
Recursive Least Square
SIMO
-
Single Input Multiple Output
SISO
-
Single Input Single Output
SNR
-
Signal to Noise Ratio
SPC
-
Single Parity Check code
STBC
-
Space Time Block Codes
STTC
-
Space Time Trellis Codes
ZF
-
Zero Forcing
xxi
LIST OF SYMBOLS
A(.)
-
IOWEF, input output weight enumerating function
Bh
-
Bit error multiplicity
bb
-
Information bits
C
-
The link level capacity, channel capacity
D
-
Number dimension of multi dimensional turbo product code
Es
-
Energy of transmitted symbol
E{.}
-
Expectation function, running time mean
F
-
Frame length of transmitted block (symbols)
H,h
-
Channel response
H(.)
-
Entropy
I
-
Identity matrix
I(.)
-
Mutual information
j
-
Imaginary sign of complex number
kd
-
Information block length, encoder input length
k
-
Constellation component order
M
-
Modulation level, number of constellation components
m, n, t
-
Order for transmit antenna, order for receive antenna, and order
of transmitted symbol
N
-
Codeword length of a product code (bits)
N0
-
Power of additive noise
NT
-
Number of transmit antennas
NR
-
Number of receive antennas
NG
-
Number of antenna groups
nd
-
Codeword length of component code at dth dimension
xxii
Pe
-
Probability of bit error
Pr(.)
-
Probability of an event
p(.)
-
Conditional probability
s
-
Transmitted signal
sk
-
Constellation components, transmitted symbols
W,w
-
AWGN noise
X, X
-
Coded bits
Y,y
-
Received signal matrix
δd
-
Hamming distance of a codeword
^
-
Complex number set
\
-
Real number set
ℜ(.)
Real part of complex number
]
Integer number set
(.)
T
-
Matrix transpose
π
-
Pi = 22/7 = 3.14159
ξ
-
DBRO mapping function
Λ(.)
-
LLR = log-likelihood ratio
Λe
-
Extrinsic information
Λc
-
Soft channel output
O(.)
-
Computational complexity
S
-
Set of constellation components
C(.)
-
Component code of multidimensional product code
(.)H
-
Hermitian matrix
(.)*
-
Complex conjugate
(.)-1
-
Matrix inverse
( .)
-
Moore-Penrose pseudo-matrix inverse
†
xxiii
LIST OF APPENDICES
APPENDIX
TITLE
PAGE
A
Complex orthogonal STBC with rate more than ½.
228
B
Matlab source code of DBRO Algorithm for 3D
MDTPC
233
C1
The codeword sequences of the 4D MDTPC
235
C2
The mapping function of the codeword sequences
237
C3
A typical 4D MDTPC with dimension 5×4×3×2
238
C4
The codeword sequences of the 4D SPC-MDTPC
with dimension of 5×4×3×2
238
Simple truncation of 3D MDTPC with C(10,9,2)
to result 896 coded bits within the codeword
248
D