Analog radio over fiber solutions for multi-band 5g systems

This study presents radio over fiber (RoF) solutions for the fifth-generation (5G) of wireless networks. After the state of the art and a technical background review, four main contributions are reported. The first one is proposing and investigating a RoF technique based on a dual-drive Mach-Zehnder modulator (DD-MZM) for multi-band mobile fronthauls, in which two radiofrequency (RF) signals in the predicted 5G bands individually feed an arm of the optical modulator. Experimental results demonstrate the approach enhances the RF interference mitigation and can prevail over traditional methods. The second contribution comprises the integration of a 5G transceiver, previously developed by our group, in a passive optical network (PON) using RoF technology and wavelength division multiplexing (WDM) overlay. The proposed architecture innovates by employing DD-MZM and enables to simultaneously transport baseband and 5G candidate RF signals in the same PON infrastructure. The proof-of-concept includes the transmission of a generalized frequency division multiplexing (GFDM) signal generated by the 5G transceiver in the 700 MHz band, a 26 GHz digitally modulated signal as a millimeter-waves 5G band, and a baseband signal from an gigabit PON (GPON). Experimental results demonstrate the 5G transceiver digital performance when using RoF technology for distributing the GFDM signal, as well as Gbit/s throughput at 26 GHz. The third contribution is the implementation of a flexible-waveform and multi-application fiber-wireless (FiWi) system toward 5G. Such system includes the FiWi transmission of the GFDM and filtered orthogonal frequency division multiplexing (F-OFDM) signals at 788 MHz, toward long-range cells for remote or rural mobile access, as well as the recently launched 5G NR standard in microwave and mm-waves, aiming enhanced mobile broadband indoor and outdoor applications. Digital signal processing (DSP) is used for selecting the waveform and linearizing the RoF link. Experimental results demonstrate the suitability of the proposed solution to address 5G scenarios and requirements, besides the applicability of using existent fiber-to-the-home (FTTH) networks from Internet service providers for implementing 5G systems. Finally, the fourth contribution is the implementation of a multi-band 5G NR system with photonic-assisted RF amplification (PAA). The approach takes advantage of a novel PAA technique, based on RoF technology and four-wave mixing effect, that allows straightforward integration to the transport networks. Experimental results demonstrate iv uniform and stable 15 dB wideband gain for Long Term Evolution (LTE) and three 5G signals, distributed in the frequency range from 780 MHz to 26 GHz and coexisting in the mobile fronthaul. The obtained digital performance has efficiently met the Third-Generation Partnership Project (3GPP) requirements, demonstrating the applicability of the proposed approach for using fiber-optic links to distribute and jointly amplify LTE and 5G signals in the optical domain.Agência 1Este trabalho apresenta soluções de rádio sobre fibra (RoF) para aplicações em redes sem fio de quinta geração (5G), e inclui quatro contribuições principais. A primeira delas refere-se à proposta e investigação de uma técnica de RoF baseada no modulador eletroóptico de braço duplo, dual-drive Mach-Zehnder (DD-MZM), para a transmissão simultânea de sinais de radiofrequência (RF) em bandas previstas para redes 5G. Resultados experimentais demonstram que o uso do DD-MZM favorece a ausência de interferência entre os sinais de RF transmitidos. A segunda contribuição trata da integração de um transceptor de RF, desenvolvido para aplicações 5G e apto a prover a forma de onda conhecida como generalized frequency division multiplexing (GFDM), em uma rede óptica passiva (PON) ao utilizar RoF e multiplexação por divisão de comprimento de onda (WDM). A arquitetura proposta permite transportar, na mesma infraestrutura de rede, sinais em banda base e de radiofrequência nas faixas do espectro candidatas para 5G. A prova de conceito inclui a distribuição conjunta de três tipos de sinais: um sinal GFDM na banda de 700 MHz, proveniente do transceptor desenvolvido; um sinal digital na frequência de 26 GHz, assumindo a faixa de ondas milimétricas; sinais em banda base provenientes de uma PON dedicada ao serviço de Internet. Resultados experimentais demonstram o desempenho do transceptor de RF ao utilizar a referida arquitetura para distribuir sinais GFDM, além de taxas de transmissão de dados da ordem de Gbit/s na faixa de 26 GHz. A terceira contribuição corresponde à implementação de um sistema fibra/rádio potencial para redes 5G, operando inclusive com o padrão ―5G New Radio (5G NR)‖ nas faixas de micro-ondas e ondas milimétricas. Tal sistema é capaz de prover macro células na banda de 700 MHz para aplicações de longo alcance e/ou rurais, utilizando sinais GFDM ou filtered orthogonal frequency division multiplexing (F-OFDM), assim como femto células na banda de 26 GHz, destinada a altas taxas de transmissão de dados para comunicações de curto alcance. Resultados experimentais demonstram a aplicabilidade da solução proposta para redes 5G, além da viabilidade de utilizar redes ópticas pertencentes a provedores de Internet para favorecer sistemas de nova geração. Por fim, a quarta contribuição trata da implementação de um sistema 5G NR multibanda, assistido por amplificação de RF no domínio óptico. Esse sistema faz uso de um novo método de amplificação, baseado no efeito não linear da mistura de quatro ondas, que vi permite integração direta em redes de transporte envolvendo rádio sobre fibra. Resultados experimentais demonstram ganho de RF igual a 15 dB em uma ampla faixa de frequências (700 MHz até 26 GHz), atendendo simultaneamente tecnologias de quarta e quinta geração. O desempenho digital obtido atendeu aos requisitos estabelecidos pela 3GPP (Third-Generation Partnership Project), indicando a aplicabilidade da solução em questão para distribuir e conjuntamente amplificar sinais de RF em enlaces de fibra óptica

