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Wireless Connectivity
An Intuitive and Fundamental Guide
Buch von Petar Popovski
Sprache: Englisch

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Wireless Connectivity: An Intuitive and Fundamental Guide

Wireless connectivity has become an indispensable part, a commodity associated with the way we work and play. The latest developments, the 5G, next-generation Wi-Fi and Internet of Things connectivity, are the key enablers for widespread digitalization of practically all industries and public sector segments. This immense development within the last three decades have been accompanied by a large number of ideas, articles, patents, and even myths. This book introduces the most important ideas and concepts in wireless connectivity and discusses how these are interconnected, whilst the mathematical content is kept minimal. The book does not follow the established, linear structure in which one starts from the propagation and channels and then climbs up the protocol layers. The structure is, rather, nonlinear, in an attempt to follow the intuition used when one creates a new technology to solve a certain problem.

The target audience is:
* Students in electronics, communication, and networking
* Wireless engineers that are specialized in one area, but want to know how the whole system works, without going through all the details and math
* Computer scientists that want to understand the fundamentals of wireless connectivity, the requirements and, most importantly, the limitations
* Engineers in energy systems, logistics, transport and other vertical sectors that are increasingly reliant on wireless technology
Wireless Connectivity: An Intuitive and Fundamental Guide

Wireless connectivity has become an indispensable part, a commodity associated with the way we work and play. The latest developments, the 5G, next-generation Wi-Fi and Internet of Things connectivity, are the key enablers for widespread digitalization of practically all industries and public sector segments. This immense development within the last three decades have been accompanied by a large number of ideas, articles, patents, and even myths. This book introduces the most important ideas and concepts in wireless connectivity and discusses how these are interconnected, whilst the mathematical content is kept minimal. The book does not follow the established, linear structure in which one starts from the propagation and channels and then climbs up the protocol layers. The structure is, rather, nonlinear, in an attempt to follow the intuition used when one creates a new technology to solve a certain problem.

The target audience is:
* Students in electronics, communication, and networking
* Wireless engineers that are specialized in one area, but want to know how the whole system works, without going through all the details and math
* Computer scientists that want to understand the fundamentals of wireless connectivity, the requirements and, most importantly, the limitations
* Engineers in energy systems, logistics, transport and other vertical sectors that are increasingly reliant on wireless technology
Über den Autor

Petar Popovski is a Professor of Wireless Communications at Aalborg University and Fellow of the IEEE. He received his Dipl.-Ing and M. Sc. degrees in Communication Engineering from the University of Sts. Cyril and Methodius in Skopje and the Ph.D. degree from Aalborg University in 2005. He has over 300 publications in journals, conference proceedings, and edited books. He holds over 30 patents and patent applications. He received an ERC Consolidator Grant (2015), the Danish Elite Researcher award (2016), IEEE Fred W. Ellersick prize (2016), and IEEE Stephen O. Rice prize (2018). He is featured in the list of Highly Cited Researchers 2018, compiled by Web of Science. His research interests are in the area of wireless communication and communication theory.

