In this thesis some different Modulation schemes for xDSL-techniques are compared. The investigated techniques are ADSL, G.lite, ADSL2, HDSL, SHDSL and VDSL. The Modulation methods used are DMT, CAP and different versions of PAM. Several broadband techniques also use Trellis Coded Modulation (TCM) to increase the coding gain of the transmission. For each one of the different Modulation methods the signal-to-noise ratio is calculated for generating a bit error rate probability of 10-7.

The aim of this project is to find a concept solution for a wireless transmitting system, installed to transmit data from a hydrophone of the ocean floor down by a wave power generator to the office on shore. The project is a literature review in which previous observations and tests are analyzed and put together to find a solution. The result was a comprehensive solution that includes an acoustic modem to transfer captured information from the bottom to the surface, wirelessly through the water. The information is then sent fron the surface on radio waves through the GSM network to the office on land. Between under and over water there are components to convert information between acoustic waves and radio waves, but also various types of Modulation, such as amplitude and frequency Modulation is required..

One of ABB Power Systems´s business areas is HVDC (High Voltage Direct Current) technology. HVDC is used for transmissions for both short and long distances. One of Power Systems?s products is called HVDC Light. HVDC Light is a relatively new technology for power transmission, but have before only been used for motor drives applications.

This report deals with the modeling of a part of the communication system based on the IEEE 802.11a standard which represents the next generation of wireless LAN with greater scalability, better interference immunity and significantly higher speed, up to 54 Mbps. 802.11a uses Orthogonal Frequency Division Multiplexing (OFDM) where Modulation is performed by an IFFT and the deModulation by an FFT. After modeling the FFT in Matlab and C, the FFT implementation has been validated using a soft microprocessor core by Xilinx (Microblaze) and the results were compared..

Australia is one of the largest producers and consumers of fossil fuels in the world. In a society where the effects of fossil fuels on global warming are constantly discussed, the nation?s production and consumption are subject to debate. Problems arise when negative aspects of consumption, such as emissions of greenhouse gases, are put in relation to an increased need of energy and economic growth. However, it is important to distinguish between different types of fossil fuels when it comes to their individual impact on the environment and to analyze the possibilities to increase the more environmental friendly ones.

Ternary codes for unequal error protection is a part of a communication system where different parts of the information to be transmitted can receive different amount of error protection. There are a lot of applications where the channel conditions fluctuate so that reliable or acceptable communication can not be guaranteed. Regardless whether the fluctuations of the channel are intentional or not the idea is to let the coderate decrease so that the error correcting capability can increase for the part of the information to be more protected. By using the support, the nonzero positions of the ternary code, a new binary code can be extracted with properties different from the ternary code in the sense of cardinality and minimum Hamming distance. When the channel conditions are good the receiver decodes the message using ternary decisions and receives all information included in the codeword.

 I detta examensarbete har metoder för design av en FPGA-baserad PCM-till-PWM-modulator för klass D-audioförstärkare testats och utvärderats. Rapporten diskuterar med stöd av matematisk analys och simuleringar interpoleringsmetoder, pulsbreddsmodulering, samplingsprocesser och sigma-delta-modulatorer. Den föreslagna designen bygger på uppsampling, förkompensering, brusformning och pulsbreddsmodulering. Designens prestanda har verifierats genom simulering av modell och implementering i hårdvara. .

At the Department of Technology and Built environment at the University of Gävle there was an interest to study GNU Radio, which is an "open source radio project. The project is based on that most of the radio signal processing is made in an ordinary PC. The idea behind this degree project was that in a laptop there are several radio transmitters/receivers that takes space, generates heat and transmit in varied frequency band etcetera. All these radio transmitters/receivers could be replaced with a Software Defined Radio system. It means that one common, general radio hardware is used to different communications such as: WLAN, Bluetooth, GPRS, 3G etcetera. The waveform is generated in the software, which makes the system very flexible.

Speech Transmission Index (STI) är både en metod för att mäta taltydlighet och en skala som beskriver taltydlighet. Metoden presenterades av H. Steeneken och T. Houtgast 1985 och har därefter fått många användningsområden. STI beräknas utifrån Modulationsindex, där Modulationsindex är förändringen av Modulation genom ett system.

Speech Transmission Index (STI) är både en metod för att mäta taltydlighet och en skala som beskriver taltydlighet. Metoden presenterades av H. Steeneken och T. Houtgast 1985 och har därefter fått många användningsområden. STI beräknas utifrån Modulationsindex, där Modulationsindex är förändringen av Modulation genom ett system.

I sjukvården världen över tas dagligen tusentals röntgenbilder. Användningsområdena är många, men i de flesta fall är syftet att i något avseende avgöra patientens hälsa. Bilderna utvärderas av läkare för att patienten ska få rätt diagnos. För att läkaren ska kunna göra en korrekt bedömning av bilden och därmed ge patienten den behandling som situationen kräver måste bilden vara rättvisande och vara av sådan kvalitet att alla viktiga detaljer går att urskilja. Bildkvalitet är ett ganska diffust begrepp och ofta används subjektiva bedömningsmetoder för att bestämma ifall en bild är bra eller dålig.

The purpose of this degree project was to build laboratory equipment for a new course in power electronics that starts this autumn 2010 at Uppsala University. The equipment is intended for student labs and it covers the most important areas of the course including rectifying, buck-/boost-converters and PWM-Modulation. It is built as one sealed unit where all the electronics are built-in but visible and it has a connection board where students safely can connect the different circuits. The project has advanced from theoretical studies of circuit design, choosing of components and simulations to drawing the printed circuit board (PCB), soldering, case building, final testing and troubleshooting - basically most steps from an early idea to a final product. Measurements on the final product gave about the same results as the earlier simulations of the circuits and the result is overall satisfying..

This thesis investigates techniques for stealth hydroacoustic communication using spread spectrum. The Swedish naval defense organisations have a vision that all their units should be able to communicate with each other, even between underwater vehicles. But the properties of water makes it a complex channel to use for wireless communications. Radiomagnetic waves have very limited range in water, therefore acoustic waves are used. In this report the basics of wireless communication systems are described including source coding, channel coding, Modulation techniques as well as different techniques for spread spectrum.

The cause of fibromyalgia has long been unknown but recent studies has shown that disturbance in the central pain Modulation may be the cause. The aim of the study was to examine what kind of physiotherapy and close related treatment methods in the treatment of fibromyalgia there are and to determine their evidence. Articles were obtained by searching through the databases PubMed, Academic Search, AMED/Webspirs, CINAHL/webspirs and PEDro for articles published from 1994 and ten years forward. The study was based on thirty articles that met the criteria for inclusion. To assess the quality of the clinical studies the SBU?s evaluation model was used.

EN BILD SÄGER MER ÄN TUSEN ORD? Idag finns det gott om studier som behandlar området digital kommunikation. Det är ett omfattande ämne och det har forskats mycket inom det. Det finns massvis med litteratur och vetenskapliga artiklar som beskriver olika digitala kommunikationstekniker. Studeras dessa inses det ganska fort att de håller en hög och komplex nivå.