Study of efficient transmission and reception of image-type data using millimeter waves

Evaluation of signal processing and modulation techniques for transmission and reception of image type data via millimeter wave relay satellite

Advanced Trends in Wireless Communications

Physical limitations on wireless communication channels impose huge challenges to reliable communication. Bandwidth limitations, propagation loss, noise and interference make the wireless channel a narrow pipe that does not readily accommodate rapid flow of data. Thus, researches aim to design systems that are suitable to operate in such channels, in order to have high performance quality of service. Also, the mobility of the communication systems requires further investigations to reduce the complexity and the power consumption of the receiver. This book aims to provide highlights of the current research in the field of wireless communications. The subjects discussed are very valuable to communication researchers rather than researchers in the wireless related areas. The book chapters cover a wide range of wireless communication topics

Retournement temporel : application aux réseaux mobiles

This thesis studies the time reversal technique to improve the energy efficiency of future mobile networks and reduce the cost of future mobile devices. Time reversal technique consists in using the time inverse of the propagation channel impulse response (between a transceiver and a receiver) as a prefilter. Such pre-filtered signal is received with a stronger power (this is spatial focusing) and with a strong main echo, relatively to secondary echoes (this is time compression). During a previous learning phase, the transceiver estimates the channel by measuring the pilot signal emitted by the receiver. Space-time focusing is obtained only at the condition that the propagation remains identical between the learning phase and the data transmission phase: this is the ‘channel reciprocity’ condition. Numerous works show that spatial focusing allows for the reduction of the required transmit power for a given target received power, on the one hand, and that time compression allow for the reduction of the required complexity at the receiver side to handle multiple echoes, on the other hand. However, studies on complexity reduction are limited to ultra wideband. Some works of this thesis (based on simulations and experimental measurements) show that, for bands which are more typical for future networks (a carrier frequency of 1GHz and a spectrum of 30 MHz to 100 MHz), thanks to time reversal, a simple receiver and a mono-carrier signal are sufficient to reach high data rates. Moreover, the channel reciprocity condition is not verified in two scenarios which are typical from mobile networks. Firstly, in most European mobile networks, the frequency division duplex mode is used. This mode implies that the transceiver and the receiver communicate on distinct carriers, and therefore through different propagation channels. Secondly, when considering a receiver on a moving connected vehicle, the transceiver and the receiver communicate one with each other at distinct instants, corresponding to distinct positions of the vehicles, and therefore through different propagation channels. Some works of this thesis propose solutions to obtain space-time focusing for these two scenarios. Finally, some works of this