Comparison of Phase-Based 3D Near-Field Source Localization Techniques for UHF RFID

Area of Science:

• Electrical Engineering
• Robotics
• Signal Processing

Background:

• Accurate localization of backscatter devices is crucial for various applications, including robotics and the Internet of Things.
• Existing localization methods often face challenges in 3D environments and with limited antenna configurations.

Purpose of the Study:

• To evaluate and enhance phase-based localization techniques for narrowband backscatter tags in 3D space.
• To investigate the impact of different transceiver modes and antenna array configurations on localization accuracy.
• To propose a novel Singledimensional-MIMO (S-MIMO) transceiver mode for mobile robot systems.

Main Methods:

• Application of Beamformer and MUSIC algorithms for 3D backscatter localization.
• Evaluation of various transceiver modes, including MIMO and the proposed S-MIMO.
• Monte-Carlo simulations with a realistic multipath error model for accuracy assessment.
• Experimental validation using a synthetic uniform rectangular array and an Ultra High Frequency (UHF) RFID setup.

Main Results:

• Achieved mean localization accuracy of less than 30 cm in an indoor environment.
• Demonstrated that transceiver modes significantly impact localization performance.
• Showcased the influence of aperture-tag distance and array parameters (size, grid spacing) on accuracy.
• Validated simulation results with experimental UHF RFID measurements.

Conclusions:

• Phase-based localization techniques, combined with optimized antenna arrays and transceiver modes, enable accurate 3D positioning of backscatter tags.
• The proposed S-MIMO mode offers suitability for mobile robotic applications.
• Further optimization of array design can lead to centimeter-level localization accuracy and improved array efficiency.