A Low-Complexity LoRa Synchronization Algorithm Robust to Sampling Time Offsets

LoRaWAN is nowadays one of the most popular protocols for low-power Internet Things communications. Although its physical layer, namely LoRa, has been thoroughly studied in literature, aspects related to synchronization LoRa receivers have received little attention so far. The estimation and correction carrier frequency sampling time offsets (STOs) are, however, crucial attain low sensitivity levels offered by spread-spectrum modulation. goal this article build a low-complexity, yet efficient algorithm capable correcting both offsets. To end, complete analytical model signal corrupted these first derived. Using model, we propose new estimator STO. We also show that estimations STOs cannot be performed independently. Therefore, avoid complex joint offsets, an iterative low-complexity proposed. reach packet error rate 10 ?3 , performance evaluations proposed receiver requires only 1 or 2 dB higher signal-to-noise ratio than theoretical perfectly synchronized receiver, while incurring very computational overhead.