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Massive MIMO for Dependable Communication

Willhammar, Sara LU (2022)
Abstract
Cellular communication is constantly evolving; currently 5G systems are being deployed and research towards 6G is ongoing. Three use cases have been discussed as enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC). To fulfill the requirements of these use cases, new technologies are needed and one enabler is massive multiple-input multiple-output (MIMO). By increasing the number of antennas at the base station side, data rates can be increased, more users can be served simultaneously, and there is a potential to improve reliability. In addition, it is possible to achieve better coverage, improved energy efficiency, and low-complex user devices. The performance of... (More)
Cellular communication is constantly evolving; currently 5G systems are being deployed and research towards 6G is ongoing. Three use cases have been discussed as enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC). To fulfill the requirements of these use cases, new technologies are needed and one enabler is massive multiple-input multiple-output (MIMO). By increasing the number of antennas at the base station side, data rates can be increased, more users can be served simultaneously, and there is a potential to improve reliability. In addition, it is possible to achieve better coverage, improved energy efficiency, and low-complex user devices. The performance of any wireless system is limited by the underlying channels. Massive MIMO channels have shown several beneficial properties: the array gain stemming from the combining of the signals from the many antennas, improved user separation due to favourable propagation -- where the user channels become pair-wise orthogonal -- and the channel hardening effect, where the variations of channel gain decreases as the number of antennas increases. Previous theoretical works have commonly assumed independent and identically distributed (i.i.d.) complex Gaussian channels. However, in the first studies on massive MIMO channels, it was shown that common outdoor and indoor environments are not that rich in scattering, but that the channels are rather spatially correlated. To enable the above use cases, investigations are needed for the targeted environments. This thesis focuses on the benefits of deploying massive MIMO systems to achieve dependable communication in a number of scenarios related to the use cases. The first main area is the study of an industrial environment and aims at characterizing and modeling massive MIMO channels to assess the possibility of achieving the requirements of URLLC in a factory context. For example, a unique fully distributed array is deployed with the aim to further exploit spatial diversity. The other main area concerns massive MIMO at sub-GHz, a previously unexplored area. The channel characteristics when deploying a physically very large array for IoT networks are explored. To conclude, massive MIMO can indeed bring great advantages when trying to achieve dependable communication. Although channels in regular indoor environments are not i.i.d. complex Gaussian, the model can be justified in rich scattering industrial environments. Due to massive MIMO, the small-scale fading effects are reduced and when deploying a distributed array also the large-scale fading effects are reduced. In the Internet-of-Things (IoT) scenario, the channel is not as rich scattering. In this use case one can benefit from the array gain to extend coverage and improved energy efficiency, and diversity is gained due to the physically large array. (Less)
Abstract (Swedish)
Cellulär kommunikation utvecklas ständigt; för närvarande installeras 5G-system och forskning kring 6G pågår. Tre användningsfall som diskuteras är enhanced mobile broadband (eMBB), massive machine-type communication (mMTC) och ultra-reliable low-latency communication (URLLC). För att uppfylla kraven i dessa användningsfall behövs ny teknik och en kandidat är massive multiple-input multiple-output (MIMO). Genom att öka antalet antenner på basstationens sida kan datahastigheterna ökas, fler användare kan betjänas samtidigt och det finns en potential att förbättra tillförlitligheten. Dessutom är det möjligt att uppnå bättre täckning, förbättrad energieffektivitet och lågkomplexa användarenheter. Prestandan för alla trådlösa system begränsas... (More)
Cellulär kommunikation utvecklas ständigt; för närvarande installeras 5G-system och forskning kring 6G pågår. Tre användningsfall som diskuteras är enhanced mobile broadband (eMBB), massive machine-type communication (mMTC) och ultra-reliable low-latency communication (URLLC). För att uppfylla kraven i dessa användningsfall behövs ny teknik och en kandidat är massive multiple-input multiple-output (MIMO). Genom att öka antalet antenner på basstationens sida kan datahastigheterna ökas, fler användare kan betjänas samtidigt och det finns en potential att förbättra tillförlitligheten. Dessutom är det möjligt att uppnå bättre täckning, förbättrad energieffektivitet och lågkomplexa användarenheter. Prestandan för alla trådlösa system begränsas av de underliggande kanalerna. Massive MIMO-kanaler har visat flera fördelaktiga egenskaper: arrayförstärkning som kommer från kombinationen av signalerna från de många antennerna, förbättrad användarseparation på grund av gynnsam vågutbredning -- där användarkanalerna blir parvis ortogonala -- och kanalhärdningseffekten, där variationerna av kanalstyrkan minskar när antalet antenner ökar. Tidigare teoretiska arbeten har vanligtvis antagit oberoende och identiskt distribuerade komplexa Gaussiska kanaler. I de första studierna på massive MIMO-kanaler visades det dock att vanliga utomhus- och inomhusmiljöer inte är så rika på spridare, utan att kanalerna är rumsligt korrelerade. För att möjliggöra ovanstående användningsfall behövs undersökningar i relevanta miljöer. Denna avhandling fokuserar på fördelarna med massive MIMO-system för att uppnå pålitlig kommunikation i ett antal scenarier relaterade till användningsfallen. Det första huvudområdet är en studie av en industriell miljö som syftar till att karakterisera och modellera massive MIMO-kanaler för att bedöma möjligheten att uppnå kraven för URLLC i en fabrikskontext. Till exempel används en unik fullt utspridd array i syfte att ytterligare utnyttja rumslig diversitet. Det andra huvudområdet gäller massive MIMO vid sub-GHz-frekvenser, ett tidigare outforskat område. Kanalegenskaperna när en använder en fysiskt mycket stor array för IoT-nätverk utforskas. Sammanfattningsvis kan massive MIMO ge stora fördelar när en försöker uppnå pålitlig kommunikation. Även om kanaler i vanliga inomhusmiljöer inte är oberoende och identiskt distribuerade komplexa Gaussiska kanaler, så kan modellen motiveras i industriella miljöer med rik spridning. Tack vare massive MIMO reduceras de småskaliga fädningseffekterna, och med en utspridd array reduceras även de storskaliga fädningseffekterna. I scenariot Internet-of-Things (IoT) är kanalen inte lika rik på spridning. I detta användningsfall kan en dra nytta av arrayförstärkningen för att utöka täckningen och förbättra energieffektiviteten, samt diversitet fås på grund av den fysiskt stora arrayen. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Prof. Linnartz, Jean-Paul, Signify and Eindhoven University of Technology, The Netherlands.
