Multicarrier Modulation with Low PAR: Applications to DSL and Wireless

165 Pages·2002·13.891 MB·English

by  Jose Tellado (auth.)

MULTICARRIER MODULATION
WITH LOW PAR
Applications to DSL and Wireless
THE KLUWER INTERNATIONAL SERIES
IN ENGINEERING AND COMPUTER SCIENCE
MULTICARRIER MODULATION
WITH LOW PAR
Applications to DSL and Wireless
by
Jose Tellado
Stanford University
KLUWER ACADEMIC PUBLISHERS
NEW YORK, BOSTON, DORDRECHT, LONDON, MOSCOW
eBookISBN: 0-306-47039-X
Print ISBN: 0-7923-7988-8
©2002 Kluwer Academic Publishers
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Print ©2000 Kluwer Academic Publishers
Dordrecht
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To Louise
Contents
List of Figures ix
Foreword xiii
Preface xv
Acknowledgments xvii
1. INTRODUCTION 1
1. Outline of Book 2
2. MULTICARRIER MODULATION 5
1. Multicarrier Modulation 6
2. Partitioning for Vector Coding 8
3. Partitioning for DMT and OFDM 9
4. Loading Principles 11
3. PEAK TO AVERAGE RATIO 15
1. Multicarrier Signals 15
2. Peak to Average Ratio 22
3. Statistical Properties of Multicarrier Signals 26
4. Bounds on Continuous-Time PAR using Discrete-Time
Samples 29
5. Description of Memoryless Nonlinearity 39
6. Effect of Nonlinearities on System Performance 43
6.1 PSD Degradation 44
6.2 BER Increase 44
7. Limits for Distortionless PAR Reduction 52
8. Techniques for PAR Reduction 55
8.1 PAR Reduction with Distortion 56
8.2 Distortionless PAR Reduction 57
8.2.1 Coding 58
8.2.2 Discrete Parameter Optimization 59
8.2.3 Continuous Parameter Optimization 60
viii MULTICARRIER MODULATION WITH LOW PAR
9. New PAR Reduction Structures 62
4. PAR REDUCTION BY TONE RESERVATION 65
1. Problem Formulation 66
2. PAR Reduction Signals for Tone Reservation 68
3. Optimal PAR Reduction Signals for Tone Reservation 71
4. Simple Gradient Algorithms with Fast Convergence 77
5. Iterative PAR Reduction as a Controlled Clipper 84
6. Tone Reservation Kernel Design 85
6.1 Computing Peak Reduction Kernels 86
6.2 Choosing the PRT Set 88
6.3 Numerical Computation of PRT and Kernel 91
7. Results 93
5. PAR REDUCTION BY TONE INJECTION 97
1. PAR Reduction using Generalized Constellations 98
2. Power Increase 103
3. Maximum PAR Reduction per Dimension Translation 107
4. Simple Algorithms for Computing 110
5. Results 112
6. Conclusions 116
6. MAXIMUM LIKELIHOOD DETECTION OF
DISTORTED MULTICARRIER SIGNALS 119
1. Memoryless Nonlinearity effects on Achievable Rate 120
2. Maximum Likelihood (ML) Detection 124
3. Numerical Results 132
4. Conclusions 134
7. SUMMARY AND CONCLUSIONS 137
1. Book Summary 137
Index
149
List of Figures
3.1 DMT/OFDM Transmitter Block Diagram. 17
3.2 Different Multicarrier Symbols: A) Basic, B) With
CP and C) With CP and windowed extended CP
and CS. 19
3.3 Multicarrier Signals from Figure 3.2. 20
3.4 PSD of the discrete-time multicarrier signal in (3.14)
for N = 512, L = 4 and raised cosine windows with
different roll-off lengths. 21
3.5 CCDF of for N = 256, 512, 1024, 2048. 28
3.6 CCDF of for L= 1,2,4,16. 30
3.7 CCDF of for L = 2, 4 given
32
3.8 Upper bound on the maximum of given 34
3.9 pdf of (normalized by vs. a nor-
