Channel Modeling of MI Underwater Communication Using Tri-Directional Coil Antenna

Abstract

While underwater wireless communications have been investigated and implemented for decades, existing solutions still have difficulties in establishing reliable and low-delay wireless underwater links among small-size devices. The Magnetic Induction (MI) communication technique is among the promising solutions due to its advantages in low propagation delay and less susceptibility to the transmission environments. To date, existing MI models cannot accurately characterize the complex underwater MI channels, especially in the shallow water with omnidirectional antennas. In this paper, an analytical channel model is developed for underwater MI communication system with Tri-directional coil (TD coil), which is derived based on the rigorous electromagnetic field analysis. The MIMO channel between the tri-directional coil antennas are characterized under the complex influences from the water absorption as well as the surface reflection and lateral waves. To validate the channel model, we compare the theoretical results with simulations derived by the COMSOL Multiphysics simulation tool. The developed channel model confirms the feasibility and lays the foundation of reliable MI underwater communications.