An Absorption Mitigation Technique for Received Signal Strength-Based Target Localization in Underwater Wireless...

Area of Science:

• Engineering
• Computer Science
• Marine Technology

Background:

• Accurate localization is crucial for underwater wireless sensor networks (UWSNs) supporting marine applications, routing, and topology control.
• Received Signal Strength (RSS)-based localization is cost-effective and synchronization-free but degraded by underwater acoustic signal absorption loss.
• Existing RSS-based methods struggle with accuracy in UWSNs due to environmental signal attenuation.

Purpose of the Study:

• To develop a robust localization method for UWSNs that overcomes the limitations of RSS-based schemes.
• To introduce an absorption mitigation technique (AMT) to enhance localization accuracy in underwater environments.
• To provide a computationally tractable solution for non-convex optimization problems in UWSN localization.

Main Methods:

• An analytically tractable RSS-based measurement model with Maximum Likelihood Estimator (MLE) was formulated.
• A min-max strategy was employed to address the non-convex optimization problem involving absorption loss.
• The problem was framed as a generalized trust region sub-problem (GTRS) solved via an iterative method.
• The Cramer-Rao Lower Bound (CRLB) for the measurement model was derived.

Main Results:

• The proposed absorption mitigation technique (AMT) effectively addresses signal absorption loss in UWSNs.
• The developed iterative method provides a solution for the non-convex GTRS localization problem.
• Numerical simulations validated the method's effectiveness compared to state-of-the-art approaches.
• The derived CRLB offers a benchmark for localization accuracy.

Conclusions:

• The novel robust localization method significantly improves accuracy in UWSNs by mitigating absorption loss.
• The absorption mitigation technique (AMT) enhances the viability of RSS-based localization in challenging underwater conditions.
• This research offers a practical and effective solution for UWSN localization, advancing marine technology applications.