This dissertation presents methods for modeling and mitigating voltage noise and timing jitter across high-speed chip-to-chip interconnects. Channel equalization and associated tuning schemes have been developed to target the distinct characteristics and signal degradation exhibited in the clock and data signals of multi-Gigabit/second digital communication links. Multiple methods for generating realistically degraded signals for the purpose of simulation are also presented and used to verify the proposed equalization and filtering topologies. Specifically, a new technique for modeling high-speed jittery clocks in the frequency domain is presented and shown to reduce transient simulation time and memory requirements, while simultaneously improving the timing resolution and accuracy of the simulation by minimizing the dependence on the transient simulation time-step. The technique is further developed to provide unprecedented control over the timing characteristics of the generated signals, and is then extended to the generation of random data signals with definable jitter statistics. Through these techniques,realistic clock and data waveforms are constructible, providing for the visualization of the combined effects of voltage and timing degradation, while at the same time tracking the phase relationship between the clock and data signals as they pass across their respective channels and through the receiving circuitry of the communication link. New methods for the automated tuning of second-order continuous-time channel equalizers are proposed based on the simulated or measured single pulse and double pulse responses of the transmission channel. Using only one degree of freedom, the methods target the reduction of inter-symbol interference (ISI) as identified in the single and double pulses. Through tuning either the circuit quality factor (Q), the peaking frequency, or the frequency zero, the methods are shown to adapt to a variety of channel lengths and datarates from the same original equalizer transfer function, implying a good degree of generality, while offering a simple, yet effective, method for ISI reduction. Finally, the design of an active 5 Gigahertz (GHz) bandpass filter, employed for high-speed clock conditioning, is presented and shown to address both random and deterministic components of the clock signal degradation. The bandpass transfer function is achieved through a combination of AC coupling and a resonant LC tank consisting of on-chip interleaved spiral inductors and a tunable capacitor array. Through adjusting the load capacitance in parallel with the inductors, the center frequency of the filter is tunable over a range of nearly 5GHz. The design targets a supply voltage of 1.2 volts and draws approximately 5.7 milliamps of current.

When the covid-19 pandemic started, managers were only able to lead their employees through digital communication. During the subsequent telework a completely new research area, in need of new knowledge, was created. The purpose of this study is to gain an understanding of opportunities and challenges of remote leadership, experienced by managers. This at a time of only digital communication with employees, with no physical meetings or interactions. The study will answer the following two issues, “What factors are important for managers to take into account when applying a leadership style to teleworking employees?” and “Which internal communication functions in the organization have worked better or not according to managers, when remotely managing employees?”. This exploratory study has its theoretical starting point in situational theory, as well as in Richmond, McCroskey and Powell’s six functions in organizational communication. Through semi-structured interviews, empirical data has been collected and then analyzed through coding, thematization and summation. The result of this study indicates that future managers, conducting digital leadership, will need to take each employee's needs and personal situation into account. Managers need to adopt a functioning leadership style, while keeping important factors regarding employees in mind. This in order to successfully lead each teleworking employee through digital communication.

