In the upcoming era of communication systems, there is an anticipated shift towards using lower-grade hardware components to optimize size, cost, and power consumption. This shift is particularly beneficial for multiple-input multiple-output (MIMO) systems and internet-of-things devices, which require numerous components and extended battery lifes. However, using lower-grade components introduces impairments, including various non-linear and time-varying distortions affecting communication signals. Traditionally, these distortions have been treated as additional noise due to the lack of a rigorous theory. This thesis explores new perspective on how distortion structure can be exploited to optimize communication performance. We investigate the problem of distortion-aware beamforming in various scenarios.  In the first part of this thesis, we focus on systems with limited fronthaul capacity. We propose an optimized linear precoding for advanced antenna systems (AAS) operating at a 5G base station (BS) within the constraints of a limited fronthaul capacity, modeled by a quantizer. The proposed novel precoding minimizes the mean-squared error (MSE) at the receiver side using a sphere decoding (SD) approach.  After analyzing MSE minimization, a new linear precoding design is proposed to maximize the sum rate of the same system in the second part of this thesis. The latter problem is solved by a novel iterative algorithm inspired by the classical weighted minimum mean square error (WMMSE) approach. Additionally, a heuristic quantization-aware precoding method with lower computational complexity is presented, showing that it outperforms the quantization-unaware baseline. This baseline is an optimized infinite-resolution precoding which is then quantized. This study reveals that it is possible to double the sum rate at high SNR by selecting weights and precoding matrices that are quantization-aware.  In the third part and final part of this thesis, we focus on the signaling problem in mobile millimeter-wave (mmWave) communication. The challenge of mmWave systems is the rapid fading variations and extensive pilot signaling. We explore the frequency of updating the combining matrix in a wideband mmWave point-to-point MIMO under user equipment (UE) mobility. The concept of beam coherence time is introduced to quantify the frequency at which the UE must update its downlink receive combining matrix. The study demonstrates that the beam coherence time can be even hundreds of times larger than the channel coherence time of small-scale fading. Simulations validate that the proposed lower bound on this defined concept guarantees no more than 50 \% loss of received signal gain (SG). / I den kommande eran av kommunikationssystem finns det en förväntad förändringmot att använda hårdvarukomponenter av lägre kvalitet för att optimera storlek, kostnad och strömförbrukning. Denna förändring är särskilt fördelaktig för MIMO-system(multiple-input multiple-output) och internet-of-things-enheter, som kräver många komponenter och förlängd batteritid. Användning av komponenter av lägre kvalitet medfördock försämringar, inklusive olika icke-linjära och tidsvarierande förvrängningar sompåverkar kommunikationssignaler. Traditionellt har dessa förvrängningar behandlatssom extra brus på grund av avsaknaden av en rigorös teori. Denna avhandling utforskarett nytt perspektiv på hur distorsionsstruktur kan utnyttjas för att optimera kommunikationsprestanda. Vi undersöker problemet med distorsionsmedveten strålformning iolika scenarier. I den första delen av detta examensarbete fokuserar vi på system med begränsadfronthaulkapacitet. Vi föreslår en optimerad linjär förkodning för avancerade antennsystem (AAS) som arbetar vid en 5G-basstation (BS) inom begränsningarna av en begränsad fronthaulkapacitet, modellerad av en kvantiserare. Den föreslagna nya förkodningen minimerar medelkvadratfelet (MSE) på mottagarsidan med användning av ensfäravkodningsmetod (SD). Efter att ha analyserat MSE-minimering, föreslås en ny linjär förkodningsdesignför att maximera summahastigheten för samma system i den andra delen av dennaavhandling. Det senare problemet löses av en ny iterativ algoritm inspirerad av denklassiska vägda minsta medelkvadratfel (WMMSE)-metoden. Dessutom presenterasen heuristisk kvantiseringsmedveten förkodningsmetod med lägre beräkningskomplexitet, som