Indoor Positioning Using Acoustic Pseudo-Noise Based Time Difference of Arrival

• Main Author: Luong, Nicholas J
• Format: Others
• Published: DigitalCommons@CalPoly 2020
• Subjects: Indoor Positioning; Sensor Network; TDoA; Pseudo-noise; Acoustic; Time Reversal; Signal Processing; Systems and Communications
• Online Access: https://digitalcommons.calpoly.edu/theses/2137; https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=3652&context=theses

The Global Positioning System (GPS) provides good precision on a global scale, but is not suitable for indoor applications. Indoor positioning systems (IPS) aim to provide high precision position information in an indoor environment. IPS has huge market opportunity with a growing number of commercial and consumer applications especially as Internet of Things (IoT) develops. This paper studies an IPS approach using audible sound and pseudo-noise (PN) based time difference of arrival (TDoA). The system’s infrastructure consists of synchronized speakers. The object to be located, or receiver, extracts TDoA information and uses multilateration to calculate its position. The proposed IPS utilizes sound waves since they travel much slower compared to electromagnetic waves, allowing for easier measurements. Additionally, the audible spectrum has a large availability of low directivity speakers and microphones allowing for a large coverage area compared to highly directive ultrasonic transceivers. This paper experimentally evaluates the feasibility of the proposed IPS.