Robust and Accurate Wi-Fi Fingerprint Location Recognition Method Based on Deep Neural Network

• Main Authors: Yifan Wang, Jingxiang Gao, Zengke Li, Long Zhao
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Applied Sciences
• Subjects: indoor location recognition; received signal strength (<i>rss</i>); wi-fi fingerprint positioning; deep neural network (dnn); optimization methods; adaptive filter; hidden markov models (hmm)
• Online Access: https://www.mdpi.com/2076-3417/10/1/321

Currently, indoor locations based on the received signal strength (<i>RSS</i>) of Wi-Fi are attracting more and more attention thanks to the technology&#8217;s low cost, low power consumption and wide availability in mobile devices. However, the accuracy of Wi-Fi positioning is limited, due to the signal fluctuation and indoor multipath interference. In order to overcome this problem, this paper proposes a robust and accurate Wi-Fi fingerprint location recognition method based on a deep neural network (DNN). A stacked denoising auto-encoder (SDAE) is used to extract robust features from noisy <i>RSS</i> to construct a feature-weighted fingerprint database offline. We use the combination of the weights of posteriori probability and geometric relationship of fingerprint points to calculate the coordinates of unknown points online. In addition, we use constrained Kalman filtering and hidden Markov models (HMM) to smooth and optimize positioning results and overcome the influence of gross error on positioning results, combined with characteristics of user movement in buildings, both dynamic and static. The experiment shows that the DNN is feasible for position recognition, and the method proposed in this paper is more accurate and stable than the commonly used Wi-Fi positioning methods in different scenes.