A Ray-Tracing Based Fingerprinting for Indoor Positioning

Indoor wireless positioning technique has huge market value and is one of the most active research topics in recent years. Received signal strength (RSS) measurement is the main category in wireless positioning technique since the information of RSS can be collected easily. With the rapidly development of OFDM-based wireless broadband system, channel impulse response (CIR) measurement and more accurate RSS measurement can be obtained. In the paper, we develop a OFDM-based channel sounding system to perform a series of channel measurement experiments to collect offline and online measurements. Moreover, the ray-tracing (RT) technique is utilized to simulate CIR measurement. We propose a ray-tracing based fingerprinting (RBFP) positioning technique, which evaluates the similarity between the online measurement and the simulated CIR database using RT. The error of the proposed RBFP is validated in the experiment that has performance comparable with the traditional fingerprinting (FP).