Att “sexta” innebär att med textbaserade digitala medier kommunicera med sexuella partners, vilket är en praktik som kan upplevas väldigt intim trots mediets begränsningar av de karaktäristiska dragen av en fysisk interaktion. Denna studie har som syfte att ge en övergripande bild över hur denna typ av interaktion konstrueras och tar sig uttryck, vilket görs i en tredelad undersökning som fokuserar på kommunikationsmönsterna och hur dessa reflekteras över. Det empiriska materialet utgörs av 18 bidrag insamlade via en nätbaserad deltagande observation, 2 kvalitativa intervjuer och 56 svarande på en nätbaserad enkät. Genom ett självselektivt urval avgränsades den studerade gruppen till i huvudsak informanter med en medianålder på 27 år med erfarenheter av heterosexuella relationer. Det studien visar är att den distansering och begränsning denna kommunikation innebär oftast möjliggör förmågan hos informanterna att uttrycka sig friare än i en interaktion ansikte mot ansikte. Samtidigt värderas ändå den fysiska interaktionen högre då denna är mer “på riktigt”. Med begreppet digital sexuell kommunikation (DSK) har vi också ämnat klargöra och definiera det forskningsområde som denna studie genomförts inom, vilket kombinerar medie- och kommunikationsvetenskap med det sexualpsykologiska fältet. / “Sexting” is the communication between sexual partners through textbased digital media, which is a practice that can be experienced as very intimate despite the mediums limitations of the characteristics of a physical interaction. The purpose of this study is to offer a comprehensive overview of how this type of interaction is constructed and expressed, which has been conducted through a three-parted examination of the specifics of these communication patterns and how they are reflected upon. The empirical data consists of 18 contributions collected through a netbased participatory observation, 2 qualitative interviews and 56 respondents of a netbased survey. Through a method of selfselection the informant group was generated and constricted to mainly informants of an average age of 27 with experiences of heterosexual relations. What the study concludes is that the distance and limitation of this type of communication often contributes to a sense of a more liberated way of expression than what is possible in a face-to-face interaction. Yet the informants value the physical type of interaction higher as this is seen as more “real”. With the term digital sexual communication (DSC) we also aim to clarify and define the research area in which we conduct this study, which combines the science of media & communication with the field of sexual psychology.

The study explored how the use of Emojis – beyond being used just as playful joke markers and tone-setters – shape culture and identity within a community of practice. Through the means of two qualitative Focus Group interviews involving ten members from a local soccer team, the purpose was to examine in-depth participants’ motivations for using Emojis, and their feelings about the Emojis that they receive both within and outside their community. Results showed that Emojis – irrespective of shape – are understood as signs representing an individual’s inner positive energy and good will; when such signs are used regularly within a community, this contributes to that the community culture emerge as positive and friendly. Expanding on these findings, results also illustrated that Emojis are perceived as symbols of likeness towards the group and that they contribute to the shaping of open and permissive culture in which emotions are allowed to flow freely – an effect which seem to be transferred to their offline environment too. Drawing from theories of Cultural Psychology and Cultural Semiotics, the thesis presents an innovative view of Emojis as both products as well as producers of culture; products because they are graphic representations of emotions which become meaningful cultural signs when posted online, and producers because they affect members’ perception of reality within the community of practice. The thesis also conclude that the use of Emojis is closely linked to personality and identity; as identities are continuously shaped through the symbolic association of Emojis, this affect not only how members of a community perceive the individuals using them, but also how we perceive the community in which these identities circulate and operate. This finding paved the way for interesting future studies on personal identity building through Emoji use.

