Publications by Joachim Tobias Tapparel

LoRa Fine Synchronization with Two-Pass Time and Frequency Offset Estimation

Andreas Peter Burg, Joachim Tobias Tapparel

LoRa is currently one of the most widely used low-power wide-area network (LPWAN) technologies. The physical layer leverages a chirp spread spectrum modulation to achieve long-range communication with low power consumption. Synchronization at long distance ...

IEEE2024

Centralized RAN for LPWAN: Architecture and Proof-of-Concept Prototype Implementation

Andreas Peter Burg, Joachim Tobias Tapparel

Centralized radio access networks (C-RAN) are widely recognized as an enabling technology for the evolution of cellular systems, including 5G and beyond. However, the concept is not limited to 3GPP cellular systems and licensed frequency bands. In recent y ...

Institute of Electrical and Electronics Engineers Inc.2024

Increasing LoRa Sensitivity and Reliability with an IoT Cloud RAN

Andreas Peter Burg, Joachim Tobias Tapparel

LoRaWAN is one of the most popular low-power wide-area network (LPWAN) technologies. Its network architecture is based on a star-of-stars topology, in which LoRa nodes communicate with gateways that forward payloads to a central server when a packet detect ...

IEEE Computer Society2023

A Maximum-Likelihood-Based Two-User Receiver for LoRa Chirp Spread-Spectrum Modulation

Andreas Peter Burg, Alexios Konstantinos Balatsoukas Stimming, Orion Afisiadis, Joachim Tobias Tapparel, Mathieu Pierre Xhonneux

Long Range (LoRa) is an emerging low-power wide-area network technology offering long-range wireless connectivity to Internet of Things (IoT) devices. For energy efficiency reasons, LoRa end nodes implement a nonslotted ALOHA multiple access scheme to tran ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Enhancing the Reliability of Dense LoRaWAN Networks With Multi-User Receivers

Andreas Peter Burg, Joachim Tobias Tapparel, Mathieu Pierre Xhonneux

LoRaWAN is a low-power wireless technology that provides long-range connectivity to battery-powered Internet of Things (IoT) devices. To minimize the energy consumption of the IoT nodes, LoRaWAN networks use for the uplink a pure non-slotted ALOHA multiple ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2021

On the Advantage of Coherent LoRa Detection in the Presence of Interference

Andreas Peter Burg, Alexios Konstantinos Balatsoukas Stimming, Orion Afisiadis, Joachim Tobias Tapparel, Sitian Li

It has been shown that the coherent detection of long range (LoRa) signals only provides marginal gains of around 0.7 dB on the additive white Gaussian noise (AWGN) channel. However, ALOHA-based massive Internet-of-Things systems, including LoRa, often ope ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2021

An Open-Source LoRa Physical Layer Prototype on GNU Radio

Andreas Peter Burg, Alexios Konstantinos Balatsoukas Stimming, Orion Afisiadis, Joachim Tobias Tapparel, Paul Angelin Antoine Mayoraz

LoRa is the proprietary physical layer (PHY) of LoRaWAN, which is a popular Internet-of-Things (IoT) protocol enabling low-power devices to communicate over long ranges. A number of reverse engineering attempts have been published in the last few years tha ...

IEEE2020

A Maximum-Likelihood-based Multi-User LoRa Receiver Implemented in GNU Radio

Andreas Peter Burg, Alexios Konstantinos Balatsoukas Stimming, Orion Afisiadis, Joachim Tobias Tapparel, Mathieu Pierre Xhonneux

LoRa is a popular low-power wide-area network (LPWAN) technology that uses spread-spectrum to achieve long-range connectivity and resilience to noise and interference. For energy efficiency reasons, LoRa adopts a pure ALOHA access scheme, which leads to re ...

IEEE2020