Environment-Independent SNR Measurement Method for Underwater Acoustic Communication Systems

Underwater acoustic communication (UAC) is used as a means of long-range communication for autonomous underwater vehicles (AUVs) and underwater wireless sensor networks (UWSNs). The signal-to-noise ratio (SNR) is an important metric for predicting the communication range and transmission rate in UAC systems. The SNR measurements of input SNR (ISNR) and output SNR (OSNR) are widely used in acoustic modems. However, they are sensitive to acoustic reflections, and their measured values depend on the communication environment. This paper presents a pure carrier-to-noise ratio (PCNR) method that extracts only signal power derived from sound propagation loss. This method enables environment-independent SNR measurements. The effectiveness of the proposed method is verified through simulations and experiments conducted in a water tank.