Low-Complexity RSS-based Underwater Localization with Unknown Transmit Power
Yingquan Li, Jiajie Xu, Bodhibrata Mukhopadhyay, Mohamed-Slim Alouini
TL;DR
The paper tackles RSS-based underwater localization when the target’s transmit power is unknown. It introduces GUTP, a weighted RSS approach that uses a generalized trust region subproblem (GTRS) solved via a simple bisection to jointly estimate position and transmit power. The authors derive CRLBs for both known and unknown Pt and show through extensive simulations that GUTP achieves higher localization accuracy and significantly lower computational complexity than SDP-based benchmarks. The method demonstrates robustness to noise characteristics and model biases, highlighting its practical potential for low-cost UWSN deployments. Overall, GUTP offers a scalable, theoretically sound, and efficient solution for underwater target localization with uncertain transmission power.
Abstract
Underwater wireless sensor networks (UWSNs) have received significant attention due to their various applications, with underwater target localization playing a vital role in enhancing network performance. Given the challenges and high costs associated with UWSN deployments, Received Signal Strength (RSS)-based localization offers a viable solution due to its minimal hardware requirements and cost-effectiveness. In this paper, we assign distance-based weights to RSS measurements, providing higher reliability to closer anchor nodes. Using the weighted RSS measurements and generalized trust region subproblem (GTRS), we propose the GTRS-based localization technique with Unknown Transmit Power (GUTP), which can be solved by a simple bisection method. Unlike conventional localization methods that require prior knowledge of the target node's transmit power, GUTP jointly estimates both the location and transmit power of the target node, broadening its practical use. Additionally, we derive the Cramer-Rao lower bounds (CRLBs) for RSS-based underwater localization with known and unknown transmit power, respectively. Extensive simulations demonstrate that GUTP achieves enhanced accuracy and significantly lower computational complexity in estimating the target node's location and transmit power compared to existing semidefinite programming (SDP)-based techniques.
