Dual-domain signal error compensation algorithm for indoor positioning based on channel sounding
Jiachao Xu, Ningning Qin, Yan WangPurpose
This study aims to address the problem that Bluetooth Channel Sounding phase observations are prone to distortion in complex indoor multipath environments; this paper proposes a dual-domain signal error compensation method for robust indoor ranging and positioning.
Design/methodology/approach
The proposed method integrates frequency-domain phase purification and time-domain first-arrival path extraction. Linear phase bias is first calibrated from repeated observations and nonlinear residual phase errors are modeled to restore purified channel phase vectors. A Dynamic Delay Search Engine (DDSE) is then constructed to constrain Orthogonal Matching Pursuit (OMP) in the delay domain, thereby suppressing coherent multipath pseudopeaks and improving first-arrival path extraction. Multi-base-station ranging results are finally fused through nonlinear least-squares positioning.
Findings
Experimental results in a typical indoor scenario show that the proposed method achieves a ranging root mean square error (RMSE) of 0.38 m and a positioning RMSE of 0.60 m. The method outperforms phase-based ranging, inverse fast Fourier transform, MUSIC and iterative Bayesian baselines, demonstrating improved robustness against multipath interference and phase distortion.
Originality/value
This study develops a frequency-time dual-domain compensation framework for Bluetooth CS-based indoor positioning. By combining hierarchical frequency-domain phase compensation with DDSE-constrained sparse delay reconstruction, it provides a practical approach for sub-meter indoor localization under non-line-of-sight multipath conditions.