Frequency-hopped multi-user chirp modulation (FH/M-CM) for multipath fading channels

El‐Khamy, Said E.; Shaaban, Shawki; Thabet, E.A.

doi:10.1109/nrsc.1999.760890

Cited by 15 publications

(5 citation statements)

References 8 publications

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“…proprietary LoRa modulation relies on a chirp spread spectrum technique, which has proven to be resilient to multi-path interference and channel fading. 16 It allows transmissions to reach up to 10 km ranges under ideal conditions, 3 with a relatively low power operation. A key parameter of this technique is the spreading factor (SF), that can be associated to the chirp sweeping time.…”

Section: Background On Lora and Lorawanmentioning

confidence: 99%

“…The term LoRa specifically designates the physical layer, while LoRaWAN is the MAC layer that was designed on the top of it. The proprietary LoRa modulation relies on a chirp spread spectrum technique, which has proven to be resilient to multi‐path interference and channel fading 16 . It allows transmissions to reach up to 10 km ranges under ideal conditions, 3 with a relatively low power operation.…”

Section: Background On Lora and Lorawanmentioning

confidence: 99%

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LoRaSync: Energy efficient synchronization for scalable LoRaWAN

Chasserat,

Accettura,

Berthou

2024

Trans Emerging Tel Tech

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Low‐power wide‐area networks connect a large number of battery‐powered wireless devices over long distances. Among them, long range wide area networks (LoRaWAN) implement a pure ALOHA medium access scheme to save device energy by minimizing the radio usage. However, frame collisions restrain the network scalability when the traffic load increases. In this context, synchronization can be used to exploit the available bandwidth more efficiently by controlling the timing of frame transmissions and reducing the collision probability. Such strategy allows to increase the network throughput at the cost of an extra energy demand due to the inherent overhead. In that, the entailed network scenario is still supposed to address low power applications. Therefore this article timely presents LoRaSync, an energy‐efficient synchronization scheme designed for LoRa networks of any size. An accurate clock drift model was established based on measurements made on real cheap devices, and leveraged to support the design of LoRaSync. Our mechanism has been used to evaluate the same ALOHA‐based random access but on a time‐slotted basis, thus increasing the maximum achievable throughput compared to the legacy access. Throughput and energy efficiency models are established to evaluate the performances of a LoRaSync‐operated network. These models are validated with a simulation environment mimicking large‐scale deployments, and then used to determine the most energy efficient slot size for any traffic load. As a final proof of concept, LoRaSync has been implemented and tested on a LoRa testbed to demonstrate the feasibility of our solution on real hardware.

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Section: Background On Lora and Lorawanmentioning

confidence: 99%

Section: Background On Lora and Lorawanmentioning

confidence: 99%

LoRaSync: Energy efficient synchronization for scalable LoRaWAN

Chasserat,

Accettura,

Berthou

2024

Trans Emerging Tel Tech

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“…The key advantages of LoRaWAN over traditional approaches such as Wi-Fi and GSM-based methods, are high resilience to multi-path fading over long distances [10], [11], and the ability to choose power consumption to be low or high, in line with the specific use cases [12]. This goal is achieved through a proprietary modulation owned by Semtech [13], that relies on the Chirp Spread Spectrum (CSS) technique [14]. However, LoRaWAN is relatively new, which leads to low adoption rate and availability of infrastructure, especially outside of USA and Europe.…”

Section: Introductionmentioning

confidence: 99%

Feasibility of Standalone TDoA-based Localization Using LoRaWAN

Muppala

Navnit

Devendra

et al. 2021

2021 International Conference on Localization and GNSS (ICL-GNSS)

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The growing need for localization has created an array of alternative approaches to GNSS, based on Wi-Fi, Bluetooth, Ultra-Wideband, etc. Long Range Wide Area Network (LoRaWAN) is one such technology that has garnered tremendous attention due to its low power and long-range capabilities. Many attempts to achieve localization using LoRaWAN have been made till now, based on a variety of techniques such as Angle of Arrival (AoA), Time Difference of Arrival (TDoA), Received Signal Strength Index (RSSI). In this paper, we present a novel, standalone localization approach by developing a collaborative, TDoA-based methodology using LoRaWAN. The server determines the target node location by means of TDoA measurements from the target node to the gateways. The introduction of an additional stationary node allows the synchronization of the gateways without utilizing GNSS, either inbuilt or external. The cooperation between target node, synchronization node and server, is the innovative feature which makes this approach attractive for GNSS-free localization. Further, we explore the effects of timing resolution, time-on-air, and duty cycle constraints on the localization error. Finally, the distribution of error in a triangle of gateways situated approximately 8.6 kilometers apart is simulated in ideal Line of Sight (LoS) conditions, showing the maximum error to be around 23 meters.

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“…El-Khamy et al [5] presented new forms of chirp signals for binary multi-user communication which are characterized by the same power and the same bandwidth. In [6], they investigated the combination of frequency hopping (FH) spread spectrum techniques with multi-user chirp modulation to produce a multiple access technique that is characterized by good performance in dispersive and fading channels. This hybrid spread spectrum technique improves communication system Said performance especially in multipath fading dispersive channels.…”

Section: Introductionmentioning

confidence: 99%

Performance of Wide Band Multi-User Frequency Hopping Chaotic Chirp Modulation (FH/MCCM) In Multipath Dispersive Media

El‐Khamy

Shaaban

Thabet

2005

EUROCON 2005 - The International Conference on "Computer as a Tool"

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New forms of multi-user chaotic chirp modulation (MCCM) signals that are characterized by the same power as well as the same bandwidth are introduced in this paper. The combination of frequency hopping spread spectrum (FHSS) techniques with (MCCM) is investigated to design a multiple-access technique that is characterized by good performance in dispersive and fading propagation media as well as reduced multiple-access interference (MAI). The new suggested frequency-hopped multi-user chaotic chirp modulation (FH/MCCM) is investigated in detail and its performance is shown to outperform that of (MCCM). Chaotic Carrier Frequency Hopping (CCFH) is used where the hopping is according to a chaotic map. Also, a novel Chaotic Slope Fast Hopping (CSFH) is also considered in which each user generate a chirp signal with a chaotic linear frequency sweeping slope.

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Frequency-hopped multi-user chirp modulation (FH/M-CM) for multipath fading channels

Cited by 15 publications

References 8 publications

LoRaSync: Energy efficient synchronization for scalable LoRaWAN

LoRaSync: Energy efficient synchronization for scalable LoRaWAN

Feasibility of Standalone TDoA-based Localization Using LoRaWAN

Performance of Wide Band Multi-User Frequency Hopping Chaotic Chirp Modulation (FH/MCCM) In Multipath Dispersive Media

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