Acoustic communication

Abstract

In this chapter, we discuss acoustic communication methods which are used to provide wireless connection between remote nodes operating in an underwater environment. We begin with an introductory overview of the history of acoustic communication, and an outline of current and emerging applications. We then provide a summary of communication channel characteristics, with an eye towards acoustic propagation mechanisms and the ways in which they differ from radio propagation. The main focus of our treatment is on two major aspects of communication system design: the physical link and the networking functions. On the physical link level, we discuss noncoherent and coherent modulation/detection methods, paying attention to both single-carrier modulation and multicarrier broadband techniques. Specifically, we discuss signal processing methods for synchronization, equalization, and multichannel (transmit and receive) combining. On the networking level, we discuss protocols for channel sharing using both deterministic division of resources (frequency, time, and code-division multiple access) and random access, and we also overview recent results on routing for peer-to-peer acoustic networks. We conclude with an outline of topics for future research.