År 2009 upphörde apoteksmonpolet i Sverige och Apoteket AB blev därmed mer konkurrensutsatt än någonsin. Det resulterade även i att deras behov av att särskilja sig från de nystartade kedjorna och butikerna ökade rejält och därför fick företagets varumärke, kommunikationsstrategier och val av kommunikationskanaler mycket stor betydelse. Syftet med denna studie har varit att undersöka hur Apoteket AB arbetar med visuell och digital kommunikation i butik och på webben för att stärka kundens uppfattning om företaget och varumärket. Studien ämnar även att undersöka hur Apoteket AB’s konsumenter upplever och påverkas av deras kommunikation samt om det finns mönster och möjliga strategier mellan val av mediekanaler och framgångsfaktorer hos Apoteket AB.För att besvara frågeställningarna genomfördes en kvalitativ studie som bestod av intervjuer med utvalda personer inom Apoteket AB som har god kunskap inom områdena visuell och digital kommunikation både i butik och på webben. För att få in ett konsumentperspektiv i studien genomfördes även en fokusgrupp med fem utvalda kunder som regelbundet handlar på Apoteket AB. Det empiriska materialet diskuterades och analyserades sedan tillsammans med den litteraturstudie som gjordes för att följa upp syftet och ge svar på studiens problemformulering.Studiens resultat visade att Apoteket AB arbetar mycket med differentierad marknadsföring utifrån utvalda kundsegment, vilket har visat sig vara en mycket framgångsrik strategi. Ytterligare en viktig del i deras kommunikationsstrategi har varit att vara synliga och tillgängliga på de flesta plattformar där deras kunder befinner sig. Eftersom Apoteket AB’s kundkrets sträcker sig över många generationer har de därför valt att både använda sig av traditionella och digitala medier. Denna mediemix fungerar för Apoteket AB då kommunikationen når ut till de utvalda kundsegmenten och utifrån det empiriska resultatet framkom det även att respondenterna upplever kommunikationen som intressant, trovärdig och transparent. Men det som framförallt har fått respondenterna att känna igen Apoteket AB’s varumärke och dess produkter har varit enhetligheten i deras kommunikation. Apoteket AB har en tydlig grafisk identitet med utvalda typsnitt, färger och former som genomsyrar all deras kommunikation och allt deras marknadsmaterial. Detta har visat sig vara den största anledningen till att konsumentupplevelsen har stärkts både i butik och på webben. / The Swedish pharmacy market was deregulated in 2009 after a state-run monopoly of 40 years. This meant that Apoteket AB had to adapt both its business and market share to the new pharmacy market. The market competition increased Apoteket AB’s need to differentiate themselves from the other chains and pharmacies and therefore the company's brand, communications strategies and choice of communication channels became very important.The purpose of this study has been to examine how Apoteket AB works with visual and digital communication both in stores and on the Web to enhance the customer's perception of the company, the brand and the store. The study also intends to explore how Apoteket AB’s consumers perceive and are affected by their communication, and if there are patterns and possible strategies between the choice of media channels and success factors of Apoteket AB.To answer these questions a qualitative study was conducted, consisting of interviews with selected individuals within Apoteket AB who have good knowledge in the areas of visual and digital communication both in stores and online. A focusgroup was conducted to get the consumer perspective in to the study. It consisted of five selected customers who regularly purchased at Apoteket AB. The empirical material was later discussed and analyzed together with the literature study that had been performed to answer the purpose of the study.The results showed that Apoteket AB works extensively with differentiated marketing, based on selected customer segments. This has proven to be a very successful strategy. Another important part of their communication strategy has been to be visible and accessible on most platforms where their customers are present. Since Apoteket AB’s customer base spans many generations, they have chosen to use both traditional and digital media. This media mix works well for Apoteket AB because their communication reaches out to the selected customer segments. The empirical results also revealed that the consumer perceive Apoteket AB’s communication as interesting, credible and transparent. The most important reason that the respondents recognize the Apoteket AB brand and its products is the consistency in their communications. Apoteket AB has a distinct visual identity with selected fonts, colors and shapes that permeates all their communication and their marketing materials. This has proven to be the major reason that the consumer experience has been strengthened, both in stores and on the web.

<p> This thesis addresses the design of fractionally-spaced equalizers for a digital communication system which is susceptible to Adjacent Channel Interference (ACI). ACI can render an otherwise well designed system prone to excess bit errors. Algorithms for a trained adaptive FIR linear fractionally-spaced equalizer (FSE) with explicit sidelobe control are developed in order to provide robustness to ACI. The explicit sidelobe control is achieved by imposing a quadratic inequality constraint on the frequency response of the equalizer at a discrete set of frequency points in the sidelobe region.</p> <p> Algorithms are developed for both block adaptive and symbol-by-symbol adaptive modes. These algorithms use interior point optimization techniques to find the optimal equalizer coefficients. In the block adaptive mode, the problem is reformulated as a Second Order Cone Program (SOCP). In the symbol-by-symbol adaptive mode, the philosophy of the barrier approach to interior point methods is adopted. The concept of a central path and the Method of Analytic Centers (MAC) are used to develop two practically implementable algorithms, namely IPM2 and SBM, for performing symbol-by-symbol adaptive, fractionally-spaced equalization, with multiple quadratic inequality constraints.</p> <p> The performance of the proposed algorithms is compared to that of the Wiener filter, and the standard RLS algorithm with explicit diagonal loading. In the computer simulations, the proposed algorithms perform better in the sense that they provide the desired robustness when the communication model is prone to intermittent interferers in the sidelobe region of the frequency response of the FSE. Although the proposed algorithms have a moderately higher computational cost, their insensitivity to the deleterious effects of ACI make them an attractive choice in certain applications.</p> / Thesis / Master of Applied Science (MASc)