Inhaltsverzeichnis
Foreword xv

Acknowledgments xix

Acronyms xxi

1 An Easy Introduction to the Shared Wireless Medium 3

1.1 How to Build a Simple Model for Wireless Communication 4

1.1.1 Which Features We Want from the Model 4

1.1.2 Communication Channel with Collisions 4

1.1.3 Trade-offs in the Collision Model 7

1.2 The First Contact 9

1.2.1 Hierarchy Helps to Establish Contact 9

1.2.2 Wireless Rendezvous without Help 11

1.2.3 Rendezvous with Full-Duplex Devices 12

1.3 Multiple Access with Centralized Control 12

1.3.1 A Frame for Time Division 13

1.3.2 Frame Header for Flexible Time Division 14

1.3.3 A Simple Two-Way System that Works Under the Collision Model 15

1.3.4 Still Not a Practical TDMA System 18

1.4 Making TDMA Dynamic 19

1.4.1 Circuit-Switched versus Packet-Switched Operation 19

1.4.2 Dynamic Allocation of Resources to Users 20

1.4.3 Short Control Packets and the Idea of Reservation 22

1.4.4 Half-Duplex versus Full-Duplex in TDMA 24

1.5 Chapter Summary 25

1.6 Further Reading 25

1.7 Problems and Reflections 26

2 Random Access: How to Talk in Crowded Dark Room 29

2.1 Framed ALOHA 30

2.1.1 Randomization that Maximizes the ALOHA Throughput 32

2.2 Probing 35

2.2.1 Combining ALOHA and Probing 39

2.3 Carrier Sensing 39

2.3.1 Randomization and Spectrum Sharing 39

2.3.2 An Idle Slot is Cheap 41

2.3.3 Feedback to the Transmitter 43

2.4 Random Access and Multiple Hops 45

2.4.1 Use of Reservation Packets in Multi-Hop 47

2.4.2 Multiple Hops and Full-Duplex 47

2.5 Chapter Summary 48

2.6 Further Reading 48

2.7 Problems and Reflections 48

3 Access Beyond the Collision Model 53

3.1 Distance Gets into the Model 53

3.1.1 Communication Degrades as the Distance Increases 53

3.1.2 How to Make the Result of a Collision Dependent on the Distance 55

3.2 Simplified Distance Dependence: A Double Disk Model 57

3.3 Downlink Communication with the Double Disk Model 58

3.3.1 A Cautious Example of a Design that Reaches the Limits of the Model 61

3.4 Uplink Communication with the Double Disk Model 62

3.4.1 Uplink that Uses Multi-Packet Reception 64

3.4.2 Buffered Collisions for Future Use 64

3.4.3 Protocols that Use Packet Fractions 66

3.5 Unwrapping the Packets 68

3.6 Chapter Summary 69

3.7 Further Reading 70

3.8 Problems and Reflections 70

4 The Networking Cake: Layering and Slicing 75

4.1 Layering for a One-Way Link 75

4.1.1 Modules and their Interconnection 75

4.1.2 Three Important Concepts in Layering 77

4.1.3 An Example of a Two-Layer System 78

4.2 Layers and Cross-Layer 79

4.3 Reliable and Unreliable Service from a Layer 81

4.4 Black Box Functionality for Different Communication Models 84

4.5 Standard Layering Models 86

4.5.1 Connection versus Connectionless 87

4.5.2 Functionality of the Standard Layers 88

4.5.3 A Very Brief Look at the Network Layer 89

4.6 An Alternative Wireless Layering 91

4.7 Cross-Layer Design for Multiple Hops 92

4.8 Slicing of the Wireless Communication Resources 94

4.8.1 Analog, Digital, Sliced 94

4.8.2 A Primer on Wireless Slicing 96

4.8.2.1 Orthogonal Wireless Slicing 96

4.8.2.2 Non-Orthogonal Wireless Slicing 98

4.9 Chapter Summary 100

4.10 Further Reading 100

4.11 Problems and Reflections 100

5 Packets Under the Looking Glass: Symbols and Noise 105

5.1 Compression, Entropy, and Bit 105

5.1.1 Obtaining Digital Messages by Compression 106

5.1.2 A Bit of Information 106

5.2 Baseband Modules of the Communication System 107

5.2.1 Mapping Bits to Baseband Symbols under Simplifying Assumptions 108

5.2.2 Challenging the Simplifying Assumptions about the Baseband 109

5.3 Signal Constellations and Noise 110

5.3.1 Constellation Points and Noise Clouds 110

5.3.2 Constellations with Limited Average Power 113

