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Related papers: SPARCs for Unsourced Random Access

200 papers

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

Massive communication is one of key scenarios of 6G where two magnitude higher connection density would be required to serve diverse services. As a promising direction, unsourced multiple access has been proved to outperform significantly…

Information Theory · Computer Science 2024-11-18 Yifei Yuan , Yuhong Huang , Chunlin Yan , Sen Wang , Shuai Ma , Xiaodong Shen

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

A random access code (RAC) is a communication task in which the sender encodes a random message into a shorter one to be decoded by the receiver so that a randomly chosen character of the original message is recovered with some probability.…

Quantum Physics · Physics 2023-10-23 Gabriel Pereira Alves , Nicolas Gigena , Jędrzej Kaniewski

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

This paper studies a generalization of sparse superposition codes (SPARCs) for communication over the complex additive white Gaussian noise (AWGN) channel. In a SPARC, the codebook is defined in terms of a design matrix, and each codeword…

Information Theory · Computer Science 2021-06-25 Kuan Hsieh , Ramji Venkataramanan

Sparse Code Multiple Access (SCMA) is an enabling code-domain non-orthogonal multiple access (NOMA)scheme for massive connectivity and ultra low-latency in future machine-type communication networks. As an evolved variant of code division…

Information Theory · Computer Science 2021-05-17 Saumya Chaturvedi , Zilong Liu , Vivek Ashok Bohara , Anand Srivastava , Pei Xiao

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 2021-08-11 Alexander Fengler , Peter Jung , Giuseppe Caire

In this paper, we explore an efficient uncoupled unsourced random access (UURA) scheme for 6G massive communication. UURA is a typical framework of unsourced random access that addresses the problems of codeword detection and message…

Information Theory · Computer Science 2024-05-07 Feiyan Tian , Xiaoming Chen , Chongwen Huang , Zhaoyang Zhang

Sparse regression codes (SPARCs) are a class of codes that encode information through the superposition of columns of a randomised coding matrix. The combination with an outer non-binary low density parity check (NB-LDPC) code was recently…

Information Theory · Computer Science 2025-09-23 Alexander Fengler , Burak Çakmak , Giuseppe Caire

In this paper, a sparse Kronecker-product (SKP) coding scheme is proposed for unsourced multiple access. Specifically, the data of each active user is encoded as the Kronecker product of two component codewords with one being sparse and the…

Information Theory · Computer Science 2021-06-04 Zeyu Han , Xiaojun Yuan , Chongbin Xu , Shuchao Jiang , Xin Wang

We study sparse regression codes (SPARC) for multiple access channels with multiple receive antennas, in non-coherent flat fading channels. We propose a novel practical decoder, referred to as maximum likelihood matching pursuit (MLMP),…

Signal Processing · Electrical Eng. & Systems 2025-07-16 V S V Sandeep , Sai Dinesh Kancharana , Arun Pachai Kannu

This work considers the problem of integrated sensing and communications (ISAC) with a massive number of unsourced and uncoordinated users. In the proposed model, known as the unsourced ISAC system (UNISAC), all active communication and…

Information Theory · Computer Science 2026-04-21 Mohammad Javad Ahmadi , Rafael F. Schaefer , H. Vincent Poor

In this paper, we propose a new polar coding scheme for the unsourced, uncoordinated Gaussian random access channel. Our scheme is based on sparse spreading, treat interference as noise and successive interference cancellation (SIC). On the…

Information Theory · Computer Science 2020-07-14 Mengfan Zheng , Yongpeng Wu , Wenjun Zhang

We discuss the problem of designing channel access architectures for enabling fast, low-latency, grant-free and uncoordinated uplink for densely packed wireless nodes. Specifically, we study random-access codes, previously introduced for…

Information Theory · Computer Science 2019-07-23 Suhas S Kowshik , Kirill Andreev , Alexey Frolov , Yury Polyanskiy

In this paper, we discuss the potential for improvement of the simple random access scheme by utilizing local information such as the received signal-to-interference-plus-noise-ratio (SINR). We propose a spatially adaptive random access…

Information Theory · Computer Science 2015-05-05 Dong Min Kim , Seong-Lyun Kim

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 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

Massive random access of devices in the emerging Open Radio Access Network (O-RAN) brings great challenge to the access control and management. Exploiting the bursting nature of the access requests, sparse active user detection (SAUD) is an…

Machine Learning · Computer Science 2023-03-07 Xiao Tang , Sicong Liu , Xiaojiang Du , Mohsen Guizani

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