Quasisynchronous LoRa for LEO Nanosatellite Communications


Creative Commons License

Uysal H. G., Yılmaz F., Çırpan H. A., Kucur O., ARSLAN H.

2023 IEEE International Black Sea Conference on Communications and Networking, BlackSeaCom 2023, İstanbul, Turkey, 4 - 07 July 2023, pp.181-185 identifier

  • Publication Type: Conference Paper / Full Text
  • Doi Number: 10.1109/blackseacom58138.2023.10299744
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.181-185
  • Keywords: LoRa, performance analysis, quasisynchronous LoRa, symbol error rate
  • Istanbul Medipol University Affiliated: Yes

Abstract

Perfect synchronization in LoRa communications between Low Earth Orbit (LEO) satellites and ground base stations is still challenging, despite the potential use of atomic clocks in LEO satellites, which offer high precision. Even by incorporating atomic clocks in LEO satellites, their inherent precision can be leveraged to enhance the overall synchronization process, perfect synchronization is infeasible due to a combination of factors such as signal propagation delay, Doppler effects, clock drift and atmospheric effects. These challenges require the development of advanced synchronization techniques and algorithms to mitigate their effects and ensure reliable communication from / to LEO satellites. However, maintaining acceptable levels of synchronization rather than striving for perfection, quasisynchronous (QS) communication can be adopted which maintains communication reliability, improves resource utilization, reduces power consumption, and ensures scalability as more devices join the communication. Overall, QS communication offers a practical, adaptive, and robust solution that enables LEO satellite communications to support the growing demands of IoT applications and global connectivity. In our investigation, we explore different chip waveforms such as rectangular and raised cosine. Furthermore, for the first time, we study the Symbol Error Rate (SER) performance of QS LoRa communication, for different spreading factors (SF), over Additive White Gaussian Noise (AWGN) channels.