organization
alternative title
Massive MIMO för tillförlitlig kommunikation
publishing date
type
Thesis
publication status
published
subject
keywords
Channel characterisation, Channel measurements, Channel modeling, Industrial automation, Industry 4.0, Internet-of-Things, Massive MIMO, mMTC, Reliability, URLLC
issue
151
pages
222 pages
publisher
Faculty of Engineering, Lund University
defense location
Lecture Hall E:1406, building E, Ole Römers väg 3, Faculty of Engineering LTH, Lund University, Lund. The dissertation is to be live streamed, but part of the premises will be excluded from the live stream.
defense date
2022-12-09 09:15:00
ISSN
1654-790X
ISBN
978-91-8039-460-4
978-91-8039-459-8
project
Massive MIMO for dependable communication
5G for Smart Manufacturing
Massive MIMO for reliable remote monitoring
language
English
LU publication?
yes
id
ef04caa0-b33d-4acf-b95b-408e0760033c
date added to LUP
2022-11-14 16:05:49
date last changed
2023-06-29 08:57:38
@phdthesis{ef04caa0-b33d-4acf-b95b-408e0760033c,
  abstract     = {{Cellular communication is constantly evolving; currently 5G systems are being deployed and research towards 6G is ongoing. Three use cases have been discussed as enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC). To fulfill the requirements of these use cases, new technologies are needed and one enabler is massive multiple-input multiple-output (MIMO). By increasing the number of antennas at the base station side, data rates can be increased, more users can be served simultaneously, and there is a potential to improve reliability. In addition, it is possible to achieve better coverage, improved energy efficiency, and low-complex user devices. The performance of any wireless system is limited by the underlying channels. Massive MIMO channels have shown several beneficial properties: the array gain stemming from the combining of the signals from the many antennas, improved user separation due to favourable propagation -- where the user channels become pair-wise orthogonal -- and the channel hardening effect, where the variations of channel gain decreases as the number of antennas increases. Previous theoretical works have commonly assumed independent and identically distributed (i.i.d.) complex Gaussian channels. However, in the first studies on massive MIMO channels, it was shown that common outdoor and indoor environments are not that rich in scattering, but that the channels are rather spatially correlated. To enable the above use cases, investigations are needed for the targeted environments. This thesis focuses on the benefits of deploying massive MIMO systems to achieve dependable communication in a number of scenarios related to the use cases. The first main area is the study of an industrial environment and aims at characterizing and modeling massive MIMO channels to assess the possibility of achieving the requirements of URLLC in a factory context. For example, a unique fully distributed array is deployed with the aim to further exploit spatial diversity. The other main area concerns massive MIMO at sub-GHz, a previously unexplored area. The channel characteristics when deploying a physically very large array for IoT networks are explored. To conclude, massive MIMO can indeed bring great advantages when trying to achieve dependable communication. Although channels in regular indoor environments are not i.i.d. complex Gaussian, the model can be justified in rich scattering industrial environments. Due to massive MIMO, the small-scale fading effects are reduced and when deploying a distributed array also the large-scale fading effects are reduced. In the Internet-of-Things (IoT) scenario, the channel is not as rich scattering. In this use case one can benefit from the array gain to extend coverage and improved energy efficiency, and diversity is gained due to the physically large array.}},
  author       = {{Willhammar, Sara}},
  isbn         = {{978-91-8039-460-4}},
  issn         = {{1654-790X}},
  keywords     = {{Channel characterisation; Channel measurements; Channel modeling; Industrial automation; Industry 4.0; Internet-of-Things; Massive MIMO; mMTC; Reliability; URLLC}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{151}},
  publisher    = {{Faculty of Engineering, Lund University}},
  school       = {{Lund University}},
  title        = {{Massive MIMO for Dependable Communication}},
  url          = {{https://lup.lub.lu.se/search/files/128512014/thesis_sara_willhammar.pdf}},
  year         = {{2022}},
}