On the LoRa Modulation for IoT: Waveform Properties and Spectral Analysis

Marco chiani; Ahmed Mohamed Elzanaty

doi:10.1109/JIOT.2019.2919151

On the LoRa Modulation for IoT: Waveform Properties and Spectral Analysis

Marco chiani, Ahmed Mohamed Elzanaty

Computer, Electrical and Mathematical Sciences and Engineering

Research output: Contribution to journal › Article › peer-review

175 Scopus citations

Abstract

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.

Original language	English (US)
Pages (from-to)	8463-8470
Number of pages	8
Journal	IEEE Internet of Things Journal
Volume	6
Issue number	5
DOIs	https://doi.org/10.1109/JIOT.2019.2919151
State	Published - 2019

Bibliographical note

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).

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10.1109/JIOT.2019.2919151

https://repository.kaust.edu.sa/bitstream/10754/655888/1/08723130.pdf

Cite this

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title = "On the LoRa Modulation for IoT: Waveform Properties and Spectral Analysis",

abstract = "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.",

author = "Marco chiani and Elzanaty, {Ahmed Mohamed}",

note = "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).",

year = "2019",

doi = "10.1109/JIOT.2019.2919151",

language = "English (US)",

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pages = "8463--8470",

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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/

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DO - 10.1109/JIOT.2019.2919151

M3 - Article

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SP - 8463

EP - 8470

JO - IEEE Internet of Things Journal

JF - IEEE Internet of Things Journal

IS - 5

ER -

On the LoRa Modulation for IoT: Waveform Properties and Spectral Analysis

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