5.3.3 Beyond the Simple Setup for Symbol Detection 114

5.3.4 Signal-to-Noise Ratio (SNR) 116

5.4 From Bits to Symbols 117

5.4.1 Binary Phase Shift Keying (BPSK) 117

5.4.2 Quaternary Phase Shift Keying (QPSK) 118

5.4.3 Constellations of Higher Order 119

5.4.4 Generalized Mapping to Many Symbols 122

5.5 Symbol-Level Interference Models 123

5.5.1 Advanced Treatment of Collisions based on a Baseband Model 124

5.6 Weak and Strong Signals: New Protocol Possibilities 126

5.6.1 Randomization of Power 127

5.6.2 Other Goodies from the Baseband Model 129

5.7 How to Select the Data Rate 130

5.7.1 A Simple Relation between Packet Errors and Distance 130

5.7.2 Adaptive Modulation 132

5.8 Superposition of Baseband Symbols 134

5.8.1 Broadcast and Non-Orthogonal Access 135

5.8.2 Unequal Error Protection (UEP) 137

5.9 Communication with Unknown Channel Coefficients 138

5.10 Chapter Summary 141

5.11 Further Reading 142

5.12 Problems and Reflections 142

6 A Mathematical View on a Communication Channel 147

6.1 A Toy Example: The Pigeon Communication Channel 147

6.1.1 Specification of a Communication Channel 149

6.1.2 Comparison of the Information Carrying Capability of Mathematical Channels 150

6.1.3 Assumptions and Notations 151

6.2 Analog Channels with Gaussian Noise 151

6.2.1 Gaussian Channel 152

6.2.2 Other Analog Channels Based on the Gaussian Channel 152

6.3 The Channel Definition Depends on Who Knows What 154

6.4 Using Analog to Create Digital Communication Channels 158

6.4.1 Creating Digital Channels through Gray Mapping 158

6.4.2 Creating Digital Channels through Superposition 161

6.5 Transmission of Packets over Communication Channels 163

6.5.1 Layering Perspective of the Communication Channels 163

6.5.2 How to Obtain Throughput that is not Zero 164

6.5.3 Asynchronous Packets and Transmission of "Nothing" 167

6.5.4 Packet Transmission over a Ternary Channel 169

6.6 Chapter Summary 171

6.7 Further Reading 171

6.8 Problems and Reflections 172

7 Coding for Reliable Communication 177

7.1 Some Coding Ideas for the Binary Symmetric Channel 177

7.1.1 A Channel Based on Repetition Coding 177

7.1.2 Channel Based on Repetition Coding with Erasures 179

7.1.3 Coding Beyond Repetition 181

7.1.4 An Illustrative Comparison of the BSC Based Channels 182

7.2 Generalization of the Coding Idea 183

7.2.1 Maximum Likelihood (ML) Decoding 187

7.3 Linear Block Codes for the Binary Symmetric Channel 188

7.4 Coded Modulation as a Layered Subsystem 192

7.5 Retransmission as a Supplement to Coding 194

7.5.1 Full Packet Retransmission 195

7.5.2 Partial Retransmission and Incremental Redundancy 197

7.6 Chapter Summary 199

7.7 Further Reading 199

7.8 Problems and Reflections 199

8 Information-Theoretic View on Wireless Channel Capacity 203

8.1 It Starts with the Law of Large Numbers 203

8.2 A Useful Digression into Source Coding 204

8.3 Perfectly Reliable Communication and Channel Capacity 207

8.4 Mutual Information and Its Interpretations 209

8.4.1 From a Local to a Global Property 209

8.4.2 Mutual Information in Some Actual Communication Setups 211

8.5 The Gaussian Channel and the Popular Capacity Formula 214

8.5.1 The Concept of Entropy in Analog Channels 214

8.5.2 The Meaning of "Shannon's Capacity Formula" 215

8.5.3 Simultaneous Usage of Multiple Gaussian Channels 217

8.6 Capacity of Fading Channels 219

8.6.1 Channel State Information Available at the Transmitter 219

8.6.2 Example: Water Filling for Binary Fading 221

8.6.3 Water Filling for Continuously Distributed Fading 222

8.6.4 Fast Fading and Further Remarks on Channel Knowledge 223

8.6.5 Capacity When the Transmitter Does Not Know the Channel 225

