Psychoanalysis

Software-defined radio

Open source

Embedded system

Layer (electronics)

Real-time computing

Operating system

Telecommunications

Computer science

Computer network

Software

Offset (computer science)

Organic chemistry

Psychology

Orthogonal frequency-division multiplexing

Frequency offset

Physical layer

Chemistry

Channel (broadcasting)

Wireless

Compensation (psychology)

Carrier frequency offset

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 that helped to reveal many of the LoRa PHY details. In this work, we describe our standard-compatible LoRa PHY software-defined radio (SDR) prototype based on GNU Radio. We show how this SDR prototype can be used to develop and evaluate receiver algorithms for LoRa. As an example, we describe the sampling time offset and the carrier frequency offset estimation and compensation blocks. We experimentally evaluate the error rate of LoRa, both for the uncoded and the coded cases, to illustrate that our publicly available open-source implementation is a solid basis for further research.

An Open-Source LoRa Physical Layer Prototype on GNU Radio