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Related papers: Unsourced Random Access: A Comprehensive Survey

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Type-based unsourced multiple access (TUMA) is a recently proposed framework for type-based estimation in massive uncoordinated access networks. We extend the existing design of TUMA, developed for an additive white Gaussian channel, to a…

Information Theory · Computer Science 2025-04-29 Kaan Okumus , Khac-Hoang Ngo , Giuseppe Durisi , Erik G. Ström

This paper explores the fundamental limits of unsourced random access (URA) with a random and unknown number ${\rm{K}}_a$ of active users in MIMO quasi-static Rayleigh fading channels. First, we derive an upper bound on the probability of…

Information Theory · Computer Science 2024-04-16 Junyuan Gao , Yongpeng Wu , Giuseppe Caire , Wei Yang , Wenjun Zhang

This report summarizes some considerations on possible evolutions of grant-free random access in the next generation of the 3GPP wireless cellular standard. The analysis is carried out by mapping the problem to the recently-introduced…

We consider unsourced random access (uRA) in a cell-free (CF) user-centric wireless network, where a large number of potential users compete for a random access slot, while only a finite subset is active. The random access users transmit…

Information Theory · Computer Science 2025-05-01 Burak Çakmak , Eleni Gkiouzepi , Manfred Opper , Giuseppe Caire

This paper investigates the energy efficiency of massive unsourced random access~(URA) in multiple-input multiple-output quasi-static Rayleigh fading channels. Specifically, we derive achievability and converse bounds on the minimum…

Information Theory · Computer Science 2023-02-07 Junyuan Gao , Yongpeng Wu , Tianya Li , Wenjun Zhang

Unsourced random access (URA) is a recently proposed multiple access paradigm tailored to the uplink channel of machine-type communication networks. By exploiting a strong connection between URA and compressed sensing, the massive multiple…

Information Theory · Computer Science 2022-06-28 Jamison R. Ebert , Vamsi K. Amalladinne , Stefano Rini , Jean-Francois Chamberland , Krishna R. Narayanan

We consider an unsourced random access (URA) system enhanced with a feedback mechanism that serves both communication and sensing tasks. While traditional URA systems do not incorporate feedback, we propose a novel feedback signal design…

Information Theory · Computer Science 2025-06-26 Mohammad Javad Ahmadi , Mohammad Kazemi , Rafael F. Schaefer

In this paper, we propose a novel fully Bayesian approach for the massive multiple-input multiple-output (MIMO) massive unsourced random access (URA). The payload of each user device is coded by the sparse regression codes (SPARCs) without…

Information Theory · Computer Science 2023-06-28 Jia-Cheng Jiang , Hui-Ming Wang

We consider the problem of type estimation over unsourced multiple access fading channels in distributed multiple-input multiple-output (D-MIMO) systems. Unlike classical unsourced multiple access, type-based unsourced multiple access…

Information Theory · Computer Science 2026-03-03 Kaan Okumus , Khac-Hoang Ngo , Giuseppe Durisi , Erik G. Ström

In this paper we focus on a feedback mechanism for unsourced random access (URA) communications. We propose an algorithm to construct feedback packets broadcasted to the users by the base station (BS) as well as the feedback packet format…

Information Theory · Computer Science 2022-11-23 Murwan Bashir , Ehsan Nassaji , Dmitri Truhachev , Alireza Bayesteh , Monirosharieh Vameghestahbanati

This paper investigates asynchronous multiple-input multiple-output (MIMO) massive unsourced random access (URA) in an orthogonal frequency division multiplexing (OFDM) system over frequency-selective fading channels, with the presence of…

Information Theory · Computer Science 2024-10-24 Tianya Li , Yongpeng Wu , Junyuan Gao , Wenjun Zhang , Xiang-Gen Xia , Derrick Wing Kwan Ng , Chengshan Xiao

This paper considers the unsourced random access (URA) problem with a random and unknown number of active users in multiple-input multiple-output (MIMO) quasi-static Rayleigh fading channels. We derive non-asymptotic achievability bounds on…

Information Theory · Computer Science 2025-03-24 Junyuan Gao , Yongpeng Wu , Giuseppe Caire , Wei Yang , H. Vincent Poor , Wenjun Zhang

We investigate the coexistence of massive and critical Internet of Things (IoT) services in the context of the unsourced multiple access (UMA) framework introduced by Polyanskiy (2017), where all users employ a common codebook and the…

Information Theory · Computer Science 2023-10-16 Khac-Hoang Ngo , Giuseppe Durisi , Alexandre Graell i Amat , Petar Popovski , Anders E. Kalor , Beatriz Soret

We consider the unsourced random access problem with multiple receivers and propose a cell-free type solution for that. In our proposed scheme, the active users transmit their signals to the access points (APs) distributed in a geographical…

Emerging Technologies · Computer Science 2025-01-20 Mert Ozates , Mohammad Kazemi , Eduard Jorswieck , Deniz Gunduz

Unsourced random-access (U-RA) is a type of grant-free random access with a virtually unlimited number of users, of which only a certain number $K_a$ are active on the same time slot. Users employ exactly the same codebook, and the task of…

Information Theory · Computer Science 2021-01-11 Alexander Fengler , Peter Jung , Giuseppe Caire

In this paper, we design a novel two-phase unsourced random access (URA) scheme in massive multiple input multiple output (MIMO). In the first phase, we collect a sequence of information bits to jointly acquire the user channel state…

Information Theory · Computer Science 2023-06-28 Jia-Cheng Jiang , Hui-Ming Wang

This paper addresses the unsourced/uncoordinated random access problem in an integrated sensing and communications (ISAC) system, with a focus on uplink multiple access code design. Recent theoretical advancements highlight that an ISAC…

Information Theory · Computer Science 2025-04-25 Zhentian Zhang , Jian Dang , Kai-Kit Wong , Zaichen Zhang , Christos Masouros

We examine unsourced random access in a fully asynchronous setup, where active users transmit their data without restriction on the start time over a fading channel. In the proposed scheme, the transmitted signal consists of a pilot…

Information Theory · Computer Science 2025-12-23 Mert Ozates , Mohammad Kazemi , Gianluigi Liva , Deniz Gündüz

Unsourced random-access (U-RA) is a type of grant-free random access with a virtually unlimited number of users, of which only a certain number $K_a$ are active on the same time slot. Users employ exactly the same codebook, and the task of…

Information Theory · Computer Science 2021-12-10 Alexander Fengler , Peter Jung , Giuseppe Caire

We study the problem of unsourced random access (URA) over Rayleigh block-fading channels with a receiver equipped with multiple antennas. We propose a slotted structure with multiple stages of orthogonal pilots, each of which is randomly…

Information Theory · Computer Science 2023-07-17 Mohammad Javad Ahmadi , Mohammad Kazemi , Tolga M. Duman