visar att den överträffar den kvantiseringsomedvetna baslinjen. Denna baslinje är en optimerad förkodning med oändlig upplösning som sedan kvantiseras. Dennastudie avslöjar att det är möjligt att fördubbla summahastigheten vid hög SNR genomatt välja vikter och förkodningsmatriser som är kvantiseringsmedvetna. I den tredje delen och sista delen av denna avhandling fokuserar vi på signaleringsproblemet i mobil millimetervågskommunikation (mmWave). Utmaningen medmmWave-system är de snabba blekningsvariationerna och omfattande pilotsignalering.Vi utforskar frekvensen av att uppdatera den kombinerande matrisen i en bredbandsmmWave punkt-till-punkt MIMO under användarutrustning (UE) mobilitet. Konceptet med strålkoherenstid introduceras för att kvantifiera frekvensen vid vilken UE:nmåste uppdatera sin nedlänksmottagningskombinationsmatris. Studien visar att strålkoherenstiden kan vara till och med hundratals gånger större än kanalkoherenstiden försmåskalig fädning. Simuleringar bekräftar att den föreslagna nedre gränsen för dettadefinierade koncept inte garanterar mer än 50 % förlust av mottagen signalförstärkning(SG) / <p>QC 20240219</p>

With the tremendous growth in the mobile data traffic, the demand for highdata rate is increasing rapidly, and higher frequency resources shall be exploredto alleviate the congestion in the overcrowded spectrum, thus, the millimeterwave (mmWave) frequency resource ranging from 30 GHz to 300 GHz has beenrecognized as a nature fit for the fifth-generation (5G) and beyond network. Tocompensate the severe path-loss in the mmWave band as well to realize theefficient transmissions by applying the low-cost architecture, it is of intereststo investigate the beamforming schemes with large-scale antenna arrays andthe full-duplex (FD) relaying strategy, which are indispensable in the operationof directional signal transmission and the efficient spectrum utilization inthe mmWave transmission, respectively. However, the self-interference (SI)occurring between the separate antenna arrays is the main impediment inrealizing a FD wireless node while considering the simultaneous transmission andreception.This thesis project aims to design efficient hybrid beamforming algorithms toimprove spectral efficiency and eliminate SI. The orthogonal matching pursuit(OMP)-based hybrid analog-digital beamforming design, and the alternatingdirection method of multipliers (ADMM)-based schemes are explored to improvethe spectral efficiency and eliminate the SI in this work. Moreover, a fast ADMMenabledhybrid precoding approach with SI cancellation is proposed to achievethe efficient performance and superior convergence compared with the existingschemes, as it is verified by the presented numerical simulations. / Med den enorma tillväxten i den mobila datatrafiken ökar efterfrågan påhög datahastighet snabbt, och högre frekvensresurser ska undersökas för attminska trängseln i det överbefolkade spektrumet, vilket innebär att Volymvågens(mmwave) frekvensresurs, som sträcker sig från 30 GHz till 300 GHz, har erkäntssom en naturlig resurs för den femte generationen (5G) och utanför nätverket.För att kompensera den allvarliga förlusten av tågläge i mmwave-bandet ochför att förverkliga de effektiva sändningarna genom att tillämpa den billigaarkitekturen.Det är av intresse att undersöka strålformningsprogrammen medstorskaliga antennmatriser och strategin för återutläggning av hela duplex (FD),som är oumbärliga för att driva den direkta signal överföringen och det effektivaspektrumutnyttjandet i mmwave-transmissionen.separata antennmatriser är etthuvudhinder för att förverkliga en trådlös nod från FD samtidigt som manöverväger samtidig överföring och mottagning.Syftet med detta avhandlingsprojekt är att utforma effektiva kombineradestrålformningsinformationsalgoritmer för att förbättra spektraleffektiviteten ocheliminera SI. Den ortogonala matchande jakten (OMP)-baserad hybrid analogdigitalstrålformning, och metoden med alternerande riktning för multiplikatorer(ADMM)-baserade system utforskas för att förbättra spektraleffektiviteten ochelimineraSI i det här arbetet. Dessutom föreslås en snabb, adMM-aktiveradhybrid förkonditionering med SI-annullering för att uppnå effektiv prestandaoch överlägset konvergens jämfört med de befintliga systemen, eftersom denkontrolleras av de presenterade numeriska simuleringarna.

