The demand for mobile wireless network resources is constantly on the rise, pushing for new communication technologies that are able to support unprecedented rates. In this thesis we address the issue by considering advanced interference management techniques to exploit the available resources more efficiently under relaxed channel state information (CSI) assumptions. While the initial studies focus on current half-duplex (HD) technology, we then move on to full-duplex (FD) communication due to its inherent potential to improve spectral efficiency. Work in this thesis is divided into four main parts as follows. In the first part, we focus on the two-cell two-user-per-cell interference broadcast channel (IBC) and consider the use of topological interference management (TIM) to manage inter-cell interference in an alternating connectivity scenario. Within this context we derive novel outer bounds on the achievable degrees of freedom (DoF) for different system configurations, namely, single-input single-output (SISO), multiple-input single-output (MISO) and multiple-input multiple-output (MIMO) systems. Additionally, we propose new transmission schemes based on joint coding across states that exploit global topological information at the transmitter to increase achievable DoF. Results show that when a single state has a probability of occurrence equal to one, the derived bounds are tight with up to a twofold increase in achievable DoF for the best case scenario. Additionally, when all alternating connectivity states are equiprobable: the SISO system gains 11/16 DoF, achieving 96:4% of the derived outer bound; while the MISO/MIMO scenario has a gain of 1/2 DoF, achieving the outer bound itself. In the second part, we consider a general G-cell K-user-per-cell MIMO IBC and analyse the performance of linear interference alignment (IA) under imperfect CSI. Having imperfect channel knowledge impacts the effectiveness of the IA beamformers, and leads to a significant amount of residual leakage interference. Understanding the extent of this impact is a fundamental step towards obtaining a performance characterisation that is more relevant to practical scenarios. The CSI error model used is highly versatile, allowing the error to be treated either as a function of the signal-to-noise ratio (SNR) or as independent of it. Based on this error model, we derive a novel upper bound on the asymptotic mean sum rate loss and quantify the DoF loss due to imperfect CSI. Furthermore, we propose a new version of the maximum signal-to-interference plus noise ratio (Max-SINR) algorithm which takes into account statistical knowledge of the CSI error in order to improve performance over the naive counterpart in the presence of CSI mismatch. In the third part, we shift our attention to FD systems and consider weighted sum rate (WSR) maximisation for multi-user multi-cell networks where FD base-stations (BSs) communicate with HD downlink (DL) and uplink (UL) users. Since WSR problems are non-convex we transform them into weighted minimum mean squared error (WMMSE) ones that are proven to converge. Our analysis is first carried out for perfect CSI and then expanded to cater for imperfect CSI under two types of error models, namely, a norm-bounded error model and a stochastic error model. Additionally, we propose an algorithm that maximises the total DL rate subject to each UL user achieving a desired target rate. Results show that the use of FD BSs provides significant gains in achievable rate over the use of HD BSs, with a gain of 1:92 for the best case scenario under perfect CSI. They also demonstrate the robust performance of the imperfect CSI designs, and confirm that FD outperforms HD even under CSI mismatch conditions. Finally, the fourth part considers the use of linear IA to manage interference in a multi-user multi-cell network with FD BSs and HD users under imperfect CSI. The number of interference links present in such a system is considerably greater than that present in the HD network counterpart; thus, understanding the impact of residual leakage interference on performance is even more important for FD enabled networks. Using the same generalised CSI error model from the second part, we study the performance of IA by characterising the sum rate and DoF losses incurred due to imperfect CSI. Additionally, we propose two novel IA algorithms applicable to this network; the first one is based on minimising the mean squared error (MMSE), while the second is based on Max-SINR. The proposed algorithms exploit statistical knowledge of the CSI error variance in order to improve performance. Moreover, they are shown to be equivalent under certain conditions, even though the MMSE based one has lower computational complexity. Furthermore for the multi-cell case, we also derive the proper condition for IA feasibility.

