3D Coverage Measurement and Modeling of Specular Multipaths for Indoor Localization

Resolvable specular multipath components (SMCs) are helpful for single-anchor robust indoor positioning as they can be used to infer reliable information about the geometric structure among the anchor, mobile user, and reflective surface (which is usually assumed to be stationary). The number and power of resolvable SMCs has a direct impact on the performance of various single-anchor indoor positioning algorithms. Given a fixed anchor and a reflective surface with limited area, the associated single-bounce SMC is only observable in a particular 3-dimensional (3D) space. Such a 3D space is called the "coverage" of SMC. This paper makes an initial effort to measure and model the SMC coverage in the 3GHz to 6GHz band. A vector network analyzer is used for channel measurements in anechoic chamber and indoor office environments. The measured results are compared against an ideal ray tracing model. Special attentions are paid to capture real-world SMC variations caused by the size and roughness of the reflective surfaces. For positioning purpose, a geometric-awared semi-deterministic SMC coverage model is suggested based on our findings.