8.6.5.1 Channel with Binary Inputs and Binary Fading 225

8.6.5.2 Channels with Gaussian Noise and Fading 229

8.6.6 Channel Estimation and Knowledge 230

8.7 Chapter Summary 232

8.8 Further Reading 233

8.9 Problems and Reflections 233

9 Time and Frequency in Wireless Communications 237

9.1 Reliable Communication Requires Transmission of Discrete Values 237

9.2 Communication Through a Waveform: An Example 239

9.3 Enter the Frequency 242

9.3.1 Infinitely Long Signals and True Frequency 242

9.3.2 Bandwidth and Time-Limited Signals 245

9.3.3 Parallel Communication Channels 247

9.3.4 How Frequency Affects the Notion of Multiple Access 248

9.4 Noise and Interference 250

9.4.1 Signal Power and Gaussian White Noise 250

9.4.2 Interference between Non-Orthogonal Frequencies 252

9.5 Power Spectrum and Fourier Transform 255

9.6 Frequency Channels, Finally 258

9.6.1 Capacity of a Bandlimited Channel 259

9.6.2 Capacity and OFDM Transmission 261

9.6.3 Frequency for Multiple Access and Duplexing 261

9.7 Code Division and Spread Spectrum 263

9.7.1 Sharing Synchronized Resources with Orthogonal Codes 263

9.7.2 Why Go Through the Trouble of Spreading? 265

9.7.3 Mimicking the Noise and Covert Communication 268

9.7.4 Relation to Random Access 269

9.8 Chapter Summary 270

9.9 Further Reading 270

9.10 Problems and Reflections 270

10 Space in Wireless Communications 275

10.1 Communication Range and Coverage Area 276

10.2 The Myth about Frequencies that Propagate Badly in Free Space 278

10.3 The World View of an Antenna 280

10.3.1 Antenna Directivity 280

10.3.2 Directivity Changes the Communication Models 282

10.4 Multipath and Shadowing: Space is Rarely Free 283

10.5 The Final Missing Link in the Layering Model 286

10.6 The Time-Frequency Dynamics of the Radio Channel 288

10.6.1 How a Time-Invariant Channel Distorts the Received Signal 288

10.6.2 Frequency Selectivity, Multiplexing, and Diversity 291

10.6.3 Time-Variant Channel Introduces New Frequencies 292

10.6.4 Combined Time-Frequency Dynamics 295

10.7 Two Ideas to Deal with Multipath Propagation and Delay Spread 296

10.7.1 The Wideband Idea: Spread Spectrum and a RAKE Receiver 297

10.7.2 The Narrowband Idea: OFDM and a Guard Interval 299

10.8 Statistical Modeling of Wireless Channels 300

10.8.1 Fading Models: Rayleigh and Some Others 301

10.8.2 Randomness in the Path Loss 303

10.9 Reciprocity and How to Use It 303

10.10 Chapter Summary 305

10.11 Further Reading 305

10.12 Problems and Reflections 305

11 Using Two,...
Details
Erscheinungsjahr: 2020
Fachbereich: Nachrichtentechnik
Genre: Technik
Rubrik: Naturwissenschaften & Technik
Medium: Buch
Seiten: 416
Inhalt: 408 S.
ISBN-13: 9780470683996
ISBN-10: 0470683996
Sprache: Englisch
Herstellernummer: 14568399000
Einband: Gebunden
Autor: Popovski, Petar
Hersteller: Wiley
Maße: 251 x 176 x 27 mm
Von/Mit: Petar Popovski
Erscheinungsdatum: 04.05.2020
Gewicht: 0,854 kg
preigu-id: 117907548
Über den Autor

Petar Popovski is a Professor of Wireless Communications at Aalborg University and Fellow of the IEEE. He received his Dipl.-Ing and M. Sc. degrees in Communication Engineering from the University of Sts. Cyril and Methodius in Skopje and the Ph.D. degree from Aalborg University in 2005. He has over 300 publications in journals, conference proceedings, and edited books. He holds over 30 patents and patent applications. He received an ERC Consolidator Grant (2015), the Danish Elite Researcher award (2016), IEEE Fred W. Ellersick prize (2016), and IEEE Stephen O. Rice prize (2018). He is featured in the list of Highly Cited Researchers 2018, compiled by Web of Science. His research interests are in the area of wireless communication and communication theory.

