Digital Underwater Acoustic Communications-水声数字通信

Chapter 1
Introduction
1．1 Overview of Underwater Acoustic Communication Development
1．2 Peculiarities of Underwater Acoustic Communication Channels Relative to Radio Communication Channels
1．3 Explorations Establishing an Innovative Digital Underwater Acoustic Communication Signal Processing System
1．3．1 Digital Underwater Acoustic Communications
1．3．2 Main Civil Digital Underwater Acoustic Communication Systems at Present
1．3．3 Explorations Establishing Innovative Digital Underwater Acoustic Communication System
1．4 Communication Sonar Equation

Chapter 2
Underwater Acoustic Communication Channels
2．1 Theatrical Methods of Underwater Acoustic Fields
2．1．1 Wave Equation and Conditions for Determining Solution
2．1．2 Theory of Ray Acoustics
2．2 Sound Transmission Loss in the Sea
2．2．1 Sound Fields in Layered Inhomogeneous Media
2．2．2 Transmission Loss Due to Sound Absorption in the Seawater
2．2．3 Impacts of Sound Transmission Loss on Digital Underwater Acoustic Communications and Possible Countermeasures
2．3 Multipath Effects in Underwater Acoustic Communication channels
2．3．1 The Solutions of the Normal Mode with Respect to Sound Propagations in Two Layer Media
2．3．2 Expression of Virtual Source Images Jor Sound Propagations in Layered Media
2．3．3 Experimental Researches on Multipath Structures in Underwater Acoustic Communication Channels
2．3．4 Impacts of Multipath Effects on Digital Underwater Acoustic Communications and the Possible Countermeasures to Adapt to the Effects
2．4 Fluctuation of Transmitted Sound in Underwater Acoustic
Communication Channels
2．4．1 Fluctuation of Transmitted Sound Caused by the Random Inhomogeneity in the Body of the Seawater
2．4．2 Sound Scattering form Random Boundaries and the Fluctuation of Transmitted Sound in Underwater Acoustic Communication Channels
2．4．3 Impacts of the Fluctuation of Transmitted Sound on Digital Underwater Acoustic Communications and the Possible Countermeasures to Adapt to the Fluctuation
2．5 Noise in the Sea
2．5．1 Wave Equation with Sources in Fluid Medium
2．5．2 Ambient Noise in the Sea
2．5．3 Self-noise of Ships
2．5．4 Impacts of Background Noise in the Sea on Digital Underwater Acoustic Communications and the Countermeasures to Combat Against the Noise

Chapter 3
Digital Underwater Acoustic Communication
Signal Processing
3．1 Some Signal Processing Techniques in Radio Communications That Are Possible to Be Extended to Underwater Acoustic Communications
3．1．1 Optimum Linear Filter
3．1．2 Adaptive Filter and its Applications
3．1．3 Diversity Techniques for Fading Channels
3．1．4 Spread-Spectrum Technique
3．2 Some Digital Underwater Acoustic Communication Systems
3．2．1 MFSK System
3．2．2 The Applications of Spread Spectrum Systems on Digital Underwater Acoustic Communications
3．2．3 Underwater Acoustic Communication Channels and Optimum Linear Filters
3．3 Explorations to For Innovative Digital Underwater Acoustic Communication Signal Processing System
3．3．1 Several Core Techniques Requiring to be Solved in Civil Underwater Acoustic Communications
3．3．2 Principles Establishing an Innovative Civil Digital Underwater Acoustic Communication Signal Processing System
3．3．3 Innovation APNFM Digital Underwater Acoustic Communication Signal Processing System

Chapter 4
Digital Underwater Acoustic Communication
Equipments
4．1 Brief Introduction to Underwater Acoustic Transducers Employed in Underwater Acoustic Communication Equipments
4．1．1 Some Specific Requirements for Underwater Acoustic Communication Transducers
4．1．2 Tubular Ceramic Piezoelectric Transducer
4．2 Underwater Acoustic Telecontrol Communications by Using Digital Time Correlation Accumulation Decision Signal Processing Systems
4．2．1 Empirical Researches on the Physical Characteristics of Shallow Water Acoustic Channels
4．2．2 Development of Underwater Acoustic Telecontrol Instruction Communication Employed in the Underwater Acoustic Releaser
4．3 Development of Advanced FH-SS System Digital Multimedia Underwater Acoustic Communication Equipments
4．3．1 Expected Target
4．3．2 Chiefly Key Techniques
4．3．3 Experimental Explorations Jor Advanced FH System Digital Underwater Acoustic Data Communication Prototype
4．3．4 Analyses of Feasibility Extending the Prototype to Underwater Acoustic Multimedia Communications
4．4 Explorations Developing Innovative APNFM System Digital Underwater Acoustic Communication Equipments
4．4．1 Outline of the Overall Structure and Operating Processes Jor the APNFM System
4．4．2 Experimental Explorations of lnnovative APNFM System Digital Underwater Acoustic Communication Equipments

Appendix
Ultrasonic Sensing Systems in the Air Medium