This page is still under development and the experiment described on this page is not yet generally available.
1) Experiment Overview
Experiment Definition: This experiment is a GNU Radio-based LoRa signal transmission between two AERPAW nodes, with one node acting as a transmitter and one node acting as a receiver. The experiment transmits a text message between two LoRa nodes. At the end of the experiment, the user can view test results from a file called output.txt.
Experiment Scenarios Applicable: S1, S2, S3, S4, S7, S8, S9, S10, S11. These scenarios correspond to the various user experimentation scenarios in AERPAW.
Experiment Goals: A fully functional GNU Radio software-defined radio (SDR) implementation of a LoRa transceiver with all the necessary receiver components to operate correctly even at very low SNRs [1]. A LoRa PHY modulated text message is transmitted from the transmitter node using GNURadio with LoRa PHY parameters that can be modified by the user.
Experiment Modes: Different modes offered in this experiment are TESTBED and EMULATION. The EMULATION mode is performed in the development environment by the experimenter. The experimenter can modify the code. In TESTBED mode performed by the operator the transmitter and receiver are connected to a USRP B205mini and the transmission and reception occur over the air.
USRP Center Frequency
LoRa Code Rate
LoRa Spreading Factor
LoRa Signal Bandwidth
USRP TX/RX Gain
Transmitted Message
2) Performing the Experiment:
Transmitter
The transmitter may be a fixed node or a portable node. Login to the E-VM corresponding to the fixed node. Navigate to the folder containing all the Radio scripts
$ cd /root/Profiles/ProfileScripts/Radio
Copy the LoRa transmitter script as lora-TX.sh
$ cp Samples/loraGNURadio-TX.sh lora-TX.sh
In the command line, run the file stepaths.sh
$ . setpaths.sh
Start the LoRa transmitter by running the following command:
$ . lora-TX.sh
Receiver
The receiver may be a fixed node or a portable node. Login to the E-VM corresponding to the fixed node. Navigate to the folder containing all the Radio scripts
$ cd /root/Profiles/ProfileScripts/Radio
Copy the LoRa transmitter script as lora-TX.sh
$ cp Samples/loraGNURadio-RX.sh lora-RX.sh
In the command line, run the file sethpaths.sh
$ . setpaths.sh
Start the LoRa receiver by running the following command:
$ . lora-RX.sh
3) Modifying the Experiment Configuration Parameters:
Transmitter:
The shell script /root/Profiles/ProfileScripts/Radio/profileLoRaTX.sh calls the script /root/Profiles/ProfileScripts/Radio/Helpers/LoRaTXGRC.sh which can be edited by the experimenter to modify the parameters of the transmitter
Receiver:
The shell script /root/Profiles/ProfileScripts/Radio/profileLoRaRX.sh calls the script /root/Profiles/ProfileScripts/Radio/Helpers/LoRaRXGRC.sh which can be edited by the experimenter to modify the parameters of the receiver
4) Results:
The experiment transmits a text message using LoRa PHY modulation from the transmitter node to the receiver node. The received messages are stored in the file called output.txt. Performance measures such as received signal strength at a given GPS location may be added to the code.
References
[1] J. Tapparel, O. Afisiadis, P. Mayoraz, A. Balatsoukas-Stimming, and A. Burg, “An Open-Source LoRa Physical Layer Prototype on GNU Radio”