Underground Wireless Communication Using Toroidal Antennas and Steel Casing in Downhole Environments

Underground wireless communication presents significant challenges due to high attenuation and signal distortion in conductive subsurface environments. This paper investigates the feasibility of toroidal antenna-based communication using steel casing to enhance communication for downhole applications. A comprehensive simulation framework integrating COMSOL Multiphysics for electromagnetic modeling and Simulink for communication system analysis is developed to evaluate system performance. The study examines the impact of mutual inductance between transmitter and receiver, frequency, and transmission distance on received signal strength and reliability. Two modulation schemes, amplitude-shift keying (ASK) and frequency-shift keying (FSK), are analyzed to compare their bit error rate (BER) performance under varying noise levels and channel conditions. The results demonstrate that FSK provides superior noise resilience and long-range reliability, while ASK is more power-efficient for short-range communication. The Simulink-measured BER closely aligns with theoretical predictions, validating the simulation model.