To improve the accuracy and stability of the indoor localization system, this paper proposes a fingerprinting positioning technique based on Wi-Fi channel state information (CSI). The CSI characterizes fine-grained channel information through subcarriers, which can better eliminate interferences such as multipath effect. Based on the CSI, an efficient and accurate construction scheme for fingerprints database is achieved with the matrix completion theory, and a stable and real-time fingerprint matching method is implemented with the Bayesian rule. The field evaluation results in two scenarios show that the proposal achieves the desired goals in terms of both fingerprints database construction accuracy and localization performance.
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