CSI-MIMO: An efficient Wi-Fi fingerprinting using Channel State Information with MIMO

Robust Sub-Meter Level Indoor Localization With a Single WiFi Access Point—Regression Versus Classification

“…"HORUS", a typical fingerprint-based localization system, has been proposed in [8], which relies on the received signal strength indication (RSSI) to generate signal features. More accurate localization schemes have been proposed in [9]- [12], where the real time channel state information (CSI) are measured and processed instead to improve the localization accuracy. For example, SpotFi [9] and Chronos [10] extract the propagation parameters from CSIs, including angle of departure (AOD), angle of arrival (AOA), and time of flight (TOF) information, to compute the relative locations from the reference APs.…”

“…For example, SpotFi [9] and Chronos [10] extract the propagation parameters from CSIs, including angle of departure (AOD), angle of arrival (AOA), and time of flight (TOF) information, to compute the relative locations from the reference APs. Another common approach establishes a probabilistic model between the collected CSIs and the candidate locations through some classifiers such as deterministic k-nearest neighbor (KNN) clustering and probabilistic Bayes rule algorithms [11], [12]. The above fingerprintbased solutions are able to achieve sub-meter level accuracy if CSIs from multiple APs [9], multiple frequency bands [10] or multiple antennas [12] can be fused together.…”

“…Another common approach establishes a probabilistic model between the collected CSIs and the candidate locations through some classifiers such as deterministic k-nearest neighbor (KNN) clustering and probabilistic Bayes rule algorithms [11], [12]. The above fingerprintbased solutions are able to achieve sub-meter level accuracy if CSIs from multiple APs [9], multiple frequency bands [10] or multiple antennas [12] can be fused together. However, the corresponding computational overhead during the offline modeling and online feature extraction is usually significant as shown in [13].…”

Indoor detection of passive targets recast as an inverse scattering problem

“…The CSI is a fine-grained feature of the channel frequency response (CFR) providing both magnitude and phase information at multiple frequencies [11]. This indicator is highly sensitive to the environmental changes and its information content can be exploited to characterize the target signature on the electromagnetic field.…”

“…Recently, the channel state information (CSI) used by WLANs in the framework of orthogonal frequency division multiplexing (OFDM) has been exploited to enable location-based services. The CSI is a fine-grained feature of the channel frequency response (CFR) providing both magnitude and phase information at multiple frequencies [11]. This indicator is highly sensitive to the environmental changes and its information content can be exploited to characterize the target signature on the electromagnetic field.…”