Underwater acoustic communications are a rapidly growing field of research and
engineering, driven by the expansion of applications which require underwater data
transmission without wired connections. In this chapter, we explore the problems of
underwater acoustic communications in three parts. The first part presents an overview of
modern applications in underwater data transmission and today's achievements in this area.
System requirements are reviewed, and propagation characteristics of underwater acoustic …

Due to multipath propagation and frequency selective fading, there are many obstacles for
reliable and high data rate underwater acoustic (UWA) communication. OFDM is an
attractive technique beginning used in UWA communication with three obvious advantages:
good performance against multipath interference, ability to combat the frequency selective
fading and the high frequency band efficiency. Recently, the researches of Refs. 1, 2, 3, 4, 5
focus on short-range UWA communication. In this paper, we pay attention to medium-range …