In this letter, we focus on the evaluation of link-level performance of LoRa technology, in the usual network scenario with a central gateway and high-density deployment of end-devices. LoRa technology achieves wide coverage areas, low power consumption and robustness to interference thanks to a chirp spread-spectrum modulation, in which chirps modulated with different spreading factors (SFs) are quasi-orthogonal. We focus on the performance analysis of a single receiver in presence of collisions. First, we analyze LoRa modulation numerically and show that collisions between packets modulated with different SFs can indeed cause packet loss if the interference power received is strong enough. Second, we validate such findings in experiments based on commercial devices and software-defined radios. Contradicting the common belief that SFs can be considered orthogonal, our results demonstrate that inter-SF collisions are indeed an issue in LoRa networks and, thus, allocating higher SFs to users far from the gateway might not necessarily improve their link capacity, in case of congested networks.

Daniele Croce, M.G. (2018). Impact of LoRa Imperfect Orthogonality: Analysis of Link-Level Performance. IEEE COMMUNICATIONS LETTERS, 22(4), 796-799 [10.1109/LCOMM.2018.2797057].

Impact of LoRa Imperfect Orthogonality: Analysis of Link-Level Performance

Daniele Croce
;
Michele Gucciardo;Stefano Mangione;Giuseppe Santaromita;Ilenia Tinnirello
2018-01-01

Abstract

In this letter, we focus on the evaluation of link-level performance of LoRa technology, in the usual network scenario with a central gateway and high-density deployment of end-devices. LoRa technology achieves wide coverage areas, low power consumption and robustness to interference thanks to a chirp spread-spectrum modulation, in which chirps modulated with different spreading factors (SFs) are quasi-orthogonal. We focus on the performance analysis of a single receiver in presence of collisions. First, we analyze LoRa modulation numerically and show that collisions between packets modulated with different SFs can indeed cause packet loss if the interference power received is strong enough. Second, we validate such findings in experiments based on commercial devices and software-defined radios. Contradicting the common belief that SFs can be considered orthogonal, our results demonstrate that inter-SF collisions are indeed an issue in LoRa networks and, thus, allocating higher SFs to users far from the gateway might not necessarily improve their link capacity, in case of congested networks.
Settore ING-INF/03 - Telecomunicazioni
Daniele Croce, M.G. (2018). Impact of LoRa Imperfect Orthogonality: Analysis of Link-Level Performance. IEEE COMMUNICATIONS LETTERS, 22(4), 796-799 [10.1109/LCOMM.2018.2797057].
File in questo prodotto:
File Dimensione Formato  
LoRa_commlet.pdf

Solo gestori archvio

Descrizione: Articolo principale
Tipologia: Versione Editoriale
Dimensione 703.02 kB
Formato Adobe PDF
703.02 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
08267219.pdf

accesso aperto

Tipologia: Post-print
Dimensione 411.64 kB
Formato Adobe PDF
411.64 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/301652
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 230
  • ???jsp.display-item.citation.isi??? 185
social impact