@techreport{asw-lrlfs-26,
  title = {LZn : Robust LoRa Frame Synchronization Under Frame Collisions and Ultra-Low SNR Conditions},
  author = {Jose Álamos and Thomas C. Schmidt and Matthias W{\"a}hlisch},
  institution = {Open Archive: arXiv.org},
  year = {2026},
  month = {April},
  type = {Technical Report},
  number = {2604.27672},
  abstract = {LoRa has become a widely adopted wireless modulation scheme in LPWANs due to its low cost, long range, and minimal transmission power. However, collisions between frames of the same spreading factor -- common in dense LoRa deployments -- prevent conventional LoRa receivers from detecting and correctly decoding frames. Recent work has introduced methods to improve recovery, yet their detection stage degrades sharply under low signal-to-noise ratio (SNR) and high collision rates. In this work, we introduce LZn, a low-complexity synchronization scheme driven by a spectral intersection operation. Our method enables robust frame synchronization even under multiple packet overlaps or extremely low SNR conditions. We evaluate LZn on simulations and three independent, real-world LoRa datasets. LZn improves detection sensitivity by up to 10dB and increases detection probability by up to 1.54x. In real-world datasets, LZn improves decoding by 3.46x in the most challenging single-user scenario and up to 1.22x in collision scenarios compared to the second best collision-tolerant scheme (TnB). These results demonstrate that LZn substantially improves the frame recovery of LoRa receivers, while remaining compatible with real-time requirements.},
  file = {https://arxiv.org/pdf/2604.27672},
  theme = {iot},
}