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280 Uppsatser om Rayleigh fading channel - Sida 1 av 19

Utvärdering av försvarsspecifika radiovågformer

To be able to evaluate different radio waveforms in a laboratory environment FOI in Linköping has developed an experimental system for radio communication called Rasmus. The system consists of a transmitter, a channel emulator and a receiver. The transmitter modulates a digital signal to a desired analogue waveform. The channel emulator is used to simulate a real radio channel. The channel emulator distorts the signal by splitting it up in several propagation paths.

MIMO kanalmodeler

The objective of this diploma work is to investigate a set of Multiple Input Multiple Output (MIMO) channel models compatible with the emerging IEEE 802.11n standard. This diploma work validates also advanced, innovative tools and wireless technologies that are necessary to facilitate wireless applications while maximizing spectral efficiency and throughput. MIMO channel models can be used to evaluate new Wireless Local Area Network (WLAN) proposals based on multiple antenna technologies. The purpose of this thesis is to investigate means of channel models and their implementation in different environments such as: Matlab, C++ and Advanced Design Systems (ADS). The investigation considers also a comparison between the channel models based on theoretical data and parameter setup to the channel models based on statistical characteristics obtained from measured data.

Modelering av Wideband : Code Division Multiple Access

Today wireless transmission of data is becoming more and more popular and the need for faster transmission rates is increasing. Since the bandwidth is limited it is important to try to use it to the fullest. CDMA is a technology that allows multiple accesses on the same frequency and time thus making it very bandwidth efficient. The CDMA technology was first introduced in the second generation?s cellular systems but has since then been improved and is reused in today?s 3G systems as Wideband CDMA.

Rayleigh-Bénard konvektion.

AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.

Provisionsbaserad lön och prisskillnader mellan kanaler ? en källa till kanalkonflikter? : En fallstudie bland företag i Sundsvall

Today?s companies offer their products and services through multiple distribution channels in an increasing extent, in order to reach bigger markets and more customers. Multiple channels result in an increased risk for channel conflict.This essay is an exploratory and descriptive study with the purpose to explore some companies? channel conflicts on the basis of sales commission and price differences. A case study has been made at two different companies and the empirical material has been collected with qualitative interviews.We found more channel conflicts in the company that uses sales commissions than in the company that doesn?t.

Jämförelse mellan MultiScat och konventionell beräkning av intensiteter till koncentrationer vid analys med röntgenflourescensspektrometri

In this master thesis work, a new method called MultiScat, is compared with the conventional method with alfa-correction, for computing concentrations from intensities in X-ray spectrometric analysis. The conventional model is a linear model, which only takes the photoelectric effect into consideration. It doesn't consider Rayleigh and Compton scattering even though it has a great impact on the measured intensities. Here MultiScat differs a lot. MultiScat is based on a solution of the Boltzmann transport equation.

Betydelsen av att välja En kvantitativ studie om olika distributionskanaler för enkätundersökningar

No other object is in our constant possession such as the mobile phone. The smartphone has been transformed into a worldwide forum for information-rich exchanges between individuals and companies, by which this rapid access to the smartphone has created and continues to create opportunities in terms of communication. Many researchers of today undertake the challenge of studying the smartphone's role as a marketing channel, and the role of the channel is now undoubtedly central in marketing. However, as the importance of marketing communication increases and despite the fact that survey methods are exceedingly dependent on a channel to fulfill its purpose, namely carry out questionnaires, there has been surprisingly little attention to the study of the channel's role and importance when carrying out surveys. The main purpose of this paper is to investigate whether the choice of a communication channel affects the survey outcome and, if so, further investigate how survey methods differ in terms of consumers' attitude and also their perception of their privacy.

Music Television : en TV-kanals förändring i ett nytt medieklimat

Purpose/Aim: The purpose of this essay is to analyze and discuss how MTV is affected by the development that takes place on the world?s media market. The aim is also to see how MTV?s target group?s image of the channel can give guidelines in how MTV should act in this new media era.Material/method: I have examined the development on the media market and then created a model consisting of relevant factors that could affect a TV-channel today. Those factors and the two factors image and profile are then applied on MTV.

