Dual-Mode Time Domain Multiplexed Chirp Spread Spectrum

Ali Waqar Azim; Ahmad Bazzi; Mahrukh Fatima; Raed Shubair; Marwa Chafii

doi:10.1109/TVT.2023.3295270

Dual-Mode Time Domain Multiplexed Chirp Spread Spectrum

Ali Waqar Azim, Ahmad Bazzi, Mahrukh Fatima, Raed Shubair, Marwa Chafii

Computer Engineering

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

Abstract

In this work, we introduce dual-mode (DM) time domain multiplexed (TDM) chirp spread spectrum (CSS), which offers improved spectral and energy efficiency for low-power wide-Area networks (LPWANs). Previous work on LPWANs has proposed DM-CSS modulation using even and odd frequency shifts (FSs) to enhance performance over classical approaches. However, its spectral efficiency is only half that of the in-phase and quadrature (IQ)-TDM-CSS scheme, which employs IQ components with both up and down chirps, resulting in a four times higher SE of Long Range (LoRa). IQ-TDM-CSS only supports coherent detection and is sensitive to the carrier frequency and phase offsets. It makes it less practical for low-cost battery-powered LPWANs in Internet-of-Things (IoT) applications. In contrast, DM-CSS utilizes either an up-chirp or a down-chirp and consists of two chirped symbols that are multiplexed in the time domain. One of these symbols is chirped using an up-chirp and comprises even and odd FSs. The second chirped symbol is also composed of even and odd FSs, which are chirped using a down-chirp. We demonstrate that DM-TDM-CSS achieves a maximum achievable SE close to IQ-TDM-CSS while supporting both coherent and non-coherent detection. Moreover, unlike IQ-TDM-CSS, DM-TDM-CSS is robust against carrier frequency and phase offsets, making it more suitable for low-cost, battery-powered LPWANs in IoT applications.

Original language	English (US)
Pages (from-to)	16086-16097
Number of pages	12
Journal	IEEE Transactions on Vehicular Technology
Volume	72
Issue number	12
DOIs	https://doi.org/10.1109/TVT.2023.3295270
State	Published - Dec 1 2023

Keywords

IoT
LoRa
chirp spread spectrum

ASJC Scopus subject areas

Aerospace Engineering
Electrical and Electronic Engineering
Computer Networks and Communications
Automotive Engineering

Access to Document

10.1109/TVT.2023.3295270

Cite this

@article{0d3bd1b72492430f9de5339f6e349f05,

title = "Dual-Mode Time Domain Multiplexed Chirp Spread Spectrum",

abstract = "In this work, we introduce dual-mode (DM) time domain multiplexed (TDM) chirp spread spectrum (CSS), which offers improved spectral and energy efficiency for low-power wide-Area networks (LPWANs). Previous work on LPWANs has proposed DM-CSS modulation using even and odd frequency shifts (FSs) to enhance performance over classical approaches. However, its spectral efficiency is only half that of the in-phase and quadrature (IQ)-TDM-CSS scheme, which employs IQ components with both up and down chirps, resulting in a four times higher SE of Long Range (LoRa). IQ-TDM-CSS only supports coherent detection and is sensitive to the carrier frequency and phase offsets. It makes it less practical for low-cost battery-powered LPWANs in Internet-of-Things (IoT) applications. In contrast, DM-CSS utilizes either an up-chirp or a down-chirp and consists of two chirped symbols that are multiplexed in the time domain. One of these symbols is chirped using an up-chirp and comprises even and odd FSs. The second chirped symbol is also composed of even and odd FSs, which are chirped using a down-chirp. We demonstrate that DM-TDM-CSS achieves a maximum achievable SE close to IQ-TDM-CSS while supporting both coherent and non-coherent detection. Moreover, unlike IQ-TDM-CSS, DM-TDM-CSS is robust against carrier frequency and phase offsets, making it more suitable for low-cost, battery-powered LPWANs in IoT applications.",

keywords = "IoT, LoRa, chirp spread spectrum",

author = "Azim, {Ali Waqar} and Ahmad Bazzi and Mahrukh Fatima and Raed Shubair and Marwa Chafii",