thesis explore the combination of time reversal with other recent signal processing techniques (spatial modulation, on the one hand, a new multi-carrier waveform, on the other hand), or new deployment scenarios (millimeter waves and large antenna arrays to interconnect the nodes of an ultra dense network) or new applications (guidance and navigation) which can be envisaged for future mobile networks.Cette thèse étudie la technique dite de ‘Retournement Temporel’ afin d’améliorer l’efficacité énergétique des futurs réseaux mobiles d’une part, et réduire le coût des futurs terminaux mobiles, d’autre part. Le retournement temporel consiste à utiliser l’inverse temporel de la réponse impulsionnelle du canal de propagation entre un émetteur et un récepteur pour préfiltrer l’émission d’un signal de données. Avantageusement, le signal ainsi préfiltré est reçu avec une puissance renforcée (c’est la focalisation spatiale) et un écho principal qui est renforcé par rapport aux échos secondaires (c’est la compression temporelle). Lors d’une étape préalable d’apprentissage, l’émetteur estime le canal en mesurant un signal pilote provenant du récepteur. La focalisation spatiotemporelle n’est obtenue qu’à condition que la propagation demeure identique entre la phase d’apprentissage et la phase de transmission de données : c’est la condition de ‘réciprocité du canal’. De nombreux travaux montrent que la focalisation spatiale permet de réduire la puissance émise nécessaire pour atteindre une puissance cible au récepteur d’une part, et que la compression temporelle permet de réduire la complexité du récepteur nécessaire pour gérer l’effet des échos multiples, d’autre part. Cependant, les études sur la réduction de la complexité du récepteur se limitent à l’ultra large bande. Des travaux de cette thèse (basés sur des simulations et des mesures expérimentales) montrent que pour des bandes de fréquences plus typiques des futurs réseaux mobiles (fréquence porteuse à 1GHz et spectre de 30 MHz à 100 MHz), grâce au retournement temporel, un récepteur simple et un signal monoporteuse suffisent pour atteindre de hauts débits. En outre, la condition de réciprocité du canal n’est pas vérifiée dans deux scénarios typiques des réseaux mobiles. Tout d’abord, dans la plupart des réseaux mobiles européens, le mode de duplex en fréquence est utilisé. Ce mode implique que l’émetteur et le récepteur communiquent l’un avec l’autre sur des fréquences porteuses distinctes, et donc à travers des canaux de propagations différents. De plus, lorsqu’on considère un récepteur sur un véhicule connecté en mouvement, l’émetteur et le récepteur communiquent l’un avec l’autre à des instants distincts, correspondants à des positions distinctes du véhicule, et donc à travers des canaux de propagations différents. Des travaux de cette thèse proposent des solutions pour obtenir la focalisation spatio-temporelle dans ces deux scenarios. Enfin, des travaux de la thèse explorent la combinaison du retournement temporel avec d’autres techniques de traitement de signal récentes (la modulation spatiale, d’une part, et une nouvelle forme d’onde multiporteuse, d’autre part), ou des scenarios de déploiement nouveaux (ondes millimétriques et très grands réseaux d’antennes pour inter-connecter les noeuds d’un réseau ultra dense) ou de nouvelles applications (guidage et navigation) envisageables pour les futurs réseaux mobiles

