Abstract
With the increasing popularity of location-based services, channel state information (CSI) has received widespread attention in positioning due to the fine-grained information it provides. However, the raw amplitudes of CSI are especially sensitive to noise and easily effected by the frequency-selective fading. As the expanding of test area, positioning is disturbed by random noise and insufficient resolution of features severely. In this paper, we propose Cluster-Mapping (C-Map), an adaptive pre-processing system for CSI amplitude-based fingerprint localization. This system models positioning as a classification problem, an adaptive processing mechanism is constructed according to the characteristics of CSI amplitude. C-Map mainly contains two parts: dynamic denoising and feature enhancement. In the dynamic denoising, effective features are screened out by clustering iteratively, without specifying parameters according to the experimental environment. In the feature enhancement, polynomial fitting with regularization is used to reduce jagged fluctuations, then the trend of variation over 30 sub-carriers are described by combining derivation with nonlinear kernel function. Extensive experiments are conducted in typical environments to verify the superior performance of C-Map for the preprocessing of CSI amplitude. Compared with the combination of mean and multidimensional scaling (MDS), the average positioning error of C-Map is reduced 28.1% in comprehensive indoor environment, and 19% in garage. Furthermore, compared with the combination of DBSCAN and principal component analysis (PCA), the average positioning error of C-Map is reduced 33.1% in comprehensive indoor environment, and 28% in garage.
Highlights
With the gradual popularization of mobile devices, locationbased services (LBS) have received significant attention for smart cities, industrial production and people’s daily lives
We propose an adaptive pre-processing system based on channel state information (CSI) amplitude, named Cluster-Mapping (C-Map)
Both the transmitter and the receiver are mobile terminals equipped with Intel 5300 NIC, in which one antenna is installed at the transmitter and three antennas are installed at the receiver
Summary
With the gradual popularization of mobile devices, locationbased services (LBS) have received significant attention for smart cities, industrial production and people’s daily lives. CSI provides ample features including phases and amplitudes of multiple sub-carriers, and presents fine-grained information of signal propagation. As can be seen from the above, existing pre-processing methods for CSI amplitude mainly focus on two aspects: 1) improving the discrimination of features, 2) reducing the impact of noise. The former is mainly realized by expanding space and increasing bandwidth. This paper makes notable contributions summarized as follows: 1) An adaptive pre-processing system for CSI amplitude is proposed, which alleviates the interference of noise and improves the resolution of features adaptively. The adaptive pre-processing system C-Map is mainly designed for amplitude of CSI
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
