W. Pam Siriwongpairat, PhD, is a Wireless Communications Specialist with Meteor Communications Corporation. From January to May 2006, she was a research associate in the Department of Electrical and Computer Engineering and Institute for Systems Research at the University of Maryland, College Park. Her current research interests span a broad range of areas from digital signal processing to wirelesscommunications and networking, including ultra-wideband communications, space-time-frequency coding for multi-antenna communications, cross-layer design for wireless networks, communications in mobile ad hoc networks and wireless sensor networks, OFDM systems, and software-defined radio and cognitive radio technologies.K. J. Ray Liu, PhD, is Professor and Associate Chair for Graduate Studies and Research of Electrical and Computer Engineering Department at the University of Maryland, College Park. Dr. Liu is the recipient of numerous honors and awards including best paper awards from IEEE Signal Processing Society (twice), IEEE Vehicular Technology Society, and EURASIP, as well as recognitions from the University of Maryland including university-level Distinguished Scholar-Teacher Award, Invention of the Year Award, and college-level Poole and Kent Company Senior Faculty Teaching Award.

• Preface xiiiChapter 1 Introduction 11.1 Overview of UWB 11.2 Advantages of UWB 31.3 UWB Applications 41.4 UWB Transmission Schemes 51.5 Challenges for UWB 7Chapter 2 Channel Characteristics 92.1 Large-Scale Models 102.1.1 Path Loss Models 102.1.2 Shadowing 112.2 Small-Scale Models 122.2.1 Tap-Delay-Line Fading Model 132.2.2 Δ− K Model 142.2.3 Saleh–Valenzuela Model 152.2.4 Standard UWB Channel Model 16Chapter 3 UWB: Single-Band Approaches 193.1 Overview of Single-Band Approaches 203.2 Modulation Techniques 213.2.1 Pulse Amplitude Modulation 213.2.2 On–Off Keying 223.2.3 Phase Shift Keying 223.2.4 Pulse Position Modulation 233.3 Multiple Access Techniques 233.3.1 Time-Hopping UWB 243.3.2 Direct-Sequence UWB 253.4 Demodulation Techniques 263.4.1 Received Signal Model 263.4.2 Correlation Receiver 273.4.3 RAKE Receiver 283.5 MIMO Single-Band UWB 303.5.1 MIMO Space–Time-Coded Systems 303.5.2 Space–Time-Coded UWB Systems 323.6 Performance Analysis 373.6.1 TH-BPPM 383.6.2 TH-BPSK 413.6.3 DS-BPSK 423.7 Simulation Results 443.8 Chapter Summary 51Chapter 4 UWB: Multiband OFDM Approach 534.1 Overview of Multiband OFDM Approach 544.1.1 Fundamental Concepts 544.1.2 Signal Model 564.2 IEEE 802.15.3a WPAN Standard Proposal 574.2.1 OFDM Parameters 574.2.2 Rate-Dependent Parameters 584.2.3 Operating Band Frequencies 594.2.4 Channelization 604.3 Physical Layer Design 614.3.1 Scrambler and De-scrambler 624.3.2 Convolutional Encoder and Viterbi Decoder 624.3.3 Bit Interleaver and De-interleaver 634.3.4 Constellation Mapper 674.3.5 OFDM Modulation 674.4 MAC Layer Design 694.4.1 Network Topology 694.4.2 Frame Architecture 714.4.3 Network Operations 724.5 Chapter Summary 73Chapter 5 MIMO Multiband OFDM 755.1 MIMO-OFDM Communications 765.2 MIMO Multiband OFDM System Model 785.2.1 Transmitter Description 785.2.2 Channel Model 805.2.3 Receiver Processing 805.3 Performance Analysis 825.3.1 Independent Fading 835.3.2 Correlated Fading 865.4 Simulation Results 895.5 Chapter Summary 94Chapter 6 Performance Characterization 976.1 System Model 986.2 Performance Analysis 996.2.1 Average PEP Analysis 1006.2.2 Approximate PEP Formulation 1026.2.3 Outage Probability 1066.3 Analysis for MIMO Multiband OFDM Systems 1106.3.1 MIMO Multiband OFDM System Model 1106.3.2 