Experimental Validation of 5G Positioning With Inter-Cell Clock Bias Correction

The advancement of fifth generation (5G) cellular networks offers significant opportunities for positioning services, yet the performance of these systems is currently hindered by the clock offset among 5G base stations in commercial networks, here referred to as inter-cell clock bias (ICCB). These biases introduce systematic errors in time of arrival (TOA) measurements, degrading localization accuracy. This paper addresses this challenge by utilizing a stationary reference receiver to estimate and correct the ICCBs. By aligning the timing references of multiple base stations, our single-difference correction method enables accurate standalone positioning using opportunistically received synchronization signal block (SSB) data. The proposed method was validated with three independent measurement campaigns at the same rural location on broadcast signals from a commercial 5G network. The results demonstrate the effectiveness of the ICCB correction, showing a 73%-84% reduction in positioning error compared to uncompensated methods. Applying a smoothing filter to the ICCB corrections further improves the mean accuracy by about 18%-19%, achieving a mean error between 12.7m and 20.6m across the three tests. While this performance is constrained by the limited bandwidth of the current commercial 5G deployment at 3.68 GHz, our findings confirm the feasibility of leveraging public 5G signals for location-based services.