SCLoRa: Leveraging Multi-Dimensionality in Decoding Collided LoRa Transmissions

Hu, Bin; Yin, Zhimeng; Wang, Shuai; Xu, Zhuqing; He, Tian

doi:10.1109/icnp49622.2020.9259397

Cited by 43 publications

(15 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Prior work on resolving LoRa collisions has followed a common theme: exploring the unique features of collided LoRa symbols in the time domain [34,35,39], frequency domain [9,28,30,36], or both [15,27]. For instance, mLoRa [34] observes that collisions usually start with a stretch of interference free bits on the packet header.…”

Section: Related Workmentioning

confidence: 99%

“…Let S R be their • Case one: when both S A and S B are linear chirps, we are expected to see two separate energy peaks on FFT bins (shown in Figure 11(a)). In this case, all existing parallel decoding approaches [9,15,28,30,[34][35][36]39] fail to disambiguate the collision symbols as these two well-aligned symbols exhibit similar FFT peaks.…”

Section: Modulationmentioning

confidence: 99%

See 1 more Smart Citation

CurvingLoRa to Boost LoRa Network Capacity via Concurrent Transmission

Li¹,

Guo²,

Shangguan³

et al. 2022

Preprint

View full text Add to dashboard Cite

LoRaWAN has emerged as an appealing technology to connect IoT devices but it functions without explicit coordination among transmitters, which can lead to many packet collisions as the network scales. State-of-the-art work proposes various approaches to deal with these collisions, but most functions only in high signal-to-interference ratio (SIR) conditions and thus does not scale to many scenarios where weak receptions are easily buried by stronger receptions from nearby transmitters. In this paper, we take a fresh look at LoRa's physical layer, revealing that its underlying linear chirp modulation fundamentally limits the capacity and scalability of concurrent LoRa transmissions. We show that by replacing linear chirps with their non-linear counterparts, we can boost the capacity of concurrent LoRa transmissions and empower the LoRa receiver to successfully receive weak transmissions in the presence of strong colliding signals. Such a non-linear chirp design further enables the receiver to demodulate fully aligned collision symbols -a case where none of the existing approaches can deal with. We implement these ideas in a holistic LoRaWAN stack based on the USRP N210 software-defined radio platform. Our head-to-head comparison with two stateof-the-art research systems and a standard LoRaWAN baseline demonstrates that CurvingLoRa improves the network throughput by 1.6-7.6× while simultaneously sacrificing neither power efficiency nor noise resilience. An open-source dataset and code will be made available before publication.

show abstract

Section: Related Workmentioning

confidence: 99%

Section: Modulationmentioning

confidence: 99%

CurvingLoRa to Boost LoRa Network Capacity via Concurrent Transmission

Li¹,

Guo²,

Shangguan³

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…In [23], the different frequency offsets between the users are used to distinguish their symbols. In [24], the received power of each user is also leveraged for the decision, whereas in [25], both the time and frequency offsets between users are used. The authors of [26] propose a scaled despreading operation that allows a more robust estimation of the time offset between the colliding users and hence of their corresponding symbols.…”

Section: B Multi-user Receivers For Dense Lorawan Networkmentioning

confidence: 99%

Enhancing the Reliability of Dense LoRaWAN Networks With Multi-User Receivers

Tapparel

Xhonneux

Bol

et al. 2021

IEEE Open J. Commun. Soc.

View full text Add to dashboard Cite

LoRaWAN is a low-power wireless technology that provides long-range connectivity to battery-powered Internet of things (IoT) devices. To minimize the energy consumption of the IoT nodes, LoRaWAN networks use for the uplink a pure non-slotted ALOHA multiple access scheme. Since the devices are not synchronized in time, collisions between uplink packets are the main source of errors when the number of nodes becomes important. To improve the reliability of dense LoRaWAN networks, we propose in this paper a successive interference cancellation LoRa receiver capable of decoding frames from two colliding users. The proposed two-user detector leverages the bit-interleaved coded modulation scheme of LoRa to improve the detection and cancellation of the strongest interfering user. We show that in the presence of two interfering users, the usage of a low coding-rate and iterative soft-detection are essential to attain error rates sufficiently close to the single-user scenario. Using network-level simulations, we subsequently evaluate the gains of our proposed two-user receiver in a realistic LoRaWAN network. To this end, we build advanced models of the studied receivers using Monte-Carlo simulations at the physical layer. For an overall packet error rate of 1%, simulation results indicate that a LoRaWAN network employing our two-user detector may serve 4.7 times more devices than a network with only a single-user receiver at the gateway.

show abstract

“…However, the offloading phase incurs excessive communication overhead and limits the large-scale application. We summarize the major performances of Standard LoRa [17], Conventional approach with specialized hardware, and Cloud-based approach in Table 1. In this paper, we ask a natural question that can we design an approach that achieves all the ideal performance at the same time, i.e., low data transmission amount, low computational complexity, high error correction capability and no extra hardware demand .…”

Section: Motivationsmentioning

confidence: 99%

“…Protocol-based Approaches. Early efforts on interference mitigation in LP-WANs have focused on solutions to physical, and MAC layers, including SCLoRa [17], Choir [23], FTrack [24], mLoRa [25], etc. in physical layer and S-MAC [26], LMAC [27], etc.…”

Section: Related Workmentioning

confidence: 99%

ECCR: Edge-Cloud Collaborative Recovery for Low-Power Wide-Area Networks interference mitigation

Mei¹,

Yin²,

Zhou³

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Recent advances in Low-Power Wide-Area Networks have mitigated interference by using cloud assistance. Those methods transmit the RSSI samples and corrupted packets to the cloud to restore the correct message. However, the effectiveness of those methods is challenged by the high transmission data amount. This paper presents a novel method for interference mitigation in a Edge-Cloud collaborative manner, namely ECCR. It does not require transmitting RSSI sample any more, whose length is eight times of the packet's. We demonstrate the disjointness of the bit errors of packets at the base stations via realword experiments. ECCR leverages this to collaborate with multiple base stations for error recovery. Each base station detects and reports bit error locations to the cloud, then both error checking code and interfered packets from other receivers are utilized to restore correct packets. ECCR takes the advantages of both the global management ability of the cloud and the signal to perceive the benefit of each base station, and it is applicable to deployed LP-WAN systems (e.g. sx1280) without any extra hardware requirement. Experimental results show that ECCR is able to accurately decode packets when packets have nearly 51.76% corruption.

show abstract

SCLoRa: Leveraging Multi-Dimensionality in Decoding Collided LoRa Transmissions

Cited by 43 publications

References 28 publications

CurvingLoRa to Boost LoRa Network Capacity via Concurrent Transmission

CurvingLoRa to Boost LoRa Network Capacity via Concurrent Transmission

Enhancing the Reliability of Dense LoRaWAN Networks With Multi-User Receivers

ECCR: Edge-Cloud Collaborative Recovery for Low-Power Wide-Area Networks interference mitigation

Contact Info

Product

Resources

About