Low-complexity offline and online strategies for Wi-Fi fingerprinting indoor positioning systems

Indoor localization of wireless mobile devices, also referred to as indoor positioning, is nowadays an intensively investigated research topic, toward the extension of outdoor location-based services to indoor environments. Among the available communication technologies and infrastructures, Wi-Fi appears as an excellent localization support, since it is largely widespread in indoor environments, implying low implementation time and costs; in turn, fingerprinting is one of the most investigated techniques for the implementation of Wi-Fi indoor positioning systems (IPSs). This chapter analyzes and discusses the trade-off between accuracy and complexity, within offline and online phases of Wi-Fi fingerprinting IPSs. The main goal is to identify and derive low-complexity strategies, leading to a simple system implementation, while preserving the achievable positioning accuracy.