Disaster Detection in Magnetic Induction based Wireless Sensor Networks with Limited Feedback

The use of magnetic induction (MI) based transmissions in challenging environments has been investigated in various works. Recently, a system model has been proposed, which explains how the MI based transmission channel depends on the chosen system parameters. In order to make the system robust against environmental changes, the system parameters like resonance frequency and modulation scheme need to be properly adapted to the current channel state. It is frequently assumed, that perfect channel state information (CSI) is available at the transmitter and at the receiver. However, in practical systems this knowledge may not always be easily acquired. In addition, a permanent feedback signaling is needed in order to update the CSI at the transmitter, which usually causes interference to the surrounding devices and reduces the energy efficiency. In this paper, we investigate the potential of a recently proposed approach for channel estimation within the MI transmitter circuit without explicit feedback signaling of CSI. This technique seems promising especially for disaster detection in wireless underground sensor networks, which is the main focus of this work.