Titel: Corporate Social Irresponsibility och Finansiell Prestation - En kvantitativ studie om relationen mellan Corporate Social Irresponsibility och finansiell prestation   Nivå: Examensarbete på Grundnivå (kandidatexamen) i ämnet företagsekonomi   Författare: Malin Månsberg   Handledare: Catherine Lions   Datum: 2018 – maj   Syfte: Många forskare har undersökt hur företags sociala ansvarstagande (CSR) påverkar den finansiella prestationen (FP). Denna studie riktar istället fokus på den negativa motsvarigheten, Corporate Social Irresponsibility (CSI), som länge varit i skuggan av de positiva effekter som CSR påstås ha på företagens lönsamhet. Studiens syfte är att undersöka om socialt oansvariga handlingar påverkar företags finansiella prestation, ur både intressentteorin och den neoklassiska teorins perspektiv. Frågeställningar som tas upp är: Är det viktigt att undvika kontroverser? Får CSI ekonomiska konsekvenser? I så fall, vilka?   Metod: Som följd av en positivistisk tradition har en hypotetisk-deduktiv ansats med kvantitativ metod baserat på sekundärdata och en tvärsnittsdesign använts för att undersöka sambandet mellan CSI och FP. Hypotesen prövas genom multivariatanalys och förväntas kunna besvara frågan om det existerar ett samband och om så, vilken riktning sambandet har.   Resultat & slutsats: Resultatet bekräftar att CSI leder till en högre finansiell prestation. Således gynnas företag som är inblandade i kontroverser på ett ekonomiskt plan. Resultatet indikerar att den neoklassiska teorin är mer användbar för att förklara relationen än vad intressentteorin är. Av det kan slutsatsen dras att omgivningen inte är benägen att ”straffa” företag som beter sig illa, eftersom resultatet indikerar att CSI leder till en högre finansiell prestation.   Examensarbetets bidrag: Resultatet utmanar den rådande trenden att undersöka CSI utifrån intressentteorin. Den positiva korrelationen bekräftar även att CSI är ett eget fenomen vars effekter inte är analoga med CSR, vilket vidgar den tidigare forskningen om socialt ansvar.   Förslag till fortsatt forskning: Studien begränsning finns främst i att CSI ofta hålls dolt. Effekten av CSI som inte uppmärksammas i media kan därför ha en annan relation till FP.   Nyckelord: Corporate Social Irresponsibility (CSI), Financial Performance (FP), Intressentteorin, Neoklassisk teori

Ericsson Brasil / The International Telecommunications Union (ITU) established through the International Mobile Telecommunications (IMT)-Advanced a set of requirements for high performance of 4th Generation (4G) communication systems and, with the aim of meeting such requirements, 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is considering a set of enhancements, referred to as LTE-Advanced. In the LTE-Advanced context, Coordinated Multi-Point (CoMP) communication appears as a promising technology to boost system throughput and to allow for an efficient Radio Resource Allocation (RRA). CoMP systems promise very high performance in terms of spectral efficiency and coverage benefits when perfect Channel State Information (CSI) is available at the transmitter. However, perfect CSI is difficult to obtain in CoMP systems due to an increased number of channel parameters to be estimated at the receiver and to be fed back to the transmitter. So, the performance of such systems is compromised when the CSI is not perfectly known during CoMP processing, which is an important problem to be addressed. Space Division Multiple Access (SDMA) grouping algorithms are usually employed in order to find a suitable set of users for spatial multiplexing. The largest SDMA group is not always the best group in a given data transmission such that higher gains might be achieved by dynamically adjusting the SDMA group size. Besides, algorithms that balance the Signal to Interference-plus-Noise Ratio (SINR) among different links might ensure a certain level of link quality and so provide a more reliable communication for the scheduled users. This master thesis provides system-level analyses for RRA algorithms that exploit coordination in the downlink of CoMP systems to implement adaptive resource reuse and so improve system throughput. Herein, RRA strategies which consider dynamic SDMA grouping, joint precoding and power allocation for SINR balancing are studied in CoMP systems assuming imperfect CSI in order to obtain a better approximation with regard to the real-world implementations. It is shown through system-level analyses that quite high throughput gains are achieved through intelligent RRA. In conclusion, the results show that Sequential Removal Algorithms (SRAs) and SINR balancing provide system spectral efficiency gains. However, a critical degradation on the performance of these RRA strategies due to imperfect CSI is also shown. / A UniÃo Internacional para TelecomunicaÃÃes (ITU) estabeleceu atravÃs da iniciativa para o Sistema AvanÃado Internacional de TelecomunicaÃÃes MÃveis (IMT-Advanced), um conjunto de requisitos de alto desempenho para os sistemas de comunicaÃÃo de quarta geraÃÃo (4G) e, com o objetivo de atender tais requisitos, a EvoluÃÃo de Longo Prazo (LTE) do Projeto de Parceria para a Terceira GeraÃÃo (3GPP) està considerando um conjunto de melhorias, referidas como LTE-AvanÃado. No contexto do LTE-AvanÃado, a comunicaÃÃo multi-ponto coordenada (CoMP) aparece como uma tecnologia promissora para aumentar a vazÃo do sistema e permitir uma AlocaÃÃo de Recursos de RÃdio (RRA) eficiente. Os sistemas CoMP prometem alto desempenho em termos de eficiÃncia espectral e benefÃcios de cobertura quando a InformaÃÃo do Estado do Canal (CSI) perfeita està disponÃvel no transmissor. No entanto, CSI perfeita à difÃcil de se obter em sistemas CoMP devido a um alto nÃmero de parÃmetros de canal a serem estimados no receptor e enviados para o transmissor. Assim, o desempenho de tais sistemas à comprometido quando a CSI nÃo à perfeitamente conhecida durante o processamento CoMP tal que esse à um problema importante a ser abordado. Algoritmos de agrupamento para MÃltiplo Acesso por DivisÃo no EspaÃo (SDMA) geralmente sÃo utilizados a fim de encontrar um conjunto adequado de usuÃrios para multiplexaÃÃo espacial. O maior grupo SDMA nem sempre à o melhor grupo em uma transmissÃo de dados tal que maiores ganhos podem ser obtidos ajustando dinamicamente o tamanho do grupo SDMA. AlÃm disso, os algoritmos que balanceiam a RazÃo Sinal-InterferÃncia mais RuÃdo (SINR) entre diferentes canais podem garantir um certo nÃvel de qualidade de canal e assim proporcionar uma comunicaÃÃo mais confiÃvel para os usuÃrios agrupados. Esta dissertaÃÃo de mestrado fornece anÃlises em nÃvel sistÃmico para algoritmos de RRA que exploram a coordenaÃÃo no enlace direto de sistemas CoMP para implementar reuso adaptativo de recursos e assim melhorar o desempenho do sistema. SÃo estudadas aqui estratÃgias de RRA em sistemas CoMP que consideram agrupamento SDMA dinÃmico, precodificaÃÃo e alocaÃÃo de potÃncia conjuntas para balanceamento de SINR, sendo assumida CSI imperfeita a fim de conseguir maior aproximaÃÃo com relaÃÃo Ãs implementaÃÃs em cenÃrios reais. à mostrado atravÃs de anÃlises em nÃvel sistÃmico que ganhos de vazÃo bastante altos sÃo alcanÃados atravÃs de RRA inteligente. Em conclusÃo, os resultados mostram que Algoritmos de RemoÃÃo Sequencial (SRAs) e de balanceamento de SINR proporcionam ganhos de eficiÃncia espectral do sistema. No entanto, à tambÃm mostrada uma degradaÃÃo crÃtica no desempenho dessas estratÃgias de RRA devido à CSI imperfeita.

