Reliable Through-Metal Wireless Communication Using Magnetic Induction

Abstract

Wireless sensors or robots in metal-constrained environments leverage through-metal wireless communications to send data and receive instructions. It is well-known that wireless radio frequency (RF) signals cannot penetrate through metal efficiently, which prevents us from applying existing wireless solutions. Moreover, most applications, e.g., metal inspection robots in an oil pipeline, require noncontact wireless communications, where the ultrasonic signals do not work. To this end, we propose to use magnetic induction communication to provide a reliable and flexible solution for wireless sensor and robotic networks in metal-constrained environments. We consider the transceivers are located on two different sides of a metal wall. Then, we develop an analytical model to obtain the optimal configurations of the magnetic coil and the carrier frequency to maximize the communication channel capacity. The received power and wireless channel bandwidth are studied. The results show that the optimal carrier frequency is around 1 kHz. In addition, we study the negative effects caused by coil misalignment and interference, which are circumvented by leveraging a coil array with optimal receiving strategy. The results are evaluated using numerical simulation and verified by finite element method-based simulation.