Inhaltsverzeichnis
Foreword xv

Acknowledgments xix

Acronyms xxi

1 An Easy Introduction to the Shared Wireless Medium 3

1.1 How to Build a Simple Model for Wireless Communication 4

1.1.1 Which Features We Want from the Model 4

1.1.2 Communication Channel with Collisions 4

1.1.3 Trade-offs in the Collision Model 7

1.2 The First Contact 9

1.2.1 Hierarchy Helps to Establish Contact 9

1.2.2 Wireless Rendezvous without Help 11

1.2.3 Rendezvous with Full-Duplex Devices 12

1.3 Multiple Access with Centralized Control 12

1.3.1 A Frame for Time Division 13

1.3.2 Frame Header for Flexible Time Division 14

1.3.3 A Simple Two-Way System that Works Under the Collision Model 15

1.3.4 Still Not a Practical TDMA System 18

1.4 Making TDMA Dynamic 19

1.4.1 Circuit-Switched versus Packet-Switched Operation 19

1.4.2 Dynamic Allocation of Resources to Users 20

1.4.3 Short Control Packets and the Idea of Reservation 22

1.4.4 Half-Duplex versus Full-Duplex in TDMA 24

1.5 Chapter Summary 25

1.6 Further Reading 25

1.7 Problems and Reflections 26

2 Random Access: How to Talk in Crowded Dark Room 29

2.1 Framed ALOHA 30

2.1.1 Randomization that Maximizes the ALOHA Throughput 32

2.2 Probing 35

2.2.1 Combining ALOHA and Probing 39

2.3 Carrier Sensing 39

2.3.1 Randomization and Spectrum Sharing 39

2.3.2 An Idle Slot is Cheap 41

2.3.3 Feedback to the Transmitter 43

2.4 Random Access and Multiple Hops 45

2.4.1 Use of Reservation Packets in Multi-Hop 47

2.4.2 Multiple Hops and Full-Duplex 47

2.5 Chapter Summary 48

2.6 Further Reading 48

2.7 Problems and Reflections 48

3 Access Beyond the Collision Model 53

3.1 Distance Gets into the Model 53

3.1.1 Communication Degrades as the Distance Increases 53

3.1.2 How to Make the Result of a Collision Dependent on the Distance 55

3.2 Simplified Distance Dependence: A Double Disk Model 57

3.3 Downlink Communication with the Double Disk Model 58

3.3.1 A Cautious Example of a Design that Reaches the Limits of the Model 61

3.4 Uplink Communication with the Double Disk Model 62

3.4.1 Uplink that Uses Multi-Packet Reception 64

3.4.2 Buffered Collisions for Future Use 64

3.4.3 Protocols that Use Packet Fractions 66

3.5 Unwrapping the Packets 68

3.6 Chapter Summary 69

3.7 Further Reading 70

3.8 Problems and Reflections 70

4 The Networking Cake: Layering and Slicing 75

4.1 Layering for a One-Way Link 75

4.1.1 Modules and their Interconnection 75

4.1.2 Three Important Concepts in Layering 77

4.1.3 An Example of a Two-Layer System 78

4.2 Layers and Cross-Layer 79

4.3 Reliable and Unreliable Service from a Layer 81

4.4 Black Box Functionality for Different Communication Models 84

4.5 Standard Layering Models 86

4.5.1 Connection versus Connectionless 87

4.5.2 Functionality of the Standard Layers 88

4.5.3 A Very Brief Look at the Network Layer 89

4.6 An Alternative Wireless Layering 91

4.7 Cross-Layer Design for Multiple Hops 92

4.8 Slicing of the Wireless Communication Resources 94

4.8.1 Analog, Digital, Sliced 94

4.8.2 A Primer on Wireless Slicing 96

4.8.2.1 Orthogonal Wireless Slicing 96

4.8.2.2 Non-Orthogonal Wireless Slicing 98

4.9 Chapter Summary 100

4.10 Further Reading 100

4.11 Problems and Reflections 100

5 Packets Under the Looking Glass: Symbols and Noise 105

5.1 Compression, Entropy, and Bit 105

5.1.1 Obtaining Digital Messages by Compression 106

5.1.2 A Bit of Information 106

5.2 Baseband Modules of the Communication System 107

