RIS-aided unsourced random access
File(s)
Author(s)
Ahmadi, Mohammad Javad
Kazemi, Mohammad
Duman, Tolga M
Type
Conference Paper
Abstract
This paper considers an unsourced random access (URA) setup equipped with a passive reconfigurable intelligent surface (RIS), where a massive number of unidentified users (of which only a small fraction are active at a given time) share the same communication resources. We propose a slotted transmission scheme that operates in two phases. In the first phase, called the RIS configuration phase, the base station (BS) detects the active pilots and estimates their respective channel state information (CSI). Then, using the estimated CSI, the BS suitably selects the phase shifts of the RIS elements. In the second phase, called the data phase, transmitted messages of active users are decoded. The proposed channel estimator offers the capability to estimate the channel coefficients of the users whose pilots interfere with each other without prior access to the list of selected pilots or the number of active users. In this paper, we consider the direct link between the users and the BS to be completely blocked, and show that employing RIS improves the performance of the URA system by creating additional links between the BS and the users. The effectiveness of the proposed algorithms is confirmed through computer simulations.
Date Issued
2024-02-26
Date Acceptance
2023-12-01
Citation
GLOBECOM 2023 - 2023 IEEE Global Communications Conference, 2024, pp.3270-3275
ISSN
2334-0983
Publisher
IEEE
Start Page
3270
End Page
3275
Journal / Book Title
GLOBECOM 2023 - 2023 IEEE Global Communications Conference
Copyright Statement
Copyright © 2023 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Source
IEEE Conference on Global Communications (IEEE GLOBECOM) - Intelligent Communications for Shared Prosperity
Subjects
CHANNEL ESTIMATION
Engineering
Engineering, Electrical & Electronic
INTELLIGENT REFLECTING SURFACE
Science & Technology
Technology
Telecommunications
WIRELESS NETWORK
Publication Status
Published
Start Date
2023-12-04
Finish Date
2023-12-08
Coverage Spatial
MALAYSIA, Kuala Lumpur