IRS-Assisted Rayleigh Fading MISO Systems : beamforming and asymptotic Analysis
department or school: Applied Science, Faculty of
department or school: Engineering, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Alnahhas, Bayan
issued: 2020-05-25T17:18:39Z
issued: 2020
related degree: Master of Applied Science - MASc
degree grantor: University of British Columbia
description: The recent concept of intelligent reflecting surfaces (IRS) enabled wireless communication can overcome the adverse effects of the wireless channel by manipulating the propagation of the radio waves in the environment. This emerging technology, which relies on low-cost passive reflecting elements, is shown to yield promising performance results in recent studies that often focus on Rayleigh fading environments and assume the availability of perfect channel state information (CSI) at the base station (BS) and the IRS. This work considers the practical setting where only imperfect CSI is available at the BS and the IRS, and studies the downlink sum-rate performance of a multi-user IRS-assisted multiple-input single-output (MISO) system in the asymptotic regime where the number of BS antennas, IRS elements and users grow large. We first derive the MMSE estimates of the IRS-assisted and direct channels under a protocol that ensures that the IRS element stay passive. Then we formulate the signal-to-interference-plus-noise ratio (SINR) and sum rate expressions under maximum ratio transmission (MRT) precoding, and obtain their asymptotically tight deterministic approximations using tools from random matrix theory. The asymptotic performance limits are also derived that reveal that in Rayleigh fading environments, IRS only yields an array gain and loses on the reflect beamforming gain promised by existing works. Simulation results show the tightness of the asymptotic expressions for moderate system dimensions and reveal important insights into how beneficial the IRSs are when the environment has rich scattering as represented in Rayleigh fading. It turns out that IRS introduces high sum- rate gains in noise-limited scenarios whereas the gains start to diminish in interference-limited scenarios.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/74571
note: IRS-ASSISTED RAYLEIGH FADING MISO SYSTEMS: BEAMFORMING ANDASYMPTOTIC ANALYSISbyBayan AlnahhasB.Sc. Hons., Effat University, 2018A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFMASTER OF APPLIED SCIENCEinThe College of Graduate Studies(Electrical Engineering)THE UNIVERSITY OF BRITISH COLUMBIA(Okanagan)March 2020© Bayan Alnahhas, 2020The following individuals certify that they have read, and recommend to the College of GraduateStudies for acceptance, a thesis/dissertation entitled:IRS-ASSISTED RAYLEIGH FADING MISO SYSTEMS:BEAMFORMING AND ASYMPTOTIC ANALYSISsubmitted by Bayan Alnahhas in partial fulfilment of the requirements of the degree ofMaster of Applied ScienceProf. Anas Chaaban, School of EngineeringSupervisorProf. Md. Jahangir Hossain, School of EngineeringSupervisory Committee MemberProf. Chen Feng, School of EngineeringSupervisory Committee MemberProf. Mahmudur Fatmi, School of EngineeringUniversity ExamineriiAbstractThe recent concept of intelligent reflecting surfaces (IRS) enabled wireless communication canovercome the adverse effects of the wireless channel by manipulating the propagation of the radiowaves in the environment. This emerging technology, which relies on low-cost passive reflectingelements, is shown to yield promising performance results in recent studies that often focus onRayleigh fading environments and assume the availability of perfect channel state information(CSI) at the base station (BS) and the IRS. This work considers the practical setting where onlyimperfect CSI is available at the BS and the IRS, and studies the downlink sum-rate performanceof a multi-user IRS-assisted multiple-input single-output (MISO) system in the asymptotic regimewhere the number of BS antennas, IRS elements and users grow large. We first derive theMMSE estimates of the IRS-assisted and direct channels under a protocol that ensures that theIRS element stay passive. Then we formulate the signal-to-interference-plus-noise ratio (S…
has type: Thesis/Dissertation
date issued: 2020-09
is shown at: 10.14288/1.0391010
language: eng
degree discipline: Electrical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/74571