High-Data Rate Carrierless Impulsive Communications For Underwater Acoustic Networks

Underwater networks of wireless sensors deployed along the coast or in the deep water are the most promising solution for the development of underwater monitoring, exploration and surveillance applications. A key feature of underwater networks that can significantly enhance current monitoring applications, is the ability to support sufficiently high data rates that can accommodate real-time video information on an underwater communication link. Unfortunately, the intrinsic characteristic of the underwater propagation medium have made this objective extremely challenging. In this paper, we present the first physical layer transmission scheme for short-range and high-data rate ultrasonic underwater communications. The proposed solution, which we will refer to as Underwater UltraComm (U2C), is based on the idea of transmitting short information-bearing carrierless ultrasonic signals, e.g., pulses, following a pseudo-random adaptive time-hopping pattern with a superimposed rate-adaptive Reed-Solomon forward error correction (FEC) channel coding. We extensively evaluate the U2C performance through water tank experiments. Results show that U2C links can support point-to-point data rate up to 1.38 Mbps, and that by leveraging the flexibility of the adaptive time-hopping and adaptive channel coding techniques, one can trade between link throughput energy consumption.