60 GHz Wireless Propagation Channels: Characterization, Modeling and Evaluation

To be able to connect wirelessly to the internet is nowadays a part of everyday life and the number of wireless devices accessing wireless networks worldwide are increasing rapidly. However, with the increasing number of wireless devices and applications and the amount available bandwidth, spectrum shortage is an issue. A promising way to increase the amount of available spectrum is to utilize frequency bands in the mm-wave range of 30-300 GHz that previously have not been used for typical consumer applications. The 60 GHz band has been pointed out as a good candidate for short range, high data rate communications, as the amount of available bandwidth is at least 5 GHz worldwide, with most countries having 7 GHz of bandwidth available in this band. This large bandwidth is expected to allow for wireless communication with bit rates up to 7 Gbit/s, which can be compared to the typical WLAN systems of today that typically provide bit rates up to 0.6 Gbit/s. However, the performance of any wireless system is highly dependent on the properties and characteristics of the wireless propagation channel. This thesis focuses on indoor short range wireless propagation channels in the 60 GHz band and contains a collection of papers that characterizes, models and evaluates different aspects that are directly related to the propagation channel properties. Paper I investigates the directional properties of the indoor 60 GHz wireless radio channel based on a set of indoor measurements in a conference room. In the paper, the signal pathways and propagation mechanisms for the strongest paths are identified. The results show that first and second order interactions account for the major contribution of the received power. The results also show that finer structures, such as ceiling lamps, can be significant interacting objects. Paper II presents a cluster-based double-directional channel model for 60 GHz indoor multiple-input multiple-output (MIMO) systems. This paper is a direct continuation of the results in paper I. The model supports arbitrary antenna elements and array configurations and is validated against measurement data. The validation shows that the channel model is able to efficiently reproduce the statistical properties of the measured channels. The presented channel model is also compared with the 60 GHz channel models developed for the industry standards IEEE802.15.3c and IEEE802.11ad. Paper III characterizes the effect of shadowing due to humans and other objects. Measurements of the shadowing gain for human legs, metallic sheets, as well as metallic and plastic cylinders are presented. It is shown that the shadowing gain of these objects are fairly similar and that the shadowing due to the metal cylinder can be determined based on the geometrical theory of diffraction. Next, the shadowing due to a water-filled human body phantom is compared with the shadowing due to real humans. The results show that the water-filled phantom has shadowing properties similar to those of humans and is therefore suitable for use in 60 GHz human body shadowing measurements. Paper IV presents a novel way of estimating the cluster decay and fading. Previously, the cluster decay has usually been determined by performing a simple linear regression, without considering the effects of the noise floor and cluster fading. The paper presents an estimation method which takes these effects into account and jointly estimates both the cluster decay and cluster fading. It is shown that this estimation method can greatly improve the estimated parameters. Paper V evaluates the capacity improvement capability of spatial multiplexing and beamforming techniques for 60 GHz systems in an indoor environment. In this paper, beamforming refers to conventional gain focusing in the direction of the strongest propagation path. The paper uses a capacity metric that only depends on the multi-path richness of the propagation channel and the antenna aperture size. In the paper, it is shown that, when the link budget is limited due to electrically small antennas and long Tx-Rx separation distances, beamforming approximates the capacity of spatial multiplexing. However, spatial multiplexing is a worthwhile option when Rx SNR is favorable and a higher peak data rate is required. Paper VI describes different methods for the clustering of wireless multi-path components. In the literature, the clustering method that is predominantly used is the K-means algorithm, or a power-weighted version of K-means, called K-power means. In this paper, we point out that K-means is a special case of a Gaussian mixture model (GMM). The paper presents a clustering method based on a GMM. This method is able to handle arbitrary cluster spreads in the different dimensions better than the K-means algorithm. A power-weighted version of the GMM is also presented. In addition to this, a mixture model based on asymmetric Laplace distributions is also presented, with and without power-weighting. Paper VII is based on channel measurements in a small and a large room, where the Tx and Rx arrays have dual polarized elements. Using these measurements, the cross-polarization ratio (XPR) of the multi-path components are characterized. This gives valuable information on how the MPCs are affected by the propagation channel. A statistical description of the XPR is also needed for the development of a propagation channel model that supports polarization. The paper also investigates the eigenvalue spreads for single and dual polarized elements. Furthermore, the measurements include LOS and NLOS measurement, where the NLOS scenarios include water-filled human presented in paper III. The results show that the capacity can be greatly improved if dual-polarized elements are used, and that the XPR values are in general higher compared to lower frequencies

