Active User Identification in Fast Fading Massive Random Access Channels

Jyotish Robin, Elza Erkip

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Reliable and prompt identification of active users is critical for enabling random access in massive machine-to-machine type networks which typically operate within stringent access delay and energy constraints. In this paper, an energy efficient active user identification protocol is envisioned in which the active users simultaneously transmit On-Off Keying (OOK) modulated preambles whereas the base station uses non-coherent detection to avoid the channel estimation overheads. The minimum number of channel-uses required for active user identification in the asymptotic regime of total number of users ℓ when the number of active devices k scales as k = Θ(1) is characterized along with an achievability scheme relying on the equivalence of activity detection to a group testing problem. A practical scheme for active user identification based on a belief propagation strategy is also proposed and its performance is compared against the theoretical bounds.

Original languageEnglish (US)
Title of host publication2023 IEEE Information Theory Workshop, ITW 2023
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages6
ISBN (Electronic)9798350301496
StatePublished - 2023
Event2023 IEEE Information Theory Workshop, ITW 2023 - Saint-Malo, France
Duration: Apr 23 2023Apr 28 2023

Publication series

Name2023 IEEE Information Theory Workshop, ITW 2023


Conference2023 IEEE Information Theory Workshop, ITW 2023


  • IoT
  • active user identification
  • activity detection
  • group testing
  • massive random access

ASJC Scopus subject areas

  • Artificial Intelligence
  • Computational Theory and Mathematics
  • Computer Networks and Communications
  • Signal Processing
  • Control and Optimization


Dive into the research topics of 'Active User Identification in Fast Fading Massive Random Access Channels'. Together they form a unique fingerprint.

Cite this