5.2.1 Mapping Bits to Baseband Symbols under Simplifying Assumptions 108

5.2.2 Challenging the Simplifying Assumptions about the Baseband 109

5.3 Signal Constellations and Noise 110

5.3.1 Constellation Points and Noise Clouds 110

5.3.2 Constellations with Limited Average Power 113

5.3.3 Beyond the Simple Setup for Symbol Detection 114

5.3.4 Signal-to-Noise Ratio (SNR) 116

5.4 From Bits to Symbols 117

5.4.1 Binary Phase Shift Keying (BPSK) 117

5.4.2 Quaternary Phase Shift Keying (QPSK) 118

5.4.3 Constellations of Higher Order 119

5.4.4 Generalized Mapping to Many Symbols 122

5.5 Symbol-Level Interference Models 123

5.5.1 Advanced Treatment of Collisions based on a Baseband Model 124

5.6 Weak and Strong Signals: New Protocol Possibilities 126

5.6.1 Randomization of Power 127

5.6.2 Other Goodies from the Baseband Model 129

5.7 How to Select the Data Rate 130

5.7.1 A Simple Relation between Packet Errors and Distance 130

5.7.2 Adaptive Modulation 132

5.8 Superposition of Baseband Symbols 134

5.8.1 Broadcast and Non-Orthogonal Access 135

5.8.2 Unequal Error Protection (UEP) 137

5.9 Communication with Unknown Channel Coefficients 138

5.10 Chapter Summary 141

5.11 Further Reading 142

5.12 Problems and Reflections 142

6 A Mathematical View on a Communication Channel 147

6.1 A Toy Example: The Pigeon Communication Channel 147

6.1.1 Specification of a Communication Channel 149

6.1.2 Comparison of the Information Carrying Capability of Mathematical Channels 150

6.1.3 Assumptions and Notations 151

6.2 Analog Channels with Gaussian Noise 151

6.2.1 Gaussian Channel 152

6.2.2 Other Analog Channels Based on the Gaussian Channel 152

6.3 The Channel Definition Depends on Who Knows What 154

6.4 Using Analog to Create Digital Communication Channels 158

6.4.1 Creating Digital Channels through Gray Mapping 158

6.4.2 Creating Digital Channels through Superposition 161

6.5 Transmission of Packets over Communication Channels 163

6.5.1 Layering Perspective of the Communication Channels 163

6.5.2 How to Obtain Throughput that is not Zero 164

6.5.3 Asynchronous Packets and Transmission of "Nothing" 167

6.5.4 Packet Transmission over a Ternary Channel 169

6.6 Chapter Summary 171

6.7 Further Reading 171

6.8 Problems and Reflections 172

7 Coding for Reliable Communication 177

7.1 Some Coding Ideas for the Binary Symmetric Channel 177

7.1.1 A Channel Based on Repetition Coding 177

7.1.2 Channel Based on Repetition Coding with Erasures 179

7.1.3 Coding Beyond Repetition 181

7.1.4 An Illustrative Comparison of the BSC Based Channels 182

7.2 Generalization of the Coding Idea 183

7.2.1 Maximum Likelihood (ML) Decoding 187

7.3 Linear Block Codes for the Binary Symmetric Channel 188

7.4 Coded Modulation as a Layered Subsystem 192

7.5 Retransmission as a Supplement to Coding 194

7.5.1 Full Packet Retransmission 195

7.5.2 Partial Retransmission and Incremental Redundancy 197

7.6 Chapter Summary 199

7.7 Further Reading 199

7.8 Problems and Reflections 199

8 Information-Theoretic View on Wireless Channel Capacity 203

8.1 It Starts with the Law of Large Numbers 203

8.2 A Useful Digression into Source Coding 204

8.3 Perfectly Reliable Communication and Channel Capacity 207

8.4 Mutual Information and Its Interpretations 209

8.4.1 From a Local to a Global Property 209

8.4.2 Mutual Information in Some Actual Communication Setups 211

8.5 The Gaussian Channel and the Popular Capacity Formula 214

8.5.1 The Concept of Entropy in Analog Channels 214

