Low-Power LoRa Signal-Based Outdoor Positioning Using Fingerprint Algorithm

Wongeun Choi,Yeonuk Jung,Yoon-Seop Chang,Junkeun Song

doi:10.3390/ijgi7110440

Abstract

Positioning is an essential element in most Internet of Things (IoT) applications. Global Positioning System (GPS) chips have high cost and power consumption, making it unsuitable for long-range (LoRa) and low-power IoT devices. Alternatively, low-power wide-area (LPWA) signals can be used for simultaneous positioning and communication. We summarize previous studies related to LoRa signal-based positioning systems, including those addressing proximity, a path loss model, time difference of arrival (TDoA), and fingerprint positioning methods. We propose a LoRa signal-based positioning method that uses a fingerprint algorithm instead of a received signal strength indicator (RSSI) proximity or TDoA method. The main objective of this study was to evaluate the accuracy and usability of the fingerprint algorithm for large areas in the real world. We estimated the locations using probabilistic means based on three different algorithms that use interpolated fingerprint RSSI maps. The average accuracy of the three proposed algorithms in our experiments was 28.8 m. Our method also reduced the battery consumption significantly compared with that of existing GPS-based positioning methods.

Highlights

In recent years, the number of Internet of Things (IoT) devices has increased exponentially with the decreasing costs of hardware and communication technologies [1]
We propose a LoRa-signal-based positioning method that uses a fingerprint algorithm instead of the received signal strength indicator (RSSI) proximity or time difference of arrival (TDoA) methods
We have proposed a LoRa signal-based positioning method that uses a fingerprint algorithm instead of the RSSI proximity or TDoA method

Summary

Introduction

The number of Internet of Things (IoT) devices has increased exponentially with the decreasing costs of hardware and communication technologies [1]. Medium- and long-range IoT devices use both cellular- and noncellular-based communication technologies. Low-power wide-area (LPWA) communication, a noncellular-based communication technology, allows long-range communication among IoT devices with low power consumption and cost. LPWA communication is highly suitable for long-range wireless IoT devices despite its low bandwidth constraint. Geo-Inf. 2018, 7, 440 ISPRS Int. J. The LoRaWAN RSSI proximity method determines whether a LoRa gateway is located nearby by examining whether a signal can be received from it. We propose a LoRa-signal-based positioning method that uses a fingerprint algorithm instead of the RSSI proximity or TDoA methods.

Related Work

RSSI Proximity and Path-Loss-Model-Based Positioning

Proposed Fingerprint Algorithm

Experimental Results

Conclusions