Design of Reconfigurable Intelligent Surfaces for Wireless Communication: A Review

Existing literature reviews predominantly focus on the theoretical aspects of reconfigurable intelligent surfaces (RISs), such as algorithms and models, while neglecting a thorough examination of the associated hardware components. To bridge this gap, this research paper presents a comprehensive overview of the hardware structure of RISs. The paper provides a classification of RIS cell designs and prototype systems, offering insights into the diverse configurations and functionalities. Moreover, the study explores potential future directions for RIS development. Notably, a novel RIS prototype design is introduced, which integrates seamlessly with a communication system for performance evaluation through signal gain and image formation experiments. The results demonstrate the significant potential of RISs in enhancing communication quality within signal blind zones and facilitating effective radio wave imaging

Waveplates based on metasurfaces in the THz range

Los platos de onda basados en metasuperficies son componentes clave en electromagnetismo, ya que permiten un control total de la polarización de las ondas electromagnéticas con la ventaja de presentar estructuras más compactas que los platos de onda convencionales. Además, la aplicación del principio de Pancharatnam Berry (PB) a los platos de media onda (HWP) basados en metasuperficies, permite la manipulación de frentes de onda junto con la conversión de la polarización de las ondas incidentes circularmente polarizadas, simplemente girando los meta-átomos que componen la metasuperficie. Para lograr altos niveles de eficiencia de transmisión con platos de onda basados en metasuperficies, generalmente se requieren diseños multicapa. Esto implica estructuras voluminosas y complica el proceso de fabricación, restando importancia a la ventaja de utilizar metasuperficies. El propósito de esta tesis realizada en la Universidad Pública de Navarra y en L’École Polytechnique Fédérale de Lausanne, Suiza (EPFL) es ofrecer una ventaja tecnológica tanto para el control de polarización como para la manipulación del frente de onda y contribuir al desarrollo de dispositivos basados en metamasuperficies, incluyendo su fabricación y verificación experimental. Los resultados incluyen lo siguiente: Un plato de media onda operando en transmisión, ultradelgado y basado en una metasuperficie en zigzag de dos capas que opera en la parte baja del espectro del THz con un 90% de eficiencia de transmisión, que se demuestra numérica y experimentalmente. Se lleva a cabo un análisis detallado de la robustez del dispositivo con respecto a los desalineamientos de las capas mediante el diseño y la fabricación de dos dispositivos adicionales con el máximo desalineamiento entre capas en ambas direcciones transversales. Una metalente ultradelgada y compacta basada en el principio Pancharatnam Berry con solo dos capas alcanzando un 90% de eficiencia de transmisión, enfocando el frente de onda de una onda incidente polarizada circularmente y convirtiendo su polarización. La estructura es estudiada semi-analítica y numéricamente y medida experimentalmente, comprobándose un excelente comportamiento como HWP PB metalente a 87 GHz. Una aplicación de ingeniería de frentes de onda para la manipulación de los mismos se demuestra numéricamente en el rango de ondas milimétricas mediante la integración de la metalente en un sistema de antena-metalente, que se estudia semi-analíticamente y se corrobora experimentalmente. El sistema convierte la polarización de las ondas polarizadas circularmente, logrando un incremento de la directividad de antena de 17 dB a ⁓35 dB a 87 GHz con un AR inferior a 0.5 dB. Finalmente, se presentan dos configuraciones extra del sistema para trabajar entre los extremos del rango de frecuencia comprendido entre 75 GHz y 105 GHz, con directividades ⁓32 dB y AR < 3 dB.Transmissive waveplates based on metasurfaces are key components in electromagnetism, as they allow for a full control of the electromagnetic wave polarization with the advantage of presenting structures more compact than conventional waveplates. Moreover, applying the Pancharatnam Berry (PB) principle to half-wave plate (HWP) metasurfaces allows the manipulation of wavefronts along with the conversion of the handedness of circularly polarized incident waves by simply rotating the meta-atoms that compose the metasurface. For achieving high levels of transmission efficiency with transmissive waveplates based on metasurfaces, multiple layer designs are usually required. It implies bulky structures and complicates the fabrication process, downplaying the aim of the use of metasurfaces. The purpose of this thesis performed at the Public University of