Pairwise Error Probability 1116.3.3 Example: Repetition STF Coding Based on Alamouti’s Structure 1136.4 Simulation Results 1146.5 Chapter Summary 120Chapter 7 Performance Under Practical Considerations 1217.1 System Model 1227.2 Average Signal-to-Noise Ratio 1247.2.1 Expressions of Fading Term ICI and ISI 1247.2.2 Variances of Fading Term ICI and ISI 1277.2.3 Average Signal-to-Noise Ratio and Performance Degradation 1327.3 Average Bit Error Rate 1327.3.1 Overall Spreading Gain of 1 1347.3.2 Overall Spreading Gain of 2 1367.3.3 Overall Spreading Gain of 4 1377.4 Performance Bound 1407.5 Numerical and Simulation Results 1437.5.1 Numerical Results 1437.5.2 Simulation and Numerical Results 1457.6 Chapter Summary 147Appendix: Derivations of A1 A2 B1 and B2 148A.1 Derivation of A1 and A2 149A.2 Derivation of B1 and B2 151Chapter 8 Differential Multiband OFDM 1558.1 Differential Modulation 1568.1.1 Single-Antenna Systems 1568.1.2 MIMO Systems 1578.2 Differential Scheme for Multiband OFDM Systems 1598.2.1 System Model 1598.2.2 Differential Encoding and Transmitting Signal Structure 1608.2.3 Multiband Differential Decoding 1628.3 Pairwise Error Probability 1638.4 Simulation Results 1668.5 Chapter Summary 169Chapter 9 Power-Controlled Channel Allocation 1719.1 System Model 1729.2 Power-Controlled Channel Allocation Scheme 1749.2.1 Generalized SNR for Various Transmission Modes 1759.2.2 PER and Rate Constraint 1769.2.3 Problem Formulation 1779.2.4 Subband Assignment and Power Allocation Algorithm 1789.2.5 Joint Rate Assignment and Resource Allocation Algorithm 1799.3 Simulation Results 1829.3.1 Subband Assignment and Power Allocation 1829.3.2 Joint Rate Assignment and Resource Allocation 1859.4 Chapter Summary 186Chapter 10 Cooperative UWB Multiband OFDM 18910.2 System Model 19110.2.1 Noncooperative UWB 19210.2.2 Cooperative UWB 19310.3 SER Analysis for Cooperative UWB 19410.3.1 Cooperative UWB 19410.3.2 Comparison of Cooperative and Noncooperative UWB 19910.4 Optimum Power Allocation for Cooperative UWB 20110.4.1 Power Minimization Using Cooperative Communications 20110.4.2 Coverage Enhancement Using Cooperative Communications 20510.5 Improved Cooperative UWB 20810.6 Simulation Results 21210.7 Chapter Summary 215References 217Index 227

W. Pam Siriwongpairat, PhD, is a Wireless Communications Specialist with Meteor Communications Corporation. From January to May 2006, she was a research associate in the Department of Electrical and Computer Engineering and Institute for Systems Research at the University of Maryland, College Park. Her current research interests span a broad range of areas from digital signal processing to wirelesscommunications and networking, including ultra-wideband communications, space-time-frequency coding for multi-antenna communications, cross-layer design for wireless networks, communications in mobile ad hoc networks and wireless sensor networks, OFDM systems, and software-defined radio and cognitive radio technologies.K. J. Ray Liu, PhD, is Professor and Associate Chair for Graduate Studies and Research of Electrical and Computer Engineering Department at the University of Maryland, College Park. Dr. Liu is the recipient of numerous honors and awards including best paper awards from IEEE Signal Processing Society (twice), IEEE Vehicular Technology Society, and EURASIP, as well as recognitions from the University of Maryland including university-level Distinguished Scholar-Teacher Award, Invention of the Year Award, and college-level Poole and Kent Company Senior Faculty Teaching Award.

