PILA: Sub-Meter Localization Using CSI from Commodity Wi-Fi Devices.

Zengshan Tian,Yue Jin,Zipeng Wu,Ze Li,Mu Zhou

doi:10.3390/s16101664

Zengshan Tian, Yue Jin + Show 3 more

Open Access

https://doi.org/10.3390/s16101664

Copy DOI

Abstract

The aim of this paper is to present a new indoor localization approach by employing the Angle-of-arrival (AOA) and Received Signal Strength (RSS) measurements in Wi-Fi network. To achieve this goal, we first collect the Channel State Information (CSI) by using the commodity Wi-Fi devices with our designed three antennas to estimate the AOA of Wi-Fi signal. Second, we propose a direct path identification algorithm to obtain the direct signal path for the sake of reducing the interference of multipath effect on the AOA estimation. Third, we construct a new objective function to solve the localization problem by integrating the AOA and RSS information. Although the localization problem is non-convex, we use the Second-order Cone Programming (SOCP) relaxation approach to transform it into a convex problem. Finally, the effectiveness of our approach is verified based on the prototype implementation by using the commodity Wi-Fi devices. The experimental results show that our approach can achieve the median error 0.7 m in the actual indoor environment.

Highlights

With the increase of the demand for the ubiquitous Location-based Services (LBSs), localization and navigation applications become more important in daily life
People prefer to use the Global Navigation Satellite System (GNSS) to achieve the LBSs, whereas the signal from the satellites cannot be received in indoor environment, which results in the failure of the GNSS
Considering the fact that the error of the Channel State Information (CSI) results in the additional noise in the Time of Arrival (TOA) estimation, we propose to use the phase sanitization algorithm to remove the interference of this error before estimating the AOA and Different from the existing indoor localization systems which integrate multiple types of measurements [9,10], we propose a new linear Least Square (LS)-based object function for the localization

Summary

Introduction

With the increase of the demand for the ubiquitous Location-based Services (LBSs), localization and navigation applications become more important in daily life. People prefer to use the Global Navigation Satellite System (GNSS) to achieve the LBSs, whereas the signal from the satellites cannot be received in indoor environment, which results in the failure of the GNSS. Up to now, existing Wi-Fi localization systems are mainly based on the Angle-of-arrival (AOA) or Received Signal Strength (RSS) measurement. The accuracy of the AOA measurement-based localization systems is around 0.4 m [1,2]. They measure the AOA of the signal from at least two Access Points (APs), and use the triangulation algorithm to locate the target

Objectives

Methods

Findings

Conclusion