note = "Publisher Copyright: {\textcopyright} 1967-2012 IEEE.",

year = "2023",

month = dec,

day = "1",

doi = "10.1109/TVT.2023.3295270",

language = "English (US)",

volume = "72",

pages = "16086--16097",

journal = "IEEE Transactions on Vehicular Technology",

issn = "0018-9545",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

number = "12",

}

TY - JOUR

T1 - Dual-Mode Time Domain Multiplexed Chirp Spread Spectrum

AU - Azim, Ali Waqar

AU - Bazzi, Ahmad

AU - Fatima, Mahrukh

AU - Shubair, Raed

AU - Chafii, Marwa

PY - 2023/12/1

Y1 - 2023/12/1

N2 - In this work, we introduce dual-mode (DM) time domain multiplexed (TDM) chirp spread spectrum (CSS), which offers improved spectral and energy efficiency for low-power wide-Area networks (LPWANs). Previous work on LPWANs has proposed DM-CSS modulation using even and odd frequency shifts (FSs) to enhance performance over classical approaches. However, its spectral efficiency is only half that of the in-phase and quadrature (IQ)-TDM-CSS scheme, which employs IQ components with both up and down chirps, resulting in a four times higher SE of Long Range (LoRa). IQ-TDM-CSS only supports coherent detection and is sensitive to the carrier frequency and phase offsets. It makes it less practical for low-cost battery-powered LPWANs in Internet-of-Things (IoT) applications. In contrast, DM-CSS utilizes either an up-chirp or a down-chirp and consists of two chirped symbols that are multiplexed in the time domain. One of these symbols is chirped using an up-chirp and comprises even and odd FSs. The second chirped symbol is also composed of even and odd FSs, which are chirped using a down-chirp. We demonstrate that DM-TDM-CSS achieves a maximum achievable SE close to IQ-TDM-CSS while supporting both coherent and non-coherent detection. Moreover, unlike IQ-TDM-CSS, DM-TDM-CSS is robust against carrier frequency and phase offsets, making it more suitable for low-cost, battery-powered LPWANs in IoT applications.

AB - In this work, we introduce dual-mode (DM) time domain multiplexed (TDM) chirp spread spectrum (CSS), which offers improved spectral and energy efficiency for low-power wide-Area networks (LPWANs). Previous work on LPWANs has proposed DM-CSS modulation using even and odd frequency shifts (FSs) to enhance performance over classical approaches. However, its spectral efficiency is only half that of the in-phase and quadrature (IQ)-TDM-CSS scheme, which employs IQ components with both up and down chirps, resulting in a four times higher SE of Long Range (LoRa). IQ-TDM-CSS only supports coherent detection and is sensitive to the carrier frequency and phase offsets. It makes it less practical for low-cost battery-powered LPWANs in Internet-of-Things (IoT) applications. In contrast, DM-CSS utilizes either an up-chirp or a down-chirp and consists of two chirped symbols that are multiplexed in the time domain. One of these symbols is chirped using an up-chirp and comprises even and odd FSs. The second chirped symbol is also composed of even and odd FSs, which are chirped using a down-chirp. We demonstrate that DM-TDM-CSS achieves a maximum achievable SE close to IQ-TDM-CSS while supporting both coherent and non-coherent detection. Moreover, unlike IQ-TDM-CSS, DM-TDM-CSS is robust against carrier frequency and phase offsets, making it more suitable for low-cost, battery-powered LPWANs in IoT applications.

KW - IoT

KW - LoRa

KW - chirp spread spectrum

UR - http://www.scopus.com/inward/record.url?scp=85164832155&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85164832155&partnerID=8YFLogxK

U2 - 10.1109/TVT.2023.3295270

DO - 10.1109/TVT.2023.3295270

M3 - Article

AN - SCOPUS:85164832155

SN - 0018-9545

VL - 72

SP - 16086

EP - 16097

JO - IEEE Transactions on Vehicular Technology

JF - IEEE Transactions on Vehicular Technology

IS - 12

ER -

Dual-Mode Time Domain Multiplexed Chirp Spread Spectrum

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this