The paper details the usage of mmWave radars to track people and monitor their movement through predefined zones of interest. The theoretical part describes the physical nature of the technology and then describes algorithms which can be used to monitor using it to monitor the movement of people. In the practical part, I have developed a concrete algorithm which can be used to monitor customer queues and cash registers in shops and inform the cashiers when their presence is needed, as well as gather impersonal GDPR-compliant data about the customer's habits. Afterwards, I have developed a visualization for the Windows platform, which can be used to communicate with the radar, manage its configuration, visualize the events in real time and perform further analysis of the measured data.

Millimeter-wave (mmWave) is widely investigated for indoor communication scenarios thanks to the available rich spectrum. However, the shortened antenna size and the high frequency make mmWave extra sensitive to blockages. Indoor dense space (IDS) is a specific type of indoor environment, where the compact geometry together with a high number of blocking objects and users make it hard to fulfill the data rate required by all of the users in the mmWave network. With the capability of redirecting signals, the reconfigurable intelligent surface (RIS) has the potential to overcome the attenuation brought by the blockage. Aside from the promising improvement in data rate brought by the RIS, the power supply for RIS is also a major concern in IDS due to the cabling and the batteries. Dynamic RIS has the capability of reconfiguring its phase-shifts to offer a higher gain in data rate with the price of consuming power. In comparison, by sacrificing the reconfigurability, static RIS does not require any power, cabling, or batteries but is expected to provide lower data rates. To find the balance between the performance and cost trade-off, the concept of self-sustainable RIS in IDS is proposed. This approach involves the utilization of specific RIS elements to harvest energy, thereby providing support for the power requirements of the RIS operation, consequently reducing the reliance on traditional cabling infrastructure. In this work, we compare the coverage extension effect brought by deploying static, dynamic, and self-sustainable RISs in the aircraft cabin which is a typical example of an IDS. To capture the propagation characteristics of a RIS in IDS, we first provide guidelines for modeling the RIS in the ray tracing (RT) simulator, and then we select the best locations to deploy RISs among three candidates. For each type of RIS deployment, we propose an optimization algorithm, which jointly configures the RIS phase-shifts and the time resources to provide the maximum equal achievable data rate for all of the users. Additionally, for the self-sustainable RIS, the working mode of each RIS element is also jointly configured such that each element is used either to reflect the incoming signal or to use the signal for energy harvesting. Based on the results, the signal propagation of a single base station (BS) can be extended from 3 rows to 11 rows by deploying static or dynamic RISs. The minimal achievable data rate is 35.4 Mbps with the static RISs and 45.3 Mbps with the dynamic RISs. The results indicate that due to the limitation of self-sustainable constraints, RISs with 16 elements are hard to cover the whole 11 rows in the considered cabin. Nevertheless, with self-sustainable RIS, 10 more UEs are covered compared to the case where no RIS is deployed. The minimal data rate with the help of the self-sustainable RISs within the coverage is 0.75 Mbps. The feasibility study shows that this energy requirement has a greater likelihood of being fulfilled as the number of elements in RIS increases. / Millimetervåg (mmWave) är allmänt undersökt för inomhuskommunikationsscenarier tack vare det tillgängliga rika spektrumet. Den förkortade antennstorleken och den höga frekvensen gör dock mmWave extra känslig för blockeringar. Indoor dense space (IDS) är en specifik typ av inomhusmiljö, där den kompakta geometrin tillsammans med ett stort antal blockerande objekt och användare gör det svårt att uppfylla den datahastighet som krävs av alla användare i mmWave-nätverket. Med förmågan att omdirigera signaler har reconfigurable intelligent surface (RIS) potentialen att övervinna dämpningen av blockeringen. Bortsett från den lovande förbättringen av datahastigheten som RIS ger, är strömförsörjningen för RIS också ett stort problem inom IDS på grund av kablarna och batterierna. Dynamic RIS har förmågan att omkonfigurera sina fasförskjutningar för att erbjuda en högre förstärkning i datahastighet med priset för att förbruka energi. I jämförelse, genom att offra omkonfigurerbarheten, kräver statisk RIS ingen ström, kablar eller batterier utan förväntas ge