• Preface xiiiChapter 1 Introduction 11.1 Overview of UWB 11.2 Advantages of UWB 31.3 UWB Applications 41.4 UWB Transmission Schemes 51.5 Challenges for UWB 7Chapter 2 Channel Characteristics 92.1 Large-Scale Models 102.1.1 Path Loss Models 102.1.2 Shadowing 112.2 Small-Scale Models 122.2.1 Tap-Delay-Line Fading Model 132.2.2 Δ− K Model 142.2.3 Saleh–Valenzuela Model 152.2.4 Standard UWB Channel Model 16Chapter 3 UWB: Single-Band Approaches 193.1 Overview of Single-Band Approaches 203.2 Modulation Techniques 213.2.1 Pulse Amplitude Modulation 213.2.2 On–Off Keying 223.2.3 Phase Shift Keying 223.2.4 Pulse Position Modulation 233.3 Multiple Access Techniques 233.3.1 Time-Hopping UWB 243.3.2 Direct-Sequence UWB 253.4 Demodulation Techniques 263.4.1 Received Signal Model 263.4.2 Correlation Receiver 273.4.3 RAKE Receiver 283.5 MIMO Single-Band UWB 303.5.1 MIMO Space–Time-Coded Systems 303.5.2 Space–Time-Coded UWB Systems 323.6 Performance Analysis 373.6.1 TH-BPPM 383.6.2 TH-BPSK 413.6.3 DS-BPSK 423.7 Simulation Results 443.8 Chapter Summary 51Chapter 4 UWB: Multiband OFDM Approach 534.1 Overview of Multiband OFDM Approach 544.1.1 Fundamental Concepts 544.1.2 Signal Model 564.2 IEEE 802.15.3a WPAN Standard Proposal 574.2.1 OFDM Parameters 574.2.2 Rate-Dependent Parameters 584.2.3 Operating Band Frequencies 594.2.4 Channelization 604.3 Physical Layer Design 614.3.1 Scrambler and De-scrambler 624.3.2 Convolutional Encoder and Viterbi Decoder 624.3.3 Bit Interleaver and De-interleaver 634.3.4 Constellation Mapper 674.3.5 OFDM Modulation 674.4 MAC Layer Design 694.4.1 Network Topology 694.4.2 Frame Architecture 714.4.3 Network Operations 724.5 Chapter Summary 73Chapter 5 MIMO Multiband OFDM 755.1 MIMO-OFDM Communications 765.2 MIMO Multiband OFDM System Model 785.2.1 Transmitter Description 785.2.2 Channel Model 805.2.3 Receiver Processing 805.3 Performance Analysis 825.3.1 Independent Fading 835.3.2 Correlated Fading 865.4 Simulation Results 895.5 Chapter Summary 94Chapter 6 Performance Characterization 976.1 System Model 986.2 Performance Analysis 996.2.1 Average PEP Analysis 1006.2.2 Approximate PEP Formulation 1026.2.3 Outage Probability 1066.3 Analysis for MIMO Multiband OFDM Systems 1106.3.1 MIMO Multiband OFDM System Model 1106.3.2 Pairwise Error Probability 1116.3.3 Example: Repetition STF Coding Based on Alamouti’s Structure 1136.4 Simulation Results 1146.5 Chapter Summary 120Chapter 7 Performance Under Practical Considerations 1217.1 System Model 1227.2 Average Signal-to-Noise Ratio 1247.2.1 Expressions of Fading Term ICI and ISI 1247.2.2 Variances of Fading Term ICI and ISI 1277.2.3 Average Signal-to-Noise Ratio and Performance Degradation 1327.3 Average Bit Error Rate 1327.3.1 Overall Spreading Gain of 1 1347.3.2 Overall Spreading Gain of 2 1367.3.3 Overall Spreading Gain of 4 1377.4 Performance Bound 1407.5 Numerical and Simulation Results 1437.5.1 Numerical Results 1437.5.2 Simulation and Numerical Results 1457.6 Chapter Summary 147Appendix: Derivations of A1 A2 B1 and B2 148A.1 Derivation of A1 and A2 149A.2 Derivation of B1 and B2 151Chapter 8 Differential Multiband OFDM 1558.1 Differential Modulation 1568.1.1 Single-Antenna Systems 1568.1.2 MIMO Systems 1578.2 Differential Scheme for Multiband OFDM Systems 1598.2.1 System Model 1598.2.2 Differential Encoding and Transmitting Signal Structure 1608.2.3 Multiband Differential Decoding 1628.3 Pairwise Error Probability 1638.4 Simulation