Time delay characteristics analysis of UWB diffraction propagation in indoor NLOS environment

Indoors, the ultrawideband (UWB) signal line-of-sight (LOS) propagation is affected by the complexity of space structure, and the UWB time-of-flight (TOF) based ranging information in the non-line-of-sight (NLOS) environment will show evident positive errors. Therefore, the complexity of indoor spatial structure has been the main reason limiting the improvement of UWB positioning accuracy, yet the error characteristics caused by NLOS diffraction propagation have not been extensively studied. In this letter, firstly, the diffraction propagation characteristics of UWB in NLOS environment and its influencing factors are analyzed experimentally, based on which the diffraction propagation characteristics are studied and the relationship between diffraction delay and diffraction angle is explored. Finally, the time-delay model of UWB diffraction propagation is designed and the validity of the model is verified, and the range accuracy is improved by 82.61% after compensation.