<p>Abstract</p><p>The rapid development within the field of measurement methods and techniques and software design that has taken place over the last years offers new possibilities for designers of measurement systems through the use of virtual instruments as building blocks. The concept of virtual instrumentation is developed within the interchangeable virtual instrument foundation. A closely related term is “synthetic instruments”, which is often used for essentially the same concept, but it is even more software oriented. Synthetic instruments as a research field are in an initial stage and a quick search on “Synthetic instruments” in Institute of Electrical and Electronics Engineers (IEEE) explorer match close to 30 documents. IEEE explorer is a database that provides full-text access to IEEE transactions, journals, magazines and conference proceedings, and all current IEEE Standards.</p><p>This Master Thesis is a theoretical work extracted from study material, IEEE documents and web-resources referenced. The work gives the reader an overview of the Synthetic Instruments and their functionality with respect to hardware and software. The papers were analyzed based upon the various trends in the research, development and productizing phases.</p><p>For this approach; kernel architecture of an ideal synthetic instrument has been introduced as a prototype around which current technologies and applications can be addressed. The major areas of focus in the architecture are the data conversion and signal conditioning; the knowledge of its working under current implemented technologies has been highlighted and discussed in regards to the software and hardware trends. The defense industry holds the major influence.</p><p>The work was aimed towards giving a state-of-the art introduction to synthetic instrument technology; also in order to provide the work an introductory nature, only one hardware & software example has been discussed.</p>

<p>Sammanfattning</p><p>Denna rapport beskriver ett examensarbete som gjordes åt TietoEnator. Målet med examensarbetet var att optimera listhantering i en telekomapplikation. För att utföra detta användes programmeringsspråket C. Uppgiften omfattade fyra delar som bestod av att:</p><p>- Undersöka den nuvarande implementationen</p><p>- Föreslå förbättring till den nuvarande implementationen</p><p>- Implementera den utvalda lösningen</p><p>- Utföra mätningar samt dokumentera resultaten</p><p>Undersökningen av den nuvarande implementationen gjordes genom flera olika mätningar för att kunna se exekveringstiderna på operationerna. Förslag till förbättringar till den nuvarande implementationen gjordes genom analysering av olika datastrukturer. Implementationen av den utvalda lösningen blev ett AVL-träd och en hjälplista som är en länkad lista. Mätningar och dokumentation gjordes genom att mