Single-Anchor Indoor Localization Using Multi-Frequency RSSI Fingerprinting

Indoor localization based on wireless communication networks has attracted a lot of attention in research. It can deliver better accuracy than a traditional Global Navigation Satellite System (GNSS) and operate in environments where satellite signals can not be received. Although more accurate methods have been published, fingerprinting based on Received Signal Strength (RSS) remains interesting. Such a system can be deployed on top of most existing networks without imposing additional requirements or restrictions to the communication. However, existing solutions usually require a larger number of base stations with known locations (anchors) within a mobile node’s reception range. This is required to prevent ambiguous fingerprints and deliver accurate results. However, it also increases the network’s energy consumption and operating cost. In this paper, we present a new approach that uses multi-frequency fingerprints to eliminate this requirement and operates with only a single anchor node while achieving accuracy that is comparable to existing solutions. In order to efficiently collect RSSI fingerprints across multiple frequencies, we introduce a measurement methodology using Software Defined Radio (SDR).