Millimeter wave (mmWave) spectrum above 30 GHz offers us an opportunity to pursue high-data-rate transmission using a channel bandwidth up to several gigahertz. To provide reliable link quality in mmWave frequency bands, hybrid analog-digital beamforming plays a crucial role in overcoming severe path loss and, meanwhile, satisfies the demand for low-power-consumption radio frequency (RF) devices. Implementing hybrid beamforming based on available channel state information (CSI) is a common solution in the hybrid beamforming literature. However, many reference methods underestimate the computational complexity of channel estimation for large antenna arrays or subsequent steps, such as the singular value decomposition of a channel matrix. To this end, we present a low-complexity scheme that exploits implicit channel knowledge to facilitate the design of hybrid beamforming for frequency-selective fading channels. We start from the study of channel estimation using the orthogonal matching pursuit (OMP) algorithm and realize that the problems of channel estimation and analog beam selection are equivalent if the candidates for analog beamforming vectors in the codebooks are mutually orthogonal. This implies that when orthogonal codebooks are employed, the observations used in channel estimation for large antenna arrays can be used to implement hybrid beamforming directly. The above-mentioned observations can be regarded as \textbf{implicit CSI}; they are coupling coefficients of all possible pairs of analog beamforming vectors on both sides of the channel. The idea of using implicit CSI to implement hybrid beamforming is further extended to the cases of non-orthogonal codebooks. Instead of calculating the mutual information between the transmitter and receiver, we focus on small-size coupling matrices between beam patterns selected by using appropriate key parameters as performance indicators. Therefore, the proposed hybrid beamforming method becomes much simpler: it amounts to collecting different sets of large-power coupling coefficients to construct multiple alternatives to an effective channel matrix. Then, the set yielding the largest Frobenius norm (or the largest absolute value of the determinant) of the effective channel provides the solution to the hybrid beamforming problem. The proposed hybrid beamforming approach clearly shows that the performance of hybrid beamforming is dominated by the quality of the coupling coefficients. Considering a fixed-length training sequence, we exploit mmWave channels' sparsity shown in the delay and angular domains to refine the quality of the coupling coefficients as well as to improve the hybrid beamforming performance.

