Indoor Localization with Irregular Antenna Deployment

Abstract

This paper presents an accurate indoor localization system with irregular deployment of antennas. It can be feasibly deployed on commodity Wi-Fi infrastructures, without any hardware or firmware modifications. Aided by elaborate phase processing and an enhanced angle of arrival (AoA) estimation algorithm, our proposed system could provide higher localization accuracy under the coverage of two line-of-sight (LOS) access points (APs) compared to the state-of-the-art localization systems, where at least three APs are utilized to achieve the same accuracy. To be specific, a pertinent phase compensation and sanitization algorithm is designed to eliminate the additional factors that will distort the genuine channel state information (CSI). On this basis, we make the antennas irregularly deployed at each AP such that the linear array symmetry is removed and more AoAs can be obtained. In particular, with two APs equipped with 3 antennas irregularly deployed, up to 4 AoAs could be obtained (more than 2 AoAs with linear array), which provides the ability to localize a target in a 3-D space. Our experiments in a multipath rich indoor environment show that our system achieves a higher localization accuracy than the state-of-the-art localization systems, namely, a median error accuracy of 1.2 m in 2-D localization and 1.45 m in 3-D localization with two APs.