Underwater Electric Field Communication

Abstract

Underwater communications receive more attention with rising need for autonomous underwater vehicles (AUV) and underwater infrastructure. Numerous applications e.g. video streams often require only a short-range wireless transmission up to several meters in seawater with high data rates up to several megabit per second. Radio transmission in high frequency band offers high data rates but due to extreme attenuation the range is limited to less than one meter. Therefore, we suggest to set up an electrical field by two electrodes forming a dipole for transmission and reception in the MF Band (medium frequency band between 100 kHz and 10 MHz). Analytic calculations and simulations verify the concept. In the second step, we measure the transmission channel with different transmitter and receiver geometries. We show that the achievable transmission range of our approach is scalable with the separation distance between the electrodes. In a first practical evaluation with software defined radios we realized a communication link with digital modulation and a data rate of two megabit per second with signal frequency of 2 MHz for several meters.