Navarre and at École Polytechnique Fédérale de Lausanne (EPFL) is to offer a technological advantage both for polarization controlling as wavefront manipulation and contribute to the development of metasurface-based devices, including their fabrication and experimental verification. The results include the following: An ultrathin transmissive half-wave plate based on a bi-layered zigzag metasurface operating at the lower-frequency edge of the THz spectrum with a 90% of transmission efficiency, which is numerically and experimentally demonstrated. A detailed analysis of the device robustness with respect to layer misalignments is carried out by designing and fabricating two additional devices with the maximum possible shift between layers along both transverse directions. A compact ultrathin metalens based on the Pancharatnam Berry principle with only two layers with a 90% of transmission efficiency, focusing the wavefront of a circularly polarized incident wave and converting its handedness. The structure is semi-analytically and numerically studied and experimentally measured, verifying an excellent behavior as HWP PB metalens at 87 GHz. A wavefront engineering application for wavefront manipulation is numerically demonstrated in the millimeter-wave range by the integration of the metalens in an antenna-metalens system, which is semi-analytically studied and experimentally corroborated. The system converts the handedness of circular polarized waves, achieving an increment of the antenna directivity from17 dB to ⁓35 dB at 87 GHz with an AR lesser than 0.5 dB. Finally, two extra system configurations are presented to work around the frequency range extremes comprised between 75 GHz and 105 GHz, with directivities ⁓32 dB and AR < 3 dB.Programa de Doctorado en Tecnologías de las Comunicaciones, Bioingeniería y de las Energías Renovables (RD 99/2011)Bioingeniaritzako eta Komunikazioen eta Energia Berriztagarrien Teknologietako Doktoretza Programa (ED 99/2011

Metamaterials and their applications towards novel imaging technologies

Thesis advisor: Willie J. PadillaThis thesis will describe the implementation of novel imaging applications with electromagnetic metamaterials. Metamaterials have proven to be host to a multitude of interesting physical phenomena and give rich insight electromagnetic theory. This thesis will explore not only the physical theory that give them their interesting electromagnetic properties, but also the many applications of metamaterials. There is a strong need for efficient, low cost imaging solutions, specifically in the longer wavelength regime. While this technology has often been at a standstill due to the lack of natural materials that can effectively operate at these wavelengths, metamaterials have revolutionized the creation of devices to fit these needs. Their scalability has allowed them to access regimes of the electromagnetic spectrum previously unobtainable with natural materials. Along with metamaterials, mathematical techniques can be utilized to make these imaging systems streamlined and effective. Chapter 1 gives a background not only to metamaterials, but also details several parts of general electromagnetic theory that are important for the understanding of metamaterial theory. Chapter 2 discusses one of the most ubiquitous types of metamaterials, the metamaterial absorber, examining not only its physical mechanism, but also its role in metamaterial devices. Chapter 3 gives a theoretical background of imaging at longer wavelengths, specifically single pixel imaging. Chapter 3 also discusses the theory of Compressive Sensing, a mathematical construct that has allowed sampling rates that can exceed the Nyquist Limit. Chapter 4 discusses work that utilizes photoexcitation of a semiconductor to modulate THz radiation. These physical methods were used to create a dynamic THz spatial light modulator and implemented in a single pixel imaging system in the THz regime. Chapter 5 examines active metamaterial modulation through depletion of carriers in a doped semiconductor via application of a bias voltage and its implementation into a similar single pixel imaging system. Additionally, novel techniques are used to access masks generally unobtainable by traditional single pixel imagers. Chapter 6 discusses a completely novel way to encode spatial masks in frequency, rather than time, to create a completely passive millimeter wave imager. Chapter 7 details the use of telecommunication techniques in a novel way to reduce image acquisition time and further streamline the THz single pixel imager. Finally, Chapter 8 will discuss some future outlooks and draw some conclusions from the work that has been done.Thesis (PhD) — Boston College, 2015.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Physics