lägre datahastigheter. För att hitta balansen mellan prestanda och kostnadsavvägning föreslås konceptet med självförsörjande RIS i IDS. Detta tillvägagångssätt involverar användningen av specifika RIS-element för att skörda energi, vilket ger stöd för strömkraven för RIS-driften, vilket minskar beroendet av traditionell kabelinfrastruktur. I det här arbetet jämför vi den täckningsförlängningseffekt som uppstår genom att installera statiska, dynamiska och självförsörjande RIS i flygplanskabinen, vilket är ett typiskt exempel på en IDS. För att fånga utbredningsegenskaperna för en RIS i IDS ger vi först riktlinjer för modellering av RIS i ray tracing (RT)-simulatorn, och sedan väljer vi de bästa platserna för att distribuera RIS bland tre kandidater. För varje typ av RIS-distribution föreslår vi en optimeringsalgoritm, som gemensamt konfigurerar RIS-fasförskjutningarna och tidsresurserna för att tillhandahålla den maximalt lika möjliga datahastigheten för alla användare. Dessutom, för den självförsörjande RIS, är arbetsläget för varje RIS-element också gemensamt konfigurerat så att varje element används antingen för att reflektera den inkommande signalen eller för att använda signalen för energiskörd. Baserat på resultaten kan signalutbredningen av en enda base station (BS) utökas från 3 rader till 11 rader genom att distribuera statiska eller dynamiska RIS:er. Den minsta möjliga datahastigheten är 35,4 Mbps med statiska RIS och 45,3 Mbps med dynamiska RIS. Resultaten indikerar att på grund av begränsningen av självförsörjande begränsningar är RIS med 16 element svåra att täcka hela 11 rader i den övervägda kabinen. Ändå, med självförsörjande RIS, täcks 10 fler UE jämfört med fallet där ingen RIS är utplacerad. Den minimala datahastigheten med hjälp av de självförsörjande RIS:erna inom täckningen är 0,75 Mbps. Förstudien visar att detta energibehov har större sannolikhet att uppfyllas i takt med att antalet element i RIS ökar.

Dynamic Spectrum Access (DSA), also known as Dynamic Spectrum Management, is the method of utilizing a set of spectrum techniques in real time to provide the ability to share wireless channels between Primary (or licensed) users (PUs) and Secondary (or unlicensed) users (SUs). The system is so designed that under normal circumstances, the PUs always get priority, but DSA enables the SUs to use the licensed bands as long as they do not create any interference on the PUs. Hence, the goal of utilizing the spectrum more efficiently can be achieved. Though DSA has been researched extensively as a new concept, it is still under development and several challenges remain unsolved. DSA is recognized as a vital component in 5G-and-beyond network deployment scenarios. Although 5G networks can work in sub-6GHz bands, higher frequency bands (like 28 GHz and 60 GHz) are particularly of interest as they offer much larger bandwidth and regulatory agencies have been announcing licensing plans for these emerging bands. These higher frequency bands could enable extremely high-speed wireless communication by leveraging the gains of highly directional antennas. Smart devices used worldwide has already surpassed 22 billion and is only going to increase in the coming years. Channel allocation and high-speed communication will be the backbone to drive this enormous network of devices, and DSA and directional antenna communication mechanisms will be the key factors governing the future communication infrastructure. In this dissertation, we show how omnidirectional DSA techniques can be applied towards directional cases, i.e., replacing the omnidirectional antennas with directional antennas working in the millimeter wave (mmWave) bands. MmWave enables ultra-high speed transmission and reception, but with some caveats; these antennas should be deployed in line-of-sight (LOS) and a lot of transmission and reception properties depend on how the antennas are aligned, their steering angle, beamwidth and field-of-view (FOV). It is a challenge to take into consideration all of these factors and come up with a solution of ideal signal-to-interference-plus-noise-ratio (SINR) combination between a set of transmitters and receivers. This dissertation sets a guideline on how small cell mmWave transmitters and receivers can be deployed in a densely populated area by working in a coalition (such as by smartly allocating channels to coalitions with more users). Mobility and varying orientations of mmWave as part of dynamic coalitions present new challenges we undertake. Hence, an area where this research can be very apt is vehicular networks, leveraging the high-speed communication provided by mmWave networks. Since the nodes in this case, the vehicles, will be primarily in motion, our research can be applied especially, because we are investigating the antenna designs by considering their beamwidths, steering angles power budgeting.