malized Gaussian. 36
3.10 CCDF of for L = 4, 8 given
38
3.11 CCDF of given
39
3.12 CCDF of at different points of an ADSL
modem for an Ideal Over-Sampled PAR reduction
method. 40
3.13 PSD for with tapered window fol-
lowed by a limiter. 45
3.14 Analytical and simulated SER for N = 512 and
64QAM for the SL(8 dB) nonlinearity. 49
x MULTICARRIER MODULATION WITH LOW PAR
3.15 Analytical and simulated SER for N = 512 and
1024QAM for the SL (11 dB) nonlinearity. 50
3.16 Diagram for the pdf of and 51
3.17 Relative Capacity of Peak-Power-Limited AWGN
channel. 54
3.18 Additive model for PAR reduction. 63
4.1 Illustration of the Tone Reservation structure. 70
4.2 CCDF of for N = 512 when
and with Randomly-Optimized
set 77
4.3 Illustration of the SCR gradient algorithm. 82
4.4 SCR improvement for a Structured tone set and
a Randomly-Optimized set with SCR gradient,
technique. 83
4.5 CCDF of when N = 512 and
for two index choices, Contiguous tones,
and Randomly-Optimized
set 89
4.6 CDF and CCDF of the Kernel’s largest sidelobe
for R = 26 and N = 512. 92
4.7 distribution for
and Contiguous tone set with
94
4.8 distribution for
and with Randomly Optimized set 95
5.1 Block Diagram for the Tone Injection PAR reduc-
tion method. 100
5.2 The constellation value A is the minimum energy
point of the equivalent set 101
5.3 Generalized constellation for 16QAM for a given
value D, when and 102
5.4 Tone Injection PAR CCDF for N = 64, 16QAM
and 112
5.5 Tone Injection PAR CCDF for N = 256, 16QAM
and for iterations 113
Contents xi
5.6 Sample CCDF at four different points of an ADSL
transmitter: standard IFFT output, oversampled
Tone Injection PAR reduction output, oversam-
pled FIR HPF output (L = 2), and oversampled
FIR LPF output (L = 4). 114
5.7 Same as Figure 5.6 with Butterworth HPF and
Butterworth LPF. 115
5.8 Same as Figure 5.6 for the ADSL transmit filter
provided by Pairgain. 116
5.9 Peak CCDF at the 4 × oversampled filtered output
when the transmit filters are included in the PAR
reduction algorithm. 117
6.1 Channel nonlinear model for computing mutual in-
formation. 121
6.2 Channel capacity and mutual information for a
ClipLevel of 5 dB and 7 dB for the Soft Limiter
nonlinearity. 123
6.3 Relative mutual information for a ClipLevel of
5 dB, 7 dB and 9 dB for the SL nonlinearity. 124
6.4 Relative mutual information for a ClipLevel of
5 dB, 7 dB and 9 dB for the Solid-State Power
Amplifier nonlinearity. 125
6.5 Channel capacity and practical data rates for a
ClipLevel of 5 dB, 7 dB and 9 dB with a SL if
the distortion is assumed to be AWGN. 129
6.6 Iterative (quasi-ML) nonlinear distortion canceler. 130
6.7 Performance of the iterative-ML algorithm for a SL
nonlinearity when N = 512, L = 1 and ClipLevel =
9 dB. 133
6.8 Performance of the iterative-ML algorithm for a
SSPA nonlinearity when N = 512, L = 1 and
ClipLevel = 11 dB. 134
6.9 Performance of the iterative-ML algorithm for the
Gaussian clip windowing nonlinearity with Gaus-
sian clip windowing when N = 4096, L = 2 and
ClipLevel = 9 dB. 135
6.10 Performance of the iterative-ML algorithm for a SL
nonlinearity when N = 4096, L = 2 and ClipLevel =
8 dB. 136