Flerkanalspublicering och dess påverkan på journalisters arbetssituation : en studie av flerkanalspublicering i olika stadier

Purpose/Aim: The aim of this thesis was to examine how multi channel publishing in different stages effect the work for journalists.Material/Method: The thesis is based on ten case studies selected from the literature and one conducted especially for this thesis. The case studies have been categorized according to a model that describes three strategies for multi channel publishing. The first strategy is to have a primary publishing channel, the second is to have separate editorial staffs for all publishing channels and the third is to treat all publishing channels equally.Main results: Journalists working for companies using the first strategy have not experienced any major differences in working conditions or work practices. For journalists employed by companies using the second strategy for multi channel publishing the effects on the journalists was noticeable but not major. The effects on journalists in companies using the third strategy are mainly stress and an uncertainty regarding how to use special media techniques..

Höghastighetståg - Är det framtiden?

AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.

Internet : som kompletterande kommunikationskanal till Event Marketing

The aim of this essay is to examine how the Internet functions as a communication channel to Event Marketing. We have investigated what makes the Internet unique as a communication channel for events and how Internet has been used for event marketing. We have mapped fundamental theories within marketing, media, communications and human-computer interaction, which together describe event marketing. We have carried out case studies on two event-marketing projects where the Internet has played a major role. The first project was XCT which is a project developed by the company Eventum AB.

E-tjänstutveckling ur ett medborgarperspektiv : Att skapa beslutsunderlag baserat på medborgarärendens lämplighet för olika kommunikationskanaler

Citizens? interaction with governments is an area with unique implications for channel management. Governments need to take the citizens perspective into further consideration in order to be successful in delivering high-quality e-services. This paper aims to determine if a categorization of citizen-initiated contacts from a citizen-centric perspective can be a valuable basis for decisions regarding e-service development. The study consisted of three steps.

Utvärdering av en beslutsåterkopplad kanalestimator för tredje generationens mobiltelefonisystem

This Masters thesis work describes a comparison between two different methods for estimation of the down channel (base station to mobile subscriber) in Wide-band Code Division Multiple Access (WCDMA). The first estimation method, Optimal Feed-forward Channel Estimation (OFCE), is a conventional method that bases the estimates on data that is known to both sender and receiver, so called pilots. The second method, Decision Directed Channel Estimation (DDCE), is an elaboration of OFCE. It also uses user data for estimation. Simulations show that DDCE, in comparison to OFCE, does not attain an improvement in signal-to-noise-ratio (SNR) for high bit error rates (BER).

Utvärdering av en beslutsåterkopplad kanalestimator för tredje generationens mobiltelefonisystem

This Masters thesis work describes a comparison between two different methods for estimation of the down channel (base station to mobile subscriber) in Wide-band Code Division Multiple Access (WCDMA). The first estimation method, Optimal Feed-forward Channel Estimation (OFCE), is a conventional method that bases the estimates on data that is known to both sender and receiver, so called pilots. The second method, Decision Directed Channel Estimation (DDCE), is an elaboration of OFCE. It also uses user data for estimation. Simulations show that DDCE, in comparison to OFCE, does not attain an improvement in signal-to-noise-ratio (SNR) for high bit error rates (BER). An improvement is only seen when the BER becomes much lower than what is common in real situations. In conclusion DDCE is complicated, involves many mathematical operations and gives insignificant improvement of SNR when BER takes common values. It is legitimate to question if it is possible to use the method in a real mobile phone system..

Mannen med makt och den omhändertagande kvinnan : En studie om genusrepresentation i debattprogram i TV4 och SVT

We have studied the differences between people debating on a program in apublic service-channel and a privately-owned channel. We have chosen thetwo biggest debate programs, Kvällsöppet in the privately-owned channelTV4 and Debatt in the public service-channel SVT 1. We have in aquantitative content analysis studied female and male, how many of each thatare participating, how long time they talk in the program and in what rolethey have in the debate. We have studied 10 episodes of Kvällsöppet thespring season 2010 and compared with Johanna Paulsson & Patrik Rosellstudy ?30/70.

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