Results 1668.5 Chapter Summary 169Chapter 9 Power-Controlled Channel Allocation 1719.1 System Model 1729.2 Power-Controlled Channel Allocation Scheme 1749.2.1 Generalized SNR for Various Transmission Modes 1759.2.2 PER and Rate Constraint 1769.2.3 Problem Formulation 1779.2.4 Subband Assignment and Power Allocation Algorithm 1789.2.5 Joint Rate Assignment and Resource Allocation Algorithm 1799.3 Simulation Results 1829.3.1 Subband Assignment and Power Allocation 1829.3.2 Joint Rate Assignment and Resource Allocation 1859.4 Chapter Summary 186Chapter 10 Cooperative UWB Multiband OFDM 18910.2 System Model 19110.2.1 Noncooperative UWB 19210.2.2 Cooperative UWB 19310.3 SER Analysis for Cooperative UWB 19410.3.1 Cooperative UWB 19410.3.2 Comparison of Cooperative and Noncooperative UWB 19910.4 Optimum Power Allocation for Cooperative UWB 20110.4.1 Power Minimization Using Cooperative Communications 20110.4.2 Coverage Enhancement Using Cooperative Communications 20510.5 Improved Cooperative UWB 20810.6 Simulation Results 21210.7 Chapter Summary 215References 217Index 227

W. Pam Siriwongpairat, PhD, is a Wireless Communications Specialist with Meteor Communications Corporation. From January to May 2006, she was a research associate in the Department of Electrical and Computer Engineering and Institute for Systems Research at the University of Maryland, College Park. Her current research interests span a broad range of areas from digital signal processing to wirelesscommunications and networking, including ultra-wideband communications, space-time-frequency coding for multi-antenna communications, cross-layer design for wireless networks, communications in mobile ad hoc networks and wireless sensor networks, OFDM systems, and software-defined radio and cognitive radio technologies.K. J. Ray Liu, PhD, is Professor and Associate Chair for Graduate Studies and Research of Electrical and Computer Engineering Department at the University of Maryland, College Park. Dr. Liu is the recipient of numerous honors and awards including best paper awards from IEEE Signal Processing Society (twice), IEEE Vehicular Technology Society, and EURASIP, as well as recognitions from the University of Maryland including university-level Distinguished Scholar-Teacher Award, Invention of the Year Award, and college-level Poole and Kent Company Senior Faculty Teaching Award.

• Preface xiiiChapter 1 Introduction 11.1 Overview of UWB 11.2 Advantages of UWB 31.3 UWB Applications 41.4 UWB Transmission Schemes 51.5 Challenges for UWB 7Chapter 2 Channel Characteristics 92.1 Large-Scale Models 102.1.1 Path Loss Models 102.1.2 Shadowing 112.2 Small-Scale Models 122.2.1 Tap-Delay-Line Fading Model 132.2.2 Δ− K Model 142.2.3 Saleh–Valenzuela Model 152.2.4 Standard UWB Channel Model 16Chapter 3 UWB: Single-Band Approaches 193.1 Overview of Single-Band Approaches 203.2 Modulation Techniques 213.2.1 Pulse Amplitude Modulation 213.2.2 On–Off Keying 223.2.3 Phase Shift Keying 223.2.4 Pulse Position Modulation 233.3 Multiple Access Techniques 233.3.1 Time-Hopping UWB 243.3.2 Direct-Sequence UWB 253.4 Demodulation Techniques 263.4.1 Received Signal Model 263.4.2 Correlation Receiver 273.4.3 RAKE Receiver 283.5 MIMO Single-Band UWB 303.5.1 MIMO Space–Time-Coded Systems 303.5.2 Space–Time-Coded UWB Systems 323.6 Performance Analysis 373.6.1 TH-BPPM 383.6.2 TH-BPSK 413.6.3 DS-BPSK 423.7 Simulation Results 443.8 Chapter Summary 51Chapter 4 UWB: Multiband