OFDM in Deep Water Horizontal Communications

This chapter focuses on two scenarios where the channel consists of long separately clusters, leading to an extremely large delay spread – on the order of seconds: deep‐water horizontal channel and underwater broadcasting networking. It is devoted to designing orthogonal frequency‐division multiplexing (OFDM) receiver processing algorithms to address both interblock interference (IBI) and possible ICI in the received signal. The chapter describes a decision‐feedback based equalizer and a factor‐graph based equalizer, respectively, for joint IBI and ICI equalization. It presents an iterative block‐to‐block receiver, where all the received blocks within one batch of transmission are decoded jointly.The chapter presentsdiscusses the performance results using both simulation and experimental data sets collected from the Atlantic Undersea Test and Evaluation Center (AUTEC) network. It demonstrates the application of the receiver developed for the deep water horizontal channel to an underwater broadcasting network, and shows emulated experimental results.