Keilaavan millimetriaaltoradiolinkin suuntaaminen ja seuraaminen

In order to provide high-throughput mobile broadband in a dense urban information society, upcoming cellular networks will finally employ the under-utilized millimeter-wave (mmW) frequencies. The challenging mmW radio environment, however, necessitates massive cell densification with wireless backhauling using very directional links. This thesis investigates how these links between access points may be aligned efficiently, and how alignment reflects the network organization. The work provides a thorough presentation of different high-level aspects and background information required when designing a mmW small cell system. In terms of alignment functionality, both automatic link establishment and proactive tracking are considered. Additionally, the presentation includes an overview of beam steerable antennas, mmW propagation in urban environments, and network organization. The thesis further specifies requirements, proposes possible approaches and compares those with existing implementations. Most of existing mmW beam alignment solutions are intended for short-range indoor communications and do not address the issues in cellular systems. While existing functionality considers only a single link between two devices, efficient design should consider both the entire network and the underlying phenomena. The devices should further exploit the existing network infrastructure, location and orientation information, and the concepts of machine learning. Even though the world has recently seen advancements in the related fields, there is still much work to be done before commercial deployment is possible.Seuraavan sukupolven matkaviestinjärjestelmien erittäin nopeissa datayhteyksissä tullaan hyödyntämään millimetriaaltoteknologiaa. Näillä taajuuksilla radioympäristö on kuitenkin hyvin haastava, mikä edellyttää verkon solutiheyden moninkertaistamista, täysin langattomia tukiasemia ja erittäin suuntaavia antenneja. Tässä diplomityössä tutkitaan eri keinoja kuinka tukiasemien väliset linkit kohdistetaan tehokkaasti, ja miten se vaikuttaa verkon rakenteeseen ja hallintaan. Työ tarjoaa kattavan taustaselvityksen mm-aaltosoluverkon toteuttamiseen tarvittavista asioista. Keilanohjausta tarkastellaan sekä verkon automaattisen laajentamisen että kohteen aktiivisen seurauksen kannalta. Tämän lisäksi työssä tutkitaan keilattavia antenneja, mm-aaltojen etenemistä kaupunkiympäristöissä ja verkkorakennetta. Näiden lisäksi työssä rajataan edellytykset, esitetään mahdollisia ratkaisuja, ja vertaillaan näitä olemassa oleviin toteutuksiin. Nykyiset keilaustoteutukset ovat pääasiassa suunniteltu lyhyen kantaman sisäyhteyksille, eivätkä siten vastaa ongelman asettelua. Aikaisempi toiminnallisuus keskittyy yhteen ainoaan linkkiin vaikka tehokas toteutus huomioisi koko järjestelmän kohdistusongelman fysikaalista perustaa unohtamatta. Verkkolaitteiden tulisi hyödyntää olemassa olevaa radioverkkoa, sekä paikka- että suuntatietoja, ja koneoppimisen keinoja. Vaikka aiheeseen liittyvä teknologia on kehittynyt viime vuosina harppauksin, mm-aaltosoluverkot ovat kaikkea muuta kuin valmiita markkinoille

