Energy-efficient random access for leo satellite-assisted 6G internet of remote things

Li Zhen, Ali Kashif Bashir, Keping Yu*, Yasser D. Al-Otaibi, Chuan Heng Foh, Pei Xiao

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

105 Citations (Scopus)


Satellite communication system is expected to play a vital role for realizing various remote Internet-of-Things (IoT) applications in sixth-generation vision. Due to unique characteristics of satellite environment, one of the main challenges in this system is to accommodate massive random access (RA) requests of IoT devices while minimizing their energy consumptions. In this article, we focus on the reliable design and detection of RA preamble to effectively enhance the access efficiency in high-dynamic low-earth-orbit (LEO) scenarios. To avoid additional signaling overhead and detection process, a long preamble sequence is constructed by concatenating the conjugated and circularly shifted replicas of a single root Zadoff-Chu (ZC) sequence in RA procedure. Moreover, we propose a novel impulse-like timing metric based on length-alterable differential cross-correlation (LDCC), that is immune to carrier frequency offset (CFO) and capable of mitigating the impact of noise on timing estimation. Statistical analysis of the proposed metric reveals that increasing correlation length can obviously promote the output signal-to-noise power ratio, and the first-path detection threshold is independent of noise statistics. Simulation results in different LEO scenarios validate the robustness of the proposed method to severe channel distortion, and show that our method can achieve significant performance enhancement in terms of timing estimation accuracy, success probability of first access, and mean normalized access energy, compared with the existing RA methods.

Original languageEnglish
Article number9222142
Pages (from-to)5114-5128
Number of pages15
JournalIEEE Internet of Things Journal
Issue number7
Publication statusPublished - 2021 Apr 1


  • Energy efficiency
  • Internet of remote things
  • random access (RA)
  • satellite communication
  • sixth generation (6G)

ASJC Scopus subject areas

  • Signal Processing
  • Information Systems
  • Hardware and Architecture
  • Computer Science Applications
  • Computer Networks and Communications


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