Survey of CSI fingerprinting-based indoor positioning and mobility tracking systems

• Published in: IET signal processing Vol. 14; no. 7; pp. 407 - 419
• Main Authors: Rocamora, Josyl Mariela, Wang-Hei Ho, Ivan, Mak, Wan-Mai, Lau, Alan Pak-Tao
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.09.2020
• Subjects: acquired fingerprint data; calculated distances; channel state information; cm‐level positioning accuracy; CSI; fingerprint identification; high positioning resolution; indoor communication; indoor positioning systems; indoor radio; MIMO communication; mobility tracking systems; multiple reference points; multiple‐input multiple‐output antennas; nonline‐of‐sight channels; position estimate; range‐based methods; range‐free strategies; received signal strength indicator; Review Article; signal preprocessing; single reference point; site surveying; tracking; wireless sensor networks; fingerprint identification; calculated distances; wireless sensor networks; nonline-of-sight channels; multiple-input multiple-output antennas; received signal strength indicator; channel state information; cm-level positioning accuracy; single reference point; tracking; mobility tracking systems; range-based methods; high positioning resolution; multiple reference points; position estimate; range-free strategies; site surveying; indoor positioning systems; acquired fingerprint data; CSI; signal preprocessing; indoor communication; indoor radio; MIMO communication
• ISSN: 1751-9675; 1751-9683; 1751-9683
• DOI: 10.1049/iet-spr.2020.0028

Techniques for indoor positioning systems (IPSs) can be categorised as range-based or range-free. Range-based methods rely on geometric mappings to approximate a location given the calculated distances or angles from multiple reference points. In contrast, range-free strategies utilise fingerprinting, wherein an acquired fingerprint data is compared to a pre-collected dataset to identify the best position estimate. Among these, fingerprinting of channel state information (CSI) is preferred over other information such as received signal strength indicator as the former can exploit the effect of multipath propagation and is robust against non-line-of-sight channels. CSI has the potential to achieve cm-level positioning accuracy with a single reference point only. In this study, the authors survey CSI fingerprinting-based indoor positioning and mobility tracking systems. The process of fingerprinting that includes site surveying and signal preprocessing is discussed in detail. They determine the potential challenges of such systems and propose remedies to improve positioning accuracy. In general, spatial diversity, such as multiple-input multiple-output antennas and wireless sensor networks, or frequency diversity (e.g. high subcarrier count, frequency hopping mechanism) are exploited to achieve high positioning resolution. Such IPS can also be enhanced via additional sensors or spatial graphs for motion detection and tracking.