Uplink data measurement and analysis for 5G eCPRI radio unit

Abstract. The new 5G mobile network generation aims to enhance the performance of the cellular network in almost every possible aspect, offering higher data rates, lower latencies, and massive number of network connections. Arguably the most important change from LTE are the new RU-BBU split options for 5G promoted by 3GPP and other organizations. Another big conceptual shift introduced with 5G is the open RAN concept, pushed forward by organizations such as the O-RAN alliance. O-RAN aims to standardize the interfaces between different RAN elements in a way that promotes vendor interoperability and lowers the entry barrier for new equipment suppliers. Moreover, the 7-2x split option standardized by O-RAN has risen as the most important option within the different low layer split options. As the fronthaul interface, O-RAN has selected the packet-based eCPRI protocol, which has been designed to be more flexible and dynamic in terms of transport network and data-rates compared to its predecessor CPRI. Due to being a new interface, tools to analyse data from this interface are lacking. In this thesis, a new, Python-based data analysis tool for UL eCPRI data was created for data quality validation purposes from any O-RAN 7-2x functional split based 5G eCPRI radio unit. The main goal for this was to provide concrete KPIs from captured data, including timing offset, signal power level and error vector magnitude. The tool produces visual and text-based outputs that can be used in both manual and automated testing. The tool has enhanced eCPRI UL datapath testing in radio unit integration teams by providing actual quality metrics and enabling test automation.Uplink datamittaukset ja -analyysi 5G eCPRI radiolla. Tiivistelmä. Uusi 5G mobiiliverkkogeneraatio tuo mukanaan parannuksia lähes kaikkiin mobiiliverkon ominaisuuksiin, tarjoten nopeamman datasiirron, pienemmät viiveet ja valtavat laiteverkostot. Luultavasti tärkein muutos LTE teknologiasta ovat 3GPP:n ja muiden organisaatioiden ehdottamat uudet radion ja systeemimoduulin väliset funktionaaliset jakovaihtoehdot. Toinen huomattava muutos 5G:ssä on O-RAN:in ajama avoimen RAN:in konsepti, jonka tarkoituksena on standardisoida verkkolaitteiden väliset rajapinnat niin, että RAN voidaan rakentaa eri valmistajien laitteista, laskien uusien laitevalmistajien kynnystä astua verkkolaitemarkkinoille. O-RAN:n standardisoima 7-2x funktionaalinen jako on noussut tärkeimmäksi alemman tason jakovaihtoehdoista. Fronthaul rajapinnan protokollaksi O-RAN on valinnut pakettitiedonsiirtoon perustuvan eCPRI:n, joka on suunniteltu dynaamisemmaksi ja joustavammaksi datanopeuksien ja lähetysverkon suhteen kuin edeltävä CPRI protokolla. Uutena protokollana, eCPRI rajapinnalle soveltuvia data-analyysityökaluja ei ole juurikaan saatavilla. Tässä työssä luotiin uusi pythonpohjainen data-analyysityökalu UL suunnan eCPRI datalle, jotta datan laatu voidaan määrittää millä tahansa O-RAN 7-2x funktionaaliseen jakoon perustuvalla 5G eCPRI radiolla. Työkalun päätarkoitus on analysoida ja kuvata datan laatua laskemalla datan ajoitusoffsettia, tehotasoa, sekä EVM:ää. Työkalu tuottaa tulokset visuaalisena ja tekstipohjaisena, jotta analyysia voidaan tehdä niin manuaalisessa kuin automaattisessa testauksessa. Työkalun käyttöönotto on tehostanut UL suunnan dataputken testausta radio-integrointitiimeissä, tarjoten datan laatua kuvaavaa metriikkaa sekä mahdollistaen testauksen automatisoinnin