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Related papers: Unsourced Multiple Access With Random User Activit…

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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 work we treat the unsourced random access problem on a Rayleigh block-fading AWGN channel with multiple receive antennas. Specifically, we consider the slowly fading scenario where the coherence block-length is large compared to the…

Information Theory · Computer Science 2021-09-22 Alexander Fengler , Osman Musa , Peter Jung , Giuseppe Caire

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…

Information Theory · Computer Science 2025-11-17 Mert Ozates , Mohammad Javad Ahmadi , Mohammad Kazemi , Deniz Gündüz , Tolga M. Duman

We investigate the unsourced random access scheme assuming that the base station is equipped with multiple antennas, and propose a high-performing solution utilizing on-off-division multiple access. We assume that each user spreads its…

Information Theory · Computer Science 2024-06-11 Mert Ozates , Mohammad Kazemi , Tolga M. Duman

Random access is a multiple access communication protocol where the users simultaneously communicate with a base station (BS) in an uncoordinated fashion. In this work, we consider the problem of multiuser detection in a random access…

Information Theory · Computer Science 2016-07-15 Md Mashud Hyder

An asynchronous $\ka$-active-user unsourced multiple access channel (AUMAC) is a key model for uncoordinated massive access in future networks. We focus on a scenario where each transmission is subject to the maximal delay constraint…

Information Theory · Computer Science 2025-01-28 Jyun-Sian Wu , Pin-Hsun Lin , Marcel A. Mross , Eduard A. Jorswieck

This article considers the massive MIMO unsourced random access problem on a quasi-static Rayleigh fading channel. Given a fixed message length and a prescribed number of channel uses, the objective is to construct a coding scheme that…

Information Theory · Computer Science 2022-03-09 Michail Gkagkos , Krishna R. Narayanan , Jean-Francois Chamberland , Costas N. Georghiades

In this paper, we study the problem of user activity detection and large-scale fading coefficient estimation in a random access wireless uplink with a massive MIMO base station with a large number $M$ of antennas and a large number of…

Information Theory · Computer Science 2021-09-22 Alexander Fengler , Saeid Haghighatshoar , Peter Jung , Giuseppe Caire

We consider an extension of the massive unsourced random access originally proposed by Polyanskiy to the case where the receiver has a very large number of antennas (a massive MIMO base station) and no channel state information is given to…

Information Theory · Computer Science 2019-01-04 Alexander Fengler , Giuseppe Caire , Peter Jung , Saeid Haghighatshoar

We derive an achievability bound to quantify the performance of a type-based unsourced multiple access system -- an information-theoretic model for grant-free multiple access with correlated messages. The bound extends available…

Information Theory · Computer Science 2025-04-29 Deekshith Pathayappilly Krishnan , Kaan Okumus , Khac-Hoang Ngo , Giuseppe Durisi

The number of wireless devices is drastically increasing, resulting in many devices contending for radio resources. In this work, we present an algorithm to detect active devices for unsourced random access, i.e., the devices are…

Information Theory · Computer Science 2023-01-13 Gilles Callebaut , François Rottenberg , Liesbet Van der Perre , Erik G. Larsson

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

Information Theory · Computer Science 2022-05-20 Mohammad Javad Ahmadi , Tolga M. Duman

This article introduces a novel paradigm for the unsourced multiple-access communication problem. This divide-and-conquer approach leverages recent advances in compressive sensing and forward error correction to produce a computationally…

Information Theory · Computer Science 2018-06-04 Vamsi K. Amalladinne , Avinash Vem , Dileep Kumar Soma , Krishna R. Narayanan , Jean-Francois Chamberland

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

This work considers an asynchronous $\textsf{K}_\text{a}$-active-user unsourced multiple access channel (AUMAC) with the worst-case asynchronicity. The transmitted messages must be decoded within $n$ channel uses, while some codewords are…

Information Theory · Computer Science 2024-01-31 Jyun-Sian Wu , Pin-Hsun Lin , Marcel A. Mross , Eduard A. Jorswieck

The network communication scenario where one or more receivers request all the information transmitted by different sources is considered. We introduce distributed polynomial-time network codes in the presence of malicious nodes. Our codes…

Networking and Internet Architecture · Computer Science 2010-01-18 Hongyi Yao , Theodoros K. Dikaliotis , Sidharth Jaggi , Tracey Ho

Polyanskiy proposed a framework for the unsourced multiple access channel (MAC) problem where users employ a common codebook in the finite blocklength regime. However, existing approaches handle channel noise before the joint decoder. In…

Information Theory · Computer Science 2026-04-14 Yuming Han , Yuxin Long

This paper considers an unsourced random access (URA) set-up equipped with a passive reconfigurable intelligent surface (RIS), where a massive number of unidentified users (only a small fraction of them being active at any given time) are…

Information Theory · Computer Science 2024-08-27 Mohammad Javad Ahmadi , Mohammad Kazemi , Tolga M. Duman

In this paper, we investigate an unsourced random access scheme for massive machine-type communications (mMTC) in the sixth-generation (6G) wireless networks with sporadic data traffic. Firstly, we establish a general framework for massive…

Information Theory · Computer Science 2022-03-01 Feiyan Tian , Xiaoming Chen , Lei Liu , Derrick Wing Kwan Ng

Recently, non-orthogonal codes have been advocated for IoT massive access. Activity detection has been demonstrated to entail common support recovery in a jointly sparse multiple measurement vector (MMV) problem and MMV algorithms have been…

Signal Processing · Electrical Eng. & Systems 2019-08-06 Mohammad Naseri Tehrani , Shahrokh Farahmand