MonoStream: A Minimal-Hardware High Accuracy Device-free WLAN Localization System

TL;DR

MonoStream is a novel device-free WLAN localization system that uses a single stream and Channel State Information to achieve high accuracy and low latency, suitable for real-time tracking in small environments.

Contribution

MonoStream introduces a single-stream DF localization approach leveraging CSI and MIMO data, with a novel feature set and modeling as an object recognition problem.

Findings

Achieves 0.95m localization accuracy

At least 26% improvement over state-of-the-art

Per-location update time less than 23ms

Abstract

Device-free (DF) localization is an emerging technology that allows the detection and tracking of entities that do not carry any devices nor participate actively in the localization process. Typically, DF systems require a large number of transmitters and receivers to achieve acceptable accuracy, which is not available in many scenarios such as homes and small businesses. In this paper, we introduce MonoStream as an accurate single-stream DF localization system that leverages the rich Channel State Information (CSI) as well as MIMO information from the physical layer to provide accurate DF localization with only one stream. To boost its accuracy and attain low computational requirements, MonoStream models the DF localization problem as an object recognition problem and uses a novel set of CSI-context features and techniques with proven accuracy and efficiency. Experimental evaluation in two typical testbeds, with a side-by-side comparison with the state-of-the-art, shows that MonoStream can achieve an accuracy of 0.95m with at least 26% enhancement in median distance error using a single stream only. This enhancement in accuracy comes with an efficient execution of less than 23ms per location update on a typical laptop. This highlights the potential of MonoStream usage for real-time DF tracking applications.