{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/massive-uncoordinated-access-with-random-user","title":"Massive Uncoordinated Access With Random User Activity","arxiv_id":"2103.09721","date":"2021-03-17","proceeding":null,"authors":["Khac-Hoang Ngo","Alejandro Lancho","Giuseppe Durisi","Alexandre Graell i Amat"],"abstract":"We extend the seminal work by Polyanskiy (2017) on massive uncoordinated access to the case where the number of active users is random and unknown a priori. We define a random-access code accounting for both misdetection (MD) and false alarm (FA), and derive a random-coding achievability bound for the Gaussian multiple-access channel. Our bound captures the fundamental trade-off between MD and FA probabilities. The derived bound suggests that, for the scenario considered in Polyanskiy (2017), lack of knowledge of the number of active users entails a small penalty in terms of power efficiency. For example, our bound shows that 0.5-0.7 dB extra power is required to achieve both MD and FA probabilities below 0.1 compared to the case in which the number of active users is known a priori. Taking both MD and FA into account, we show that some of the recently proposed massive random access schemes are highly suboptimal with respect to our bound.","url_abs":"https://arxiv.org/abs/2103.09721v2","url_pdf":"https://arxiv.org/pdf/2103.09721v2.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"massive-uncoordinated-access-with-random-user","repo_url":"https://github.com/khachoang1412/uma_random_user_activity","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}