Indoor Carrier Phase Positioning Technology Based on OFDM System.

Area of Science:

• Wireless communication
• Signal processing
• Navigation systems

Background:

• Carrier phase measurement is a high-resolution ranging technique crucial for high-precision positioning.
• While widely used in GNSS, its application in wireless OFDM systems for positioning is limited.
• OFDM carrier phase positioning faces challenges from multipath, non-line-of-sight (NLOS) propagation, and integer ambiguity resolution.

Purpose of the Study:

• To develop a carrier phase ranging scheme for OFDM systems in multipath environments.
• To address the challenges of integer ambiguity resolution and NLOS error mitigation in OFDM positioning.
• To enhance positioning accuracy in wireless systems using carrier phase measurements.

Main Methods:

• A novel ranging scheme based on carrier phase measurement in multipath conditions.
• Development of an extended Kalman filter (EKF) algorithm for real-time processing.
• Simulation-based evaluation of the proposed EKF algorithm for ambiguity resolution and error mitigation.

Main Results:

• The EKF algorithm successfully achieves fast integer ambiguity resolution.
• The proposed method mitigates the impact of NLOS errors on positioning accuracy.
• Simulations demonstrate positioning errors of less than 30 centimeters for 90% of terminals.

Conclusions:

• The presented carrier phase ranging scheme and EKF algorithm offer excellent performance for high-precision positioning in OFDM systems.
• The method is robust even in the presence of NLOS errors.
• This approach significantly improves positioning accuracy in wireless environments.