OFDM Approach 534.1 Overview of Multiband OFDM Approach 544.1.1 Fundamental Concepts 544.1.2 Signal Model 564.2 IEEE 802.15.3a WPAN Standard Proposal 574.2.1 OFDM Parameters 574.2.2 Rate-Dependent Parameters 584.2.3 Operating Band Frequencies 594.2.4 Channelization 604.3 Physical Layer Design 614.3.1 Scrambler and De-scrambler 624.3.2 Convolutional Encoder and Viterbi Decoder 624.3.3 Bit Interleaver and De-interleaver 634.3.4 Constellation Mapper 674.3.5 OFDM Modulation 674.4 MAC Layer Design 694.4.1 Network Topology 694.4.2 Frame Architecture 714.4.3 Network Operations 724.5 Chapter Summary 73Chapter 5 MIMO Multiband OFDM 755.1 MIMO-OFDM Communications 765.2 MIMO Multiband OFDM System Model 785.2.1 Transmitter Description 785.2.2 Channel Model 805.2.3 Receiver Processing 805.3 Performance Analysis 825.3.1 Independent Fading 835.3.2 Correlated Fading 865.4 Simulation Results 895.5 Chapter Summary 94Chapter 6 Performance Characterization 976.1 System Model 986.2 Performance Analysis 996.2.1 Average PEP Analysis 1006.2.2 Approximate PEP Formulation 1026.2.3 Outage Probability 1066.3 Analysis for MIMO Multiband OFDM Systems 1106.3.1 MIMO Multiband OFDM System Model 1106.3.2 Pairwise Error Probability 1116.3.3 Example: Repetition STF Coding Based on Alamouti’s Structure 1136.4 Simulation Results 1146.5 Chapter Summary 120Chapter 7 Performance Under Practical Considerations 1217.1 System Model 1227.2 Average Signal-to-Noise Ratio 1247.2.1 Expressions of Fading Term ICI and ISI 1247.2.2 Variances of Fading Term ICI and ISI 1277.2.3 Average Signal-to-Noise Ratio and Performance Degradation 1327.3 Average Bit Error Rate 1327.3.1 Overall Spreading Gain of 1 1347.3.2 Overall Spreading Gain of 2 1367.3.3 Overall Spreading Gain of 4 1377.4 Performance Bound 1407.5 Numerical and Simulation Results 1437.5.1 Numerical Results 1437.5.2 Simulation and Numerical Results 1457.6 Chapter Summary 147Appendix: Derivations of A1 A2 B1 and B2 148A.1 Derivation of A1 and A2 149A.2 Derivation of B1 and B2 151Chapter 8 Differential Multiband OFDM 1558.1 Differential Modulation 1568.1.1 Single-Antenna Systems 1568.1.2 MIMO Systems 1578.2 Differential Scheme for Multiband OFDM Systems 1598.2.1 System Model 1598.2.2 Differential Encoding and Transmitting Signal Structure 1608.2.3 Multiband Differential Decoding 1628.3 Pairwise Error Probability 1638.4 Simulation Results 1668.5 Chapter Summary 169Chapter 9 Power-Controlled Channel Allocation 1719.1 System Model 1729.2 Power-Controlled Channel Allocation Scheme 1749.2.1 Generalized SNR for Various Transmission Modes 1759.2.2 PER and Rate Constraint 1769.2.3 Problem Formulation 1779.2.4 Subband Assignment and Power Allocation Algorithm 1789.2.5 Joint Rate Assignment and Resource Allocation Algorithm 1799.3 Simulation Results 1829.3.1 Subband Assignment and Power Allocation 1829.3.2 Joint Rate Assignment and Resource Allocation 1859.4 Chapter Summary 186Chapter 10 Cooperative UWB Multiband OFDM 18910.2 System Model 19110.2.1 Noncooperative UWB 19210.2.2 Cooperative UWB 19310.3 SER Analysis for Cooperative UWB 19410.3.1 Cooperative UWB 19410.3.2 Comparison of Cooperative and Noncooperative UWB 19910.4 Optimum Power Allocation for Cooperative UWB 20110.4.1 Power Minimization Using Cooperative Communications 20110.4.2 Coverage Enhancement Using Cooperative Communications 20510.5 Improved Cooperative UWB 20810.6 Simulation Results 21210.7 Chapter Summary 215References 217Index 227