Оглавление
Petar Popovski. Wireless Connectivity
Table of Contents
List of Tables
List of Illustrations
Guide
Pages
Wireless Connectivity. An Intuitive and Fundamental Guide
Foreword
Acknowledgments
Acronyms
1 An Easy Introduction to the Shared Wireless Medium
1.1 How to Build a Simple Model for Wireless Communication. 1.1.1 Which Features We Want from the Model
1.1.2 Communication Channel with Collisions
1.1.3 Trade-offs in the Collision Model
1.2 The First Contact
1.2.1 Hierarchy Helps to Establish Contact
1.2.2 Wireless Rendezvous without Help
1.2.3 Rendezvous with Full-Duplex Devices
1.3 Multiple Access with Centralized Control
1.3.1 A Frame for Time Division
1.3.2 Frame Header for Flexible Time Division
1.3.3 A Simple Two-Way System that Works Under the Collision Model
1.3.4 Still Not a Practical TDMA System
1.4 Making TDMA Dynamic. 1.4.1 Circuit-Switched versus Packet-Switched Operation
1.4.2 Dynamic Allocation of Resources to Users
1.4.3 Short Control Packets and the Idea of Reservation
1.4.4 Half-Duplex versus Full-Duplex in TDMA
1.5 Chapter Summary
1.6 Further Reading
1.7 Problems and Reflections
Notes
2 Random Access: How to Talk in Crowded Dark Room
2.1 Framed ALOHA
2.1.1 Randomization that Maximizes the ALOHA Throughput
2.2 Probing
2.2.1 Combining ALOHA and Probing
2.3 Carrier Sensing. 2.3.1 Randomization and Spectrum Sharing
2.3.2 An Idle Slot is Cheap
2.3.3 Feedback to the Transmitter
2.4 Random Access and Multiple Hops
2.4.1 Use of Reservation Packets in Multi-Hop
2.4.2 Multiple Hops and Full-Duplex
2.5 Chapter Summary
2.6 Further Reading
2.7 Problems and Reflections
Note
3 Access Beyond the Collision Model
3.1 Distance Gets into the Model. 3.1.1 Communication Degrades as the Distance Increases
3.1.2 How to Make the Result of a Collision Dependent on the Distance
3.2 Simplified Distance Dependence: A Double Disk Model
3.3 Downlink Communication with the Double Disk Model
3.3.1 A Cautious Example of a Design that Reaches the Limits of the Model
3.4 Uplink Communication with the Double Disk Model
3.4.1 Uplink that Uses Multi-Packet Reception
3.4.2 Buffered Collisions for Future Use
3.4.3 Protocols that Use Packet Fractions
3.5 Unwrapping the Packets
3.6 Chapter Summary
3.7 Further Reading
3.8 Problems and Reflections
Notes
4 The Networking Cake: Layering and Slicing
4.1 Layering for a One-Way Link. 4.1.1 Modules and their Interconnection
4.1.2 Three Important Concepts in Layering
4.1.3 An Example of a Two-Layer System
4.2 Layers and Cross-Layer
4.3 Reliable and Unreliable Service from a Layer
4.4 Black Box Functionality for Different Communication Models
4.5 Standard Layering Models
4.5.1 Connection versus Connectionless
4.5.2 Functionality of the Standard Layers
4.5.3 A Very Brief Look at the Network Layer
4.6 An Alternative Wireless Layering
4.7 Cross-Layer Design for Multiple Hops
4.8 Slicing of the Wireless Communication Resources
4.8.1 Analog, Digital, Sliced
4.8.2 A Primer on Wireless Slicing
4.8.2.1 Orthogonal Wireless Slicing
4.8.2.2 Non-Orthogonal Wireless Slicing
4.9 Chapter Summary
4.10 Further Reading
4.11 Problems and Reflections
Notes
5 Packets Under the Looking Glass: Symbols and Noise
5.1 Compression, Entropy, and Bit
5.1.1 Obtaining Digital Messages by Compression
5.1.2 A Bit of Information
5.2 Baseband Modules of the Communication System
5.2.1 Mapping Bits to Baseband Symbols under Simplifying Assumptions
5.2.2 Challenging the Simplifying Assumptions about the Baseband
5.3 Signal Constellations and Noise. 5.3.1 Constellation Points and Noise Clouds
5.3.2 Constellations with Limited Average Power
5.3.3 Beyond the Simple Setup for Symbol Detection
5.3.4 Signal-to-Noise Ratio (SNR)
5.4 From Bits to Symbols. 5.4.1 Binary Phase Shift Keying (BPSK)
5.4.2 Quaternary Phase Shift Keying (QPSK)
5.4.3 Constellations of Higher Order