No / Multi-antenna(MIMO) techniques are reported to improve the performance of radio communication systems in terms of their capacity and spectral efficiency. In combination with appropriate receiver technologies they can also provide savings in the required transmit power with respect to target bit error rate. Long Term Evolution(LTE), one of the candidates for fourth generation(4G) mobile communication systems has MIMO as one of its underlying technologies and ITU defined channel models for its propagating environment. This paper undertakes a comprehensive verification of the performance of transmit diversity MIMO in the downlink sector of LTE. It uses models built using MATLAB to carry out simulations. It is deduced that generally increasing transmit diversity configuration from 2x2 to 4x4 offers SNR savings in flat fading channels though with a user equipment moving at 30km/hr, deploying 2x2 offers higher SNR saving below 7dB. Furthermore bandwidth variation has minimal effect on the BER performance of transmit MIMO except at SNR values above 9dB while the gains of higher modulation schemes come with a transmit power penalty.

Proliferation of new wireless technologies has rekindled the interest on the design, analysis and implementation of suboptimal receiver structures that provide good error probability performance with reduced power consumption and complexity particularly when the order of diversity is large. This thesis presents a unified analytical framework to perform a trade-off study for a class of hybrid generalized selection combining technique for ultra-wideband, spread-spectrum and millimeter-wave communication receiver designs. The thesis also develops an exact mathematical framework to analyze the performance of a dual-diversity equal gain combining (EGC) receiver in correlated Nakagami-m channels, which had defied a simple solution in the past. The framework facilitates efficient evaluation of the mean and variance of coherent EGC output signal-to-noise ratio, outage probability and average symbol error probability for a broad range of digital modulation schemes. A comprehensive study of various dual-diversity techniques with non-independent and non-identical fading statistics is also presented. Finally, the thesis develops some closed-form solutions for a few integrals involving the generalized Marcum Q-function. Integrals of these types often arise in the analysis of multichannel diversity reception of differentially coherent and noncoherent digital communications over Nakagami-m channels. Several other applications are also discussed. / Master of Science

