AOA-Based Three-Dimensional Multi-Target Localization in Industrial WSNs for LOS Conditions

Area of Science:

• Wireless Sensor Networks
• Localization Algorithms
• Signal Processing

Background:

• High-precision relative positioning of numerous mobile sensor nodes (MSNs) is vital for smart industrial wireless sensor networks (SIWSNs).
• Simultaneous three-dimensional (3D) positioning of multiple targets remains an underexplored area.
• Existing methods often require complex hardware or synchronization, limiting their industrial applicability.

Purpose of the Study:

• To develop a novel approach for high-precision, simultaneous 3D localization of multiple MSNs in SIWSNs.
• To address the limitations of existing multi-target localization techniques in industrial environments.
• To enhance the efficiency and accuracy of wireless sensor network positioning.

Main Methods:

• Proposed Angle-of-Arrival (AOA) based Three-dimensional Multi-target Localization (ATML) utilizing two anchor nodes with antenna arrays.
• Designed a multi-target single-input-multiple-output (MT-SIMO) signal transmission scheme.
• Employed an iterative maximum likelihood estimator (MLE) for 2D AOA estimation and the skew line theorem for 3D location refinement.

Main Results:

• ATML successfully achieved simultaneous high-precision localization of multiple MSNs in both simulations and a physical testbed.
• The approach effectively leveraged spread spectrum and antenna array gains for improved accuracy and efficiency.
• Validated the system's robustness against interference and multipath effects common in industrial settings.

Conclusions:

• The proposed ATML method offers a highly accurate and efficient solution for multi-target 3D localization in SIWSNs.
• ATML demonstrates practical viability due to its independence from extra hardware and node synchronization.
• The technique shows significant potential for enhancing industrial wireless sensor network performance and reliability.