The demand for accurate localization under indoor environments has increased dramatically in recent years. To be cost-effective, most of the localization solutions are based on the WiFi signals, utilizing the pervasive deployment of WiFi infrastructure and availability of the WiFi enabled mobile devices. In this thesis, we develop completed indoor localization solutions based on WiFi fingerprinting and machine learning approaches with two types of WiFi fingerprints including received signal strength indicator (RSSI) and channel state information (CSI). Starting from the low complexity algorithm, we propose a soft range limited K nearest neighbours (SRL-KNN) to address spatial ambiguity and the fluctuation of WiFi signals. SRL-KNN exploits RSSI and scales the fingerprint distance by a range factor related to the physical distance between the user’s previous position and the reference location in the database. Although utilizing the prior locations, SRL-KNN does not require knowledge of the exact moving speed and direction of the user. Besides, the idea of the soft range limiting factor can be applied to all of the existed probabilistic methods, i.e., parametric and nonparametric methods, to improve their performances. A semi-sequential short term memory step is proposed to add to the existed probabilistic methods to reduce their spatial ambiguity of fingerprints and boost significantly their localization accuracy. In the following research phase, instead of locating user's position one at a time as in the cases of conventional algorithms, our recurrent neuron networks (RNNs) solution aims at trajectory positioning and takes into account of the relation among RSSI measurements in a trajectory. The results using different types of RNN including vanilla RNN, long short-term memory (LSTM), gated recurrent unit (GRU) and bidirectional LSTM (BiLSTM) are presented. Next, the problem of localization using only one single router is analysed. CSI information will be adopted along with RSSI to enhance the localization accuracy. Each of the reference point (RP) is presented by a group of CSI measurements from several WiFi subcarriers which we call CSI images. The combination of convolutional neural network (CNN) and LSTM model is proposed. CNN extracts the useful information from several CSI values (CSI images), and then LSTM will exploit this information in sequential timesteps to determine the user's location. Finally, a fully practical passive indoor localization is proposed. Most of the conventional methods rely on the collected WiFi signal on the mobile devices (active information), which requires a dedicated software to be installed. Different from them, we leverage the received data of the routers (passive information) to locate the position of the user. The localization accuracy is investigated through experiments with several phones, e.g., Nexus 5, Samsung, Iphone and HTC, in hundreds of testing locations. The experimental results demonstrate that our proposed localization scheme achieves an average localization error of around 1.5 m when the phone is in idle mode, and approximately 1 m when it actively transmits data. / Graduate

This diploma thesis examines the possibilities of using the PE ratio in the creation of a stock portfolio on the Chinese and American stock market. The result of this work is the finding that low PE shares achieve higher risk-weighted returns over short and long investment horizons than shares with high PE values in both ex-amined markets. However, based on the detected volatility of the shares with the extreme values of PE, it is possible to recommend the use of this indicator for creation of the portfolio only to the most speculative investors.

Nowadays, financial derivatives play an increasingly important role in the global financial system, and options are popular structural financial derivatives, which attract much attention from academia and the industry. China Financial Futures Exchange (CFFEX) initiated the CSI 1000 index future and CSI 1000 index option in the Chinese market on July 22, 2022, which indicates a trend of acceleration in financial innovations in China’s financial market. This dissertation focuses on the volatility models in option pricing and modern numerical procedures that approximate option prices. In this dissertation, different stochastic volatility models, for example, the Black–Scholes model and the Heston stochastic volatility model, are introduced and applied to price in not only European options but also exotic options, which possess complicated payoff structures. Moreover, a comprehensive empirical analysis is conducted to demonstrate these option pricing algorithms based on the recent data of CSI 1000 index options in the Chinese market. / Business Administration/Finance

Background: The increase in public awareness and rising social expectations have changed the role businesses have in modern society, as they are expected to deliver both organizational and social value. Despite this, most social engagements have previously been philanthropic, which is argued to only scratch the surface of societal issues. The concept of CSI was therefore coined, and it focuses on leveraging companies’ core capabilities to be innovative while forming collaborations and partnerships between units within the company and external organizations to mend social ills. This concept has been described to yield excellent outcomes; however, the initiation and implementation of CSI have been vaguely depicted in literature.  Purpose: Previous research of CSI has centralized around the outcomes, such as innovation capabilities and competitive advantage, and regularly compared them to more basic philanthropic initiatives. Therefore, the purpose of this research is to focus on the origin of CSI in organizations and how partnerships can facilitate its generation. The thesis further intends to collect and summarize the various definitions of CSI to establish the occurrence of CSI in various organizations.  Method: This research adopted a critical realism philosophical stance to perform a multiple case study. We did this with a qualitative research design, including eight semi-structured interviews with participants from different organizations currently engaged in partnerships. The data were analyzed using thematic analysis, which we practically performed using an abductive approach to code data and the subsequent thematization. The findings of this thesis are then, using theory matching and triangulation, presented to discover alternative explanations for the facilitating factors of CSI in partnerships.  Conclusion: We consolidated previous research to construct a definition of CSI. This consolidated concept was used to evaluate the initiatives in the participants’ partnerships. We used thematic analysis to define three distinct facilitating themes for generating CSI in partnerships: People, Partnership Conditions, and Institutional Entity Structure. Conclusively, the purpose was achieved as our findings and subsequent analysis indicates that the three realized themes substantially influence CSI generation. It was found that these facilitating factors are interdependent, as the underdevelopment of one area negatively influenced the ability to engage in CSI.

