Unsourced random access: a comprehensive survey
File(s)
Accepted version
Author(s)
Ozates, Mert
Javad Ahmadi, Mohammad
Kazemi, Mohammad
Gündüz, Deniz
Duman, Tolga M
Type
Journal Article
Abstract
Multiple access communication systems enable numerous users to share common communication resources, playing a crucial role in wireless networks. With the emergence of the sixth generation (6G) and beyond communication networks, supporting massive machine-type communications with sporadic activity patterns is expected to become a critical challenge. Unsourced random access (URA) has emerged as a promising paradigm to address this challenge by decoupling user identification from data transmission through the use of a common codebook. This survey offers a comprehensive overview of URA solutions, encompassing both theoretical foundations and practical applications. We present a systematic classification of URA solutions across three primary channel models: Gaussian multiple access channels (GMACs), single-antenna fading channels, and multiple-input multiple-output (MIMO) fading channels. For each category, we analyze and compare state-of-the-art solutions in terms of performance, complexity, and practical feasibility. Additionally, we discuss critical challenges such as interference management, computational complexity, and synchronization. The survey concludes with promising future research directions and potential methods to address existing limitations, providing a roadmap for researchers and practitioners in this rapidly evolving field.
Date Issued
2026-01-01
Date Acceptance
2025-11-14
Citation
IEEE Communications Surveys and Tutorials, 2026, 28, pp.955-984
ISSN
1553-877X
Publisher
Institute of Electrical and Electronics Engineers
Start Page
955
End Page
984
Journal / Book Title
IEEE Communications Surveys and Tutorials
Volume
28
Copyright Statement
Copyright © 2026 IEEE. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Publication Status
Published
Date Publish Online
2025-11-26