8.5.2 The Meaning of "Shannon's Capacity Formula" 215

8.5.3 Simultaneous Usage of Multiple Gaussian Channels 217

8.6 Capacity of Fading Channels 219

8.6.1 Channel State Information Available at the Transmitter 219

8.6.2 Example: Water Filling for Binary Fading 221

8.6.3 Water Filling for Continuously Distributed Fading 222

8.6.4 Fast Fading and Further Remarks on Channel Knowledge 223

8.6.5 Capacity When the Transmitter Does Not Know the Channel 225

8.6.5.1 Channel with Binary Inputs and Binary Fading 225

8.6.5.2 Channels with Gaussian Noise and Fading 229

8.6.6 Channel Estimation and Knowledge 230

8.7 Chapter Summary 232

8.8 Further Reading 233

8.9 Problems and Reflections 233

9 Time and Frequency in Wireless Communications 237

9.1 Reliable Communication Requires Transmission of Discrete Values 237

9.2 Communication Through a Waveform: An Example 239

9.3 Enter the Frequency 242

9.3.1 Infinitely Long Signals and True Frequency 242

9.3.2 Bandwidth and Time-Limited Signals 245

9.3.3 Parallel Communication Channels 247

9.3.4 How Frequency Affects the Notion of Multiple Access 248

9.4 Noise and Interference 250

9.4.1 Signal Power and Gaussian White Noise 250

9.4.2 Interference between Non-Orthogonal Frequencies 252

9.5 Power Spectrum and Fourier Transform 255

9.6 Frequency Channels, Finally 258

9.6.1 Capacity of a Bandlimited Channel 259

9.6.2 Capacity and OFDM Transmission 261

9.6.3 Frequency for Multiple Access and Duplexing 261

9.7 Code Division and Spread Spectrum 263

9.7.1 Sharing Synchronized Resources with Orthogonal Codes 263

9.7.2 Why Go Through the Trouble of Spreading? 265

9.7.3 Mimicking the Noise and Covert Communication 268

9.7.4 Relation to Random Access 269

9.8 Chapter Summary 270

9.9 Further Reading 270

9.10 Problems and Reflections 270

10 Space in Wireless Communications 275

10.1 Communication Range and Coverage Area 276

10.2 The Myth about Frequencies that Propagate Badly in Free Space 278

10.3 The World View of an Antenna 280

10.3.1 Antenna Directivity 280

10.3.2 Directivity Changes the Communication Models 282

10.4 Multipath and Shadowing: Space is Rarely Free 283

10.5 The Final Missing Link in the Layering Model 286

10.6 The Time-Frequency Dynamics of the Radio Channel 288

10.6.1 How a Time-Invariant Channel Distorts the Received Signal 288

10.6.2 Frequency Selectivity, Multiplexing, and Diversity 291

10.6.3 Time-Variant Channel Introduces New Frequencies 292

10.6.4 Combined Time-Frequency Dynamics 295

10.7 Two Ideas to Deal with Multipath Propagation and Delay Spread 296

10.7.1 The Wideband Idea: Spread Spectrum and a RAKE Receiver 297

10.7.2 The Narrowband Idea: OFDM and a Guard Interval 299

10.8 Statistical Modeling of Wireless Channels 300

10.8.1 Fading Models: Rayleigh and Some Others 301

10.8.2 Randomness in the Path Loss 303

10.9 Reciprocity and How to Use It 303

10.10 Chapter Summary 305

10.11 Further Reading 305

10.12 Problems and Reflections 305

11 Using Two,...
Details
Erscheinungsjahr: 2020
Fachbereich: Nachrichtentechnik
Genre: Technik
Rubrik: Naturwissenschaften & Technik
Medium: Buch
Seiten: 416
Inhalt: 408 S.
ISBN-13: 9780470683996
ISBN-10: 0470683996
Sprache: Englisch
Herstellernummer: 14568399000
Einband: Gebunden
Autor: Popovski, Petar
Hersteller: Wiley
Maße: 251 x 176 x 27 mm
Von/Mit: Petar Popovski
Erscheinungsdatum: 04.05.2020
Gewicht: 0,854 kg
preigu-id: 117907548
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