5.4.4 Generalized Mapping to Many Symbols
5.5 Symbol-Level Interference Models
5.5.1 Advanced Treatment of Collisions based on a Baseband Model
5.6 Weak and Strong Signals: New Protocol Possibilities
5.6.1 Randomization of Power
5.6.2 Other Goodies from the Baseband Model
5.7 How to Select the Data Rate
5.7.1 A Simple Relation between Packet Errors and Distance
5.7.2 Adaptive Modulation
5.8 Superposition of Baseband Symbols
5.8.1 Broadcast and Non-Orthogonal Access
5.8.2 Unequal Error Protection (UEP)
5.9 Communication with Unknown Channel Coefficients
5.10 Chapter Summary
5.11 Further Reading
5.12 Problems and Reflections
Notes
6 A Mathematical View on a Communication Channel
6.1 A Toy Example: The Pigeon Communication Channel
6.1.1 Specification of a Communication Channel
6.1.2 Comparison of the Information Carrying Capability of Mathematical Channels
6.1.3 Assumptions and Notations
6.2 Analog Channels with Gaussian Noise
6.2.1 Gaussian Channel
6.2.2 Other Analog Channels Based on the Gaussian Channel
6.3 The Channel Definition Depends on Who Knows What
6.4 Using Analog to Create Digital Communication Channels
6.4.1 Creating Digital Channels through Gray Mapping
6.4.2 Creating Digital Channels through Superposition
6.5 Transmission of Packets over Communication Channels
6.5.1 Layering Perspective of the Communication Channels
6.5.2 How to Obtain Throughput that is not Zero
6.5.3 Asynchronous Packets and Transmission of “Nothing”
6.5.4 Packet Transmission over a Ternary Channel
6.6 Chapter Summary
6.7 Further Reading
6.8 Problems and Reflections
Note
7 Coding for Reliable Communication
7.1 Some Coding Ideas for the Binary Symmetric Channel. 7.1.1 A Channel Based on Repetition Coding
7.1.2 Channel Based on Repetition Coding with Erasures
7.1.3 Coding Beyond Repetition
7.1.4 An Illustrative Comparison of the BSC Based Channels
7.2 Generalization of the Coding Idea
7.2.1 Maximum Likelihood (ML) Decoding
7.3 Linear Block Codes for the Binary Symmetric Channel
7.4 Coded Modulation as a Layered Subsystem
7.5 Retransmission as a Supplement to Coding
7.5.1 Full Packet Retransmission
7.5.2 Partial Retransmission and Incremental Redundancy
7.6 Chapter Summary
7.7 Further Reading
7.8 Problems and Reflections
Notes
8 Information-Theoretic View on Wireless Channel Capacity
8.1 It Starts with the Law of Large Numbers
8.2 A Useful Digression into Source Coding
8.3 Perfectly Reliable Communication and Channel Capacity
8.4 Mutual Information and Its Interpretations. 8.4.1 From a Local to a Global Property
8.4.2 Mutual Information in Some Actual Communication Setups
8.5 The Gaussian Channel and the Popular Capacity Formula. 8.5.1 The Concept of Entropy in Analog Channels
8.5.2 The Meaning of “Shannon's Capacity Formula”
8.5.3 Simultaneous Usage of Multiple Gaussian Channels
8.6 Capacity of Fading Channels
8.6.1 Channel State Information Available at the Transmitter
8.6.2 Example: Water Filling for Binary Fading
8.6.3 Water Filling for Continuously Distributed Fading
8.6.4 Fast Fading and Further Remarks on Channel Knowledge
8.6.5 Capacity When the Transmitter Does Not Know the Channel
8.6.5.1 Channel with Binary Inputs and Binary Fading
8.6.5.2 Channels with Gaussian Noise and Fading
8.6.6 Channel Estimation and Knowledge
8.7 Chapter Summary
8.8 Further Reading
8.9 Problems and Reflections
Notes
9 Time and Frequency in Wireless Communications
9.1 Reliable Communication Requires Transmission of Discrete Values
9.2 Communication Through a Waveform: An Example
9.3 Enter the Frequency
9.3.1 Infinitely Long Signals and True Frequency
9.3.2 Bandwidth and Time-Limited Signals
9.3.3 Parallel Communication Channels
9.3.4 How Frequency Affects the Notion of Multiple Access
9.4 Noise and Interference
9.4.1 Signal Power and Gaussian White Noise
9.4.2 Interference between Non-Orthogonal Frequencies
