Optimizing LoRa for Underwater Acoustic Links: Carrier Frequency and Spreading Factor Trade-Offs

Abstract

Underwater Acoustic Communication (UWAC) is critical in environments where RF/Optical signals attenuate rapidly. This paper validates Long Range (LoRa) as a robust UWAC solution, leveraging its resilience to multipath fading and Doppler shifts. Comprehensive simulations analyzed low (10 kHz), medium (30 kHz), and high (50 kHz) frequencies with spreading factors (SF) (7-12). Higher SFs have been validated to reduce required SNR by 18 dB, while carrier frequencies govern range-data rate tradeoffs. We provide practical guidelines: low frequencies with high SFs for sensor networks, medium frequencies with mid-range SFs for underwater vehicles, and higher frequencies with lower SFs for short-range applications. This work presents a novel adaptive optimization framework for LoRa-based UWAC systems, enabling robust long-range networks for various underwater applications.