Ranging Measurement Estimation Based on 5G Downlink PRS

The Global Navigation Satellite Systems (GNSS) achieve high-accuracy positioning in open outdoor areas. However, their positioning performance remains constrained in complex environments such as urban canyons and tunnels. 5G provides possibilities for high-accuracy positioning due to its abundant spectrum resources and diverse positioning signals. For distance-based 5G positioning methods, high-accuracy ranging is a prerequisite for achieving precise positioning. However, current 5G positioning methods typically rely on basic synchronization signals, such as Primary Synchronization Signal (PSS), which provide limited delay resolution and lack experimental validation. To address these limitations, this paper proposes a ranging measurement estimation method based on the 5G Downlink Positioning Reference Signal (DL-PRS). By exploiting the high delay-resolution properties of PRS, the proposed method enables accurate estimation of both Time of Arrival (TOA) and Round-Trip Time (RTT). An experimental platform based on Software Defined Radio (SDR) is developed to implement and evaluate the ranging method. The results show that the proposed method achieves meter-level ranging accuracy in the open indoor scenario, which provides support for high-accuracy 5G PRS positioning.