In the domain of CAD/CAM, innovative strategies are devised and positioned to transform communication and streamline machining processes. Recent advancements have fueled the need for tailored solutions integrated into CAM software, having a transformative impact in this field. To address this, Sandvik Coromant is currently developing digital machining solutions to improve the standard of manufacturing data by extending their development in different CAM systems. This thesis project delves into enhancing efficiency in tool path generation utilizing the extensive knowledge cultivated by CoroPlus® Tool Path, a cloud-based specialized tool path solution. It focuses on integrating CoroPlus® Tool Path as a Plug-in within Siemens NX and Mastercam, simplifying complex setups, enabling users to create precise tool motion with ease. The project explores the vital role of APIs in seamless CAM interactions while presenting a feasible data management framework between the components involved. A program was developed to perform the stated functions through a generic plug-in coined CSI (CAM System Integration). A data flow architecture has been designed such that for each node, there exists a structured data transfer mechanism that facilitates data communication in the plug-in/solution. The possibility of utilizing a STEP file for this data transfer is also discussed. In this project, the results of the framework implementation, as well as its challenges and limitations, were discussed in order to improve the existing integration solution. / Inom CAD/CAM-området utvecklas och positioneras innovativa strategier för att omvandla kommunikation och strömlinjeforma bearbetningsprocesser. Nyliga framsteg har drivit behovet av skräddarsydda lösningar integrerade i CAM-programvara, med en transformerande effekt inom detta område. För att möta detta utvecklar Sandvik Coromant för närvarande digitala bearbetningslösningar för att förbättra standarden för tillverkningsdata genom att utöka deras utveckling i olika CAM-system. Det här examensprojektet fokuserar på att förbättra effektiviteten i verktygsbana genom att använda den omfattande kunskap som odlas av CoroPlus® Tool Path, en molnbaserad specialiserad verktygsbanelösning. Projektet fokuserar på att integrera CoroPlus® Tool Path som en Plug-in inom Siemens NX och Mastercam för att förenkla komplexa inställningar och möjliggöra användare att skapa exakta verktygsrörelser med lätthet. Projektet utforskar den avgörande rollen som API:er spelar i sömlösa CAM-interaktioner samtidigt som det presenterar en genomförbar ram för datahantering mellan de involverade komponenterna. Ett program utvecklades för att utföra de angivna funktionerna genom en generisk plug-in kallad CSI (CAM System Integration). En dataflödesarkitektur har utformats så att det för varje nod finns en strukturerad datatransfermekanism som underlättar datakommunikationen i plug-in/lösningen. Möjligheten att använda STEP-fil för denna datatransfer diskuteras också. I detta projekt diskuterades resultaten av ramverksimplementeringen samt dess utmaningar och begränsningar för att förbättra den befintliga integrationslösningen.

Television shows, in particular CSI: Crime Scene Investigation, have captured the attention of the majority of Americans. As a consequence of these shows, the "CSI effect" has evolved. The CSI effect primarily occurs when people watch crime or law related shows resulting in them gaining an unrealistic expectation of what they think should occur in real trials. This is a concern for prospective jurors who take part in criminal trials. This thesis will reveal how the CSI effect has swept the nation. A large part of this study will be devoted to illustrating how the CSI effect has had an impact on jurors, criminals and the American court system. This thesis will shed light on how television has the power to alter a juror's mind, even if it is a decision that could completely change the defendant's life. This thesis will also examine how legal professionals have strategically begun to mention the CSI effect during their trials in court. Nowadays, it is an ordinary procedure for attorneys, during voir dire, to question prospective jurors about their television viewing habits, as it pertains to CSI. This study will also examine how the producers of CSI discount the effect in its entirety. The creators believe that their creation has been a helpful milestone in the evolution of our criminal justice system.