FIFS: Fine-Grained Indoor Fingerprinting System

• DOI: 10.1109/icccn.2012.6289200
• Publication Date: 2012-09-07T19:57:53Z
• Authors: Jiang Xiao; Kaishun Wu; Youwen Yi; Lionel M. Ni
• Keywords: RSS; Indoor positioning system; Diversity scheme; Antenna diversity; Channel state information; Signal strength

WLAN-based indoor location fingerprinting has been attractive owing to the advantages of open access and high accuracy. Most fingerprinting-based systems so far rely on received signal strength (RSS), which can be easily measured at receiver with commercial WLAN equipment. However, RSS is a coarse value simply measures power for whole channel. Thus, it fluctuates over time in typical environments rich multipath effects not unique specific location. In this paper, we present design, implementation, evaluation Fine-grained Indoor Fingerprinting System (FIFS). FIFS explores PHYlayer Channel State Information (CSI) that specifies channel status all subcarriers WLAN. The system leverages CSI values including different amplitudes phases multiple propagation paths, known as frequency diversity, uniquely manifest Moreover, antennas provides spatial diversity further augmented fingerprinting. We also coherence bandwidth-enhanced probability algorithm correlation filter map object fingerprints. conducted experiments two scenarios IEEE 802.11 NICs. experimental results demonstrate overall positioning accuracy improved compared RSS-based Horus system.