Instant Messaging är en digital kommunikationskanal i ett användarvänligt format för kommunikation i nära realtid. Som en växande trend på arbetsplatsen väljer allt fler företag att integrera kommunikationskanalen i sina kommunikationslösningar. Samtidigt följer användningen av Instant Messaging med en omedveten andrahands-effekt, något som lämnat synliga avtryck på företagens kommunikationsmönster. Kommunikationsteoretikerna Turner och Reinsch (2007) förklarar förekommandet genom att introducera termen multikommunikation, hur anställda identifieras gå från att ha sekventiella till simultana interaktioner. En användning som formats efter Instant Messagings avsaknad av icke-verbala indikationer i att kräva mindre koordinering och möjliggöra för anställda att fördela sin uppmärksamhet över flera interaktioner. Turner och Reinsch (2007) föreslår därför att multikommunikation är att föredra när företag värderar inre effektivitet eftersom anställda som deltar i simultana interaktioner kan överprestera övriga. Andra insatta teoretiker har istället identifierat hur avsaknaden av icke-verbala indikationer ger kommunikationssvårigheter i form av funktionsbegränsningar och intensiva kommunikationsflöden. Något som ger implikationer för anställdas arbetsproduktivitet i att Instant Messaging kan vara avbrytande, försvåra en samordnad turtagning och göra det ansträngande att förmedla känslor. Uppsatsen syftar därför till att undersöka hur anställda hanterar den multikommunikation och de kommunikativa svårigheter som uppstår i samband med användandet av Instant Messaging. Genom deltagande observationer och semi-strukturerade intervjuer, på en avdelning inom ett multinationellt industriföretag, utförs en fallstudie. Resultat visar att sättet anställda hanterar Instant Messaging är starkt bundet till den kontext kommunikationskanalen nyttjas i. I en sammansättning av erfarenheter och sociala regler identifieras överenskomna strategier vilka balanserar och kontrollerar kommunikationsflödet, samt får funktionsbegränsningar att ge en minskad negativ effekt. Genom att prioritera kommunicerat innehåll efter tidskänslighet minskar antalet interaktioner, får kollegor att inte avbrytas i onödan och underlättar till en korrekt fördelning av uppmärksamhet. Samtidigt skickas främst skärmbilder tagna i affärssystemet SAP vilka inrymmer information i ett formaliserat gränssnitt. Något som gör kommunikationsflödet mindre intensivt i att kunna ersätta otroligt många meddelanden. Det underlättar till en samordnad turtagning, snabbare responstid och mindre ansträngning i att anställda inte skriftligt formulerar information med tillhörande känslor. / Instant Messaging is a digital communication channel with a user-friendly design for near realtime communication. As a growing trend in the workplace, more and more companies decide to integrate the communication channel into their communication solutions. The use of Instant Messaging follows with a secondary effect revealed in visible marks on corporate communication patterns. Communication theorists Turner and Reinsch (2007) explains the occurrence by introducing the term Multicommunication, how employees are going from having sequential to simultaneous interactions. A use shaped by Instant Messaging's lack of non-verbal indications in allowing for less coordination and an allocation of attention across multiple interactions. Turner and Reinsch (2007) therefore propose that multicommunication is preferable to companies seeking efficiency seeing that employees participating in simultaneous interactions outperform others. Other relevant theorists have identified how the lack of non-verbal indications provide communication difficulties sprung from functional limitations and intensive communication flows. This is creating implications for work productivity as Instant Messaging interrupt ongoing tasks, disrupt the turn-taking and complicates the conveyance of emotions. This thesis therefore aim to study how employees manage multicommunication and the communication difficulties that emerge in use of Instant Messaging.  A case study is conducted, by participant observations and semi-structured interviews, at a department of a multinational industrial company. The results show that the way employees manage multicommunication and communication difficulties is strongly bound to the context of use. In a mix of experiences and social rules a set of agreed strategies is used to help balance and control the communication flow and also reduce negative effects of functional limitations. To primarily communicate time-sensitive content the number of active interactions is reduced, unnecessary interruptions is avoided and a proper allocation of attention is facilitated. Mostly send messages also consists of print screens captured in the ERP-system which holds information in a formalized interface. The use of print screens is appreciated in favor of making the communication flow less intense by replacing an incredible number of messages. This usage facilitate the coordination of turn-taking, the possibility of instant feedback and the creation of content in not having to phrase in writing to convey emotions.

One would like to evaluate and compare complex digital communication systems based upon their overall bit error rate. Unfortunately, analytical expressions for bit error rate for even simple communication systems are notoriously difficult to evaluate accurately. Therefore, communication engineers often resort to simulation techniques to evaluate these error probabilities. In this thesis importance sampling techniques (variations of standard Monte Carlo methods) are studied in relation to both linear and non-linear detectors. Quick simulation, an importance sampling method based upon the asymptotics of the error estimator, is studied in detail. The simulated error probabilities are compared to values obtained by numerically inverting Laplace Transform expressions for these quantities.