TY - JOUR
T1 - On the LoRa Modulation for IoT: Waveform Properties and Spectral Analysis
AU - chiani, Marco
AU - Elzanaty, Ahmed Mohamed
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported in part by MIUR under the program “Dipartimenti di Eccellenza (2018-2022),” and in part by the EU project eCircular (EIT Climate-KIC).
PY - 2019
Y1 - 2019
N2 - An important modulation technique for Internet of Things (IoT) is the one proposed by the LoRa allianceTM. In this paper we analyze the M-ary LoRa modulation in the time and frequency domains. First, we provide the signal description in the time domain, and show that LoRa is a memoryless continuous phase modulation. The cross-correlation between the transmitted waveforms is determined, proving that LoRa can be considered approximately an orthogonal modulation only for large M. Then, we investigate the spectral characteristics of the signal modulated by random data, obtaining a closed-form expression of the spectrum in terms of Fresnel functions. Quite surprisingly, we found that LoRa has both continuous and discrete spectra, with the discrete spectrum containing exactly a fraction 1/M of the total signal power.
AB - An important modulation technique for Internet of Things (IoT) is the one proposed by the LoRa allianceTM. In this paper we analyze the M-ary LoRa modulation in the time and frequency domains. First, we provide the signal description in the time domain, and show that LoRa is a memoryless continuous phase modulation. The cross-correlation between the transmitted waveforms is determined, proving that LoRa can be considered approximately an orthogonal modulation only for large M. Then, we investigate the spectral characteristics of the signal modulated by random data, obtaining a closed-form expression of the spectrum in terms of Fresnel functions. Quite surprisingly, we found that LoRa has both continuous and discrete spectra, with the discrete spectrum containing exactly a fraction 1/M of the total signal power.
UR - http://hdl.handle.net/10754/655888
UR - https://ieeexplore.ieee.org/document/8723130/
U2 - 10.1109/JIOT.2019.2919151
DO - 10.1109/JIOT.2019.2919151
M3 - Article
SN - 2327-4662
VL - 6
SP - 8463
EP - 8470
JO - IEEE Internet of Things Journal
JF - IEEE Internet of Things Journal
IS - 5
ER -