9.5 Power Spectrum and Fourier Transform
9.6 Frequency Channels, Finally
9.6.1 Capacity of a Bandlimited Channel
9.6.2 Capacity and OFDM Transmission
9.6.3 Frequency for Multiple Access and Duplexing
9.7 Code Division and Spread Spectrum. 9.7.1 Sharing Synchronized Resources with Orthogonal Codes
9.7.2 Why Go Through the Trouble of Spreading?
9.7.3 Mimicking the Noise and Covert Communication
9.7.4 Relation to Random Access
9.8 Chapter Summary
9.9 Further Reading
9.10 Problems and Reflections
Notes
10 Space in Wireless Communications
10.1 Communication Range and Coverage Area
10.2 The Myth about Frequencies that Propagate Badly in Free Space
10.3 The World View of an Antenna. 10.3.1 Antenna Directivity
10.3.2 Directivity Changes the Communication Models
10.4 Multipath and Shadowing: Space is Rarely Free
10.5 The Final Missing Link in the Layering Model
10.6 The Time-Frequency Dynamics of the Radio Channel
10.6.1 How a Time-Invariant Channel Distorts the Received Signal
10.6.2 Frequency Selectivity, Multiplexing, and Diversity
10.6.3 Time-Variant Channel Introduces New Frequencies
10.6.4 Combined Time-Frequency Dynamics
10.7 Two Ideas to Deal with Multipath Propagation and Delay Spread
10.7.1 The Wideband Idea: Spread Spectrum and a RAKE Receiver
10.7.2 The Narrowband Idea: OFDM and a Guard Interval
10.8 Statistical Modeling of Wireless Channels
10.8.1 Fading Models: Rayleigh and Some Others
10.8.2 Randomness in the Path Loss
10.9 Reciprocity and How to Use It
10.10 Chapter Summary
10.11 Further Reading
10.12 Problems and Reflections
Notes
11 Using Two, More, or a Massive Number of Antennas
11.1 Assumptions about the Channel Model and the Antennas
11.2 Receiving or Transmitting with a Two-Antenna Device
11.2.1 Receiver with Two Antennas
11.2.2 Using Two Antennas at a Knowledgeable Transmitter
11.2.3 Transmit Diversity
11.3 Introducing MIMO
11.3.1 Spatial Multiplexing
11.4 Multiple Antennas for Spatial Division of Multiple Users
11.4.1 Digital Interference-Free Beams: Zero Forcing
11.4.2 Other Schemes for Precoding and Digital Beamforming
11.5 Beamforming and Spectrum Sharing
11.6 What If the Number of Antennas is Scaled Massively?
11.6.1 The Base Station Knows the Channels Perfectly
11.6.2 The Base Station has to Learn the Channels
11.7 Chapter Summary
11.8 Further Reading
11.9 Problems and Reflections
Notes
12 Wireless Beyond a Link: Connections and Networks
12.1 Wireless Connections with Different Flavors. 12.1.1 Coarse Classification of the Wireless Connections
12.1.2 The Complex, Multidimensional World of Wireless Connectivity
12.2 Fundamental Ideas for Providing Wireless Coverage
12.2.1 Static or Moving Infrastructure
12.2.2 Cells and a Cellular Network
12.2.3 Spatial Reuse
12.2.4 Cells Come in Different Sizes
12.2.5 Two-Way Coverage and Decoupled Access
12.3 No Cell is an Island
12.3.1 Wired and Wireless Backhaul
12.3.2 Wireless One-Way Relaying and the Half-Duplex Loss
12.3.3 Wireless Two-Way Relaying: Reclaiming the Half-Duplex Loss
12.4 Cooperation and Coordination
12.4.1 Artificial Multipath: Treating the BS as Yet Another Antenna
12.4.2 Distributing and Networking the MIMO Concept
12.4.3 Cooperation Through a Wireless Backhaul
12.5 Dissolving the Cells into Clouds and Fog. 12.5.1 The Unattainable Ideal Coverage
12.5.2 The Backhaul Links Must Have a Finite Capacity
12.5.3 Noisy Cooperation with a Finite Backhaul
12.5.4 Access Through Clouds and Fog
12.6 Coping with External Interference and Other Questions about the Radio Spectrum. 12.6.1 Oblivious Rather Than Selfish
12.6.2 License to Control Interference
12.6.3 Spectrum Sharing and Caring
12.6.4 Duty Cycling, Sensing, and Hopping
12.6.5 Beyond the Licensed and Unlicensed and Some Final Words
12.7 Chapter Summary
12.8 Further Reading
12.9 Problems and Reflections
Notes
Bibliography
Index
WILEY END USER LICENSE AGREEMENT