The emergence of unmanned aerial vehicles (UAVs) along with the implementation of 5G networks offers exciting opportunities in expanding wireless capabilities. Not only is improved wireless performance expected with traditional devices such as mobile phones, but new use cases such as the internet-of-things and autonomous vehicle operation will rely on 5G and future network generations. In such widespread applications, from transportation to vital business operation, reliable and often guaranteed connectivity is required for safety and commercial approval. Introducing UAVs into network processes has been explored and implemented in certain instances to take advantage of the flexibility drone devices offer in their mobility and control to address these evolving network possibilities. While practical UAV deployment in certain network cases has been demonstrated, including coverage restoration in disaster relief scenarios, more ambitious goals of 5G will have additional considerations. This includes autonomous vehicles (AVs) whose operation is defined by levels representing varying degrees of autonomy. With computational requirements exponentially increasing as a vehicle's autonomy level is increased, 5G is expected to play an integral role in offloading certain vehicle tasks to the cloud. This thesis then proposes UAV based measurement opportunities as a method to characterize 5G coverage as part of autonomous vehicle processes to identify the proper level of autonomy that can operate safely given the current RF environment. This thesis proposes an UAV based measurement system that would provide coverage verification employing a platform capable of precise RF measurements and enhanced spatial sampling of the environment. Methods employed to traditionally characterize available coverage, including cellular drive tests, do not result in accurate enough measurements for AV use cases. Where lack of coverage in common network processes and use cases can result in dropped calls and poor connectivity in mobile devices, autonomous systems proposed in evolving network generations that deal with safety and mission critical functions must have guaranteed and verified coverage. Data produced in this thesis demonstrates that the proposed UAV based measurement system will improve measurement accuracy and enhanced geographic performance over conventional automotive vehicle based measurement systems / Master of Science / Wireless networks have grown to support vital and everyday processes in modern society. The COVID-19 pandemic proved wireless communication means a necessity to limit daily disruptions, but networks had already been supporting a continuously increasing amount of mobile devices prior to this. Other demonstrations of wireless network capacity include the release of 5G technology, allowing improved performance with traditional devices like smartphones, along with additional use cases this technology enables including the internet-of-things (IoT) and artificial intelligence (AI) leveraged functions for commercial applications. While wireless network capabilities have demonstrated their success in supporting and maintaining some critical functions, it is important to continually look ahead and plan for future network implementations in order to develop and support all desired advancements. Current measurement methods that assist in verifying coverage for current use cases like mobile devices will fall short in verification for more stringent requirements characteristic of AV and other ambitious network goals. The results found in this work then support the need for continuing research of a UAV-leveraged platform in the scope of eventual practical and safe AV integration into society. The focus of this thesis is to then propose and provide initial evaluation of a UAV-leveraged measurement platform to verify the operability of autonomous vehicles (AVs), which are expected to be a major aspect of future network processes. The computational requirements to operate an autonomous vehicle exponentially increase as a vehicle's autonomy level is increased. 5G is then expected to play an integral role in offloading certain vehicle tasks to the cloud. This thesis paper then proposes UAV based measurement opportunities as a method to characterize 5G coverage as part of autonomous vehicle processes to identify the proper level of autonomy that can operate safely given the current RF environment.

