A New Method of High-Precision Positioning for an Indoor Pseudolite without Using the Known Point Initialization

Area of Science:

• GNSS (Global Navigation Satellite System) and indoor positioning technologies.
• Signal processing and estimation algorithms for high-precision localization.

Background:

• Traditional indoor pseudolite positioning relies on Known Point Initialization (KPI) and the LAMBDA method for ambiguity resolution.
• Pseudorange errors from multipath, noise, and clock issues necessitate robust positioning techniques.
• Existing methods can be computationally intensive or require specific initialization procedures.

Purpose of the Study:

• To develop a novel, high-precision indoor pseudolite positioning method that eliminates the need for KPI.
• To achieve rapid and accurate initial coordinate estimation for effective ambiguity resolution.
• To enhance the efficiency and accuracy of indoor localization systems.

Main Methods:

• Utilizing the static differential pseudolite system (DPL) for initial low-accuracy coordinate acquisition.
• Employing the ambiguity function method (AFM) to refine coordinates and meet LAMBDA's accuracy requirements.
• Integrating AFM results as initial values for the LAMBDA method to fix carrier phase ambiguities.

Main Results:

• The DPL method achieved decimeter-level accuracy for initial coordinates.
• The AFM, with optimized search parameters, provided centimeter-level precision and high efficiency.
• The combined method successfully fixed double-difference carrier phase ambiguities.
• Experimental results demonstrated centimeter-level accuracy for dynamic tests and millimeter-level for static tests.

Conclusions:

• The proposed KPI-free method effectively enables high-precision indoor pseudolite positioning.
• The integration of DPL and AFM offers a robust solution for rapid and accurate initial positioning.
• This approach significantly improves ambiguity resolution and overall positioning performance in challenging indoor environments.