Over recent years, the research and studies have focused on innovative solutions in various aspects and phases related to the high demands on data rate and energy for fifth-generation and beyond (B5G). This thesis aims to improve the energy efficiency, error rates, low-resolution ADCs/DACs, antenna array structures and sum-rate performances of a single cell downlink broadband millimetre-wave (mmWave) systems with orthogonal frequency division multiplexing (OFDM) modulation and deploying multi-user massive multiple inputs multiple outputs (MU mMIMO) by applying robust beamforming techniques and detection algorithms that support multiple streams per user (UE) in various environments and scenarios to achieve low complexity system design with reliable performance and significant improvement in users perceived quality of service (QoS). The performance of the four 5G candidate mmWave frequencies, 28 GHz, 39 GHz, 60 GHz, and 73 GHz, are investigated for indoor/outdoor propagation scenarios, including path loss models and multipath delay spread values. Results are compared to confirm that the received power and delay spread is decreased with increasing frequency. The results were also validated with the measurement findings for 60 GHz. Then several proposed design models of beamforming are studied and implemented modified algorithms of Hybrid Beamforming (HBF) approaches in indoor/outdoor scenarios over large scale fading wideband mmWave /Raleigh channels. Firstly, three beamforming based diagonalize the Equivalent Virtual Channel Matrix (EVCM) schemes with the optimal linear combining methods are presented to overcoming the self-interference problems in Quasi-Orthogonal-Space Time Block Code (QO-STBC) systems over narrowband mmWave Single-User mMIMO (SU mMIMO). The evaluated results show that the proposed beamforming based- Single Value Decomposition (SVD) outperforms the conventional beamforming and standard QO-STBC techniques in terms of BER and spectrum efficiency. Next, the proposed HBF algorithm approaches with the fully/ partially connected structures are developed and applied for sum-rate and symbol error rate (SER) performance maximization MU mMIMO-OFDM system, including HBF based on block diagonalization (BD) method Constraint/Unconstraint RF Power, Codebook, Kalman schemes. In addition, the modified near optimal linear HBF-Zero Forcing (HBF-ZF) and HBF-Minimum Mean Square Error (HBF MMSE) schemes, considering both fully-connected and partially-connected structures. Finally, Simulation results using MATLAB platform, demonstrate that the proposed HBF based codebook and most likely HBF based-unconstraint RF power algorithms achieve significant performance gains in terms SER and sum-rate efficiency as well as show high immunity against the deformities and disturbances in the system compared with other HBF algorithm schemes. / Ministry of Higher Education and Scientific Research, the Republic of Iraq

Radars have been under steady development to track, identify, image, and classify targets. Modern radar systems, with the help of embedded systems, have additional comprehensive signal processing capabilities. They can extract useful information from very noisy data, e.g. interference from the environment and unwanted echoes which is collectively known as clutter in radar terms. Concerning the healthcare industry, radar applications for detection of vital signs, i.e. breathing and heart rate, have been extensively developed during the last few decades. Modern radar systems are expected to be a large part of non-intrusive monitoring in the coming smart home industry, where vital signs need to be monitored in the currently aging population. The research presented here is to break new ground in the radar-based healthcare technology, enabling detection of cold-induced shivering to such level that the micro-shivering can be clearly identified. To simplify the radar software optimization, a commercially available radar kit with demo application and a muscle model system using a vibration generator is used. The model is quantified through precise measurements. A simulated human body vital sign plus shivering is applied. By optimizing the radar software, the shivering amplitude and frequency are measured.

Abstract With the unprecedented growth in mobile data traffic and network densification, the emerging fifth-generation (5G) wireless network warrants a paradigm shift with respect to system design and technological enablers. In this regard, the prime motivation of this thesis is to propose an integrated access-backhaul (IAB) framework to dynamically schedule users, while efficiently providing a wireless backhaul to dense small cells and mitigating interference. In addition, joint resource allocation and interference mitigation solutions are proposed for two-hop and multi-hop self-backhauled millimeter wave (mmWave) networks. The first contribution of this thesis focuses on a multi-user two-hop relay cellular system in which a massive antenna array enabled macro base station (BS) simultaneously provides high beamforming gains to outdoor users, and wireless backhauling to outdoor small cells. Moreover, a hierarchical interference mitigation scheme is applied to efficiently mitigate cross-tier and co-tier interference. In the second contribution, a multi-hop self-backhauled mmWave communication scenario is studied whereby a joint multi-hop multi-path selection and rate allocation framework is proposed to enable Gbps data rates with reliable communications. Using reinforcement learning techniques, a dynamic and efficient re-routing solution is proposed to cope with blockage and latency constraints. Finally, a risk-sensitive learning solution is leveraged to provide high-reliability and low-latency communications. In summary, the dissertation analyses key trade-offs between (i) capacity and latency, (ii) reliability and network density. Extensive simulation results were carried out to verify the performance gains of the proposed algorithms compared to several baselines and for different network settings. Key findings show significant improvements in terms of higher data rates, lower latency, and reliable communications with some trade-offs. / Tiivistelmä Liikkuvan dataliikenteen ennennäkemättömän kasvun ja verkkojen tihentymisen seurauksena pian käyttöön tulevien viidennen sukupolven (5G) langattomien verkkojen järjestelmäsuunnittelua ja teknologisten mahdollistajien käyttöä on täytynyt lähestyä kokonaan uudesta näkökulmasta. Niinpä tämän väitöstyön johtavana ajatuksena on ehdottaa integroitua verkkoon pääsyn ja runkoverkkoyhteyden muodostamismallia, jossa käyttäjät resursoidaan dynaamisesti ja samalla muodostetaan tehokkaat runkoverkkoyhteydet piensoluille. Tätä varten tutkitaan resurssiallokaation ja häiriöiden lieventämisen yhteisratkaisuja, jotka tukevat kahden tai useamman hypyn yhteyksiä ja samanaikaista runkoverkkoyhteyden luomista millimetriaaltoalueen verkoissa. Työn alkuosa keskittyy usean käyttäjän välitinavusteiseen kahden hypyn solukkoverkkoon, jossa makrotukiasemassa käytetään suurta antenniryhmää muodostamaan samanaikaisesti suuren vahvistuksen antennikeiloja käyttäjälinkeille ja langattomalle runkoyhteysosuudelle. Lisäksi sovelletaan hierarkkista häiriönvaimennusmenetelmää saman kerroksen ja kerrosten välisen häiriön tehokkaaseen vähentämiseen. Työn seuraavassa osassa arvioidaan usean hypyn runkoverkkoyhteyden muodostuksen tutkimusongelmaa millimetrialueen kommunikaatiossa kehittämällä yhdistetty menetelmä usean hypyn monipolkuvalinnalle ja tiedonsiirtoresurssien allokoinnille. Tällä tähdätään gigabittiluokan datanopeuksiin ja luotettavaan tietoliikenteeseen millimetrialueella. Vahvistavan oppimisen tekniikan avulla esitellään dynaaminen ja tehokas uudelleenreitityskonsepti toimimaan esto- ja viiverajoitusten kanssa. Lopuksi hyödynnetään riskisensitiivistä oppimista ja antennidiversiteettitekniikoita suuren luotettavuuden ja pienen latenssin saavuttamiseksi millimetrialueen tiedonsiirrossa. Näiden avulla analysoidaan kaupankäyntiä esimerkiksi (i) kapasiteetin ja latenssin sekä (ii) luotettavuuden ja verkon tiheyden/kuormituksen välillä. Mittavien suoritettujen simulointien avulla osoitetaan ehdotettujen algoritmien suorituskykyedut suhteessa tunnettuihin verrokkeihin useissa eri skenaarioissa. Tulosten perusteella saavutetaan merkittäviä kustannussäästöjä infrastruktuurin ja runkoverkon osalta sekä päästään suuriin datanopeuksiin ja parannuksiin pienen latenssin luotettavassa tietoliikenteessä.

In the thesis, the user body effect on antennas in a mobile terminal is discussed. In order to overcome the degradation of Multiple-Input Multiple-Output (MIMO) performance due to the user body effect, a quad-elements MIMO antenna array which can mitigate the body effect through an adaptive antenna switching method is introduced for 4G mobile terminals. In addition, various bezel MIMO antennas that are robust to the impedance mismatching caused by the user effect have also been presented. The study of user body effect is later extended to frequency bands at 15 GHz and 28 GHz for future 5G communication systems. The results reveal that a human body will cause a significant shadowing loss, which will be a critical loss in 5G cellular networks. The electromagnetic field (EMF) exposure of a mobile terminal is also studied in this thesis. Below 6 GHz, the simultaneous transmission specific absorption rate (SAR) for MIMO antennas is the primary concern due to its complicated assessment procedures. Above 6 GHz, the free space power density is adopted as the basic parameter of exposure limits globally, and preliminary studies have been presented to address major challenges in EMF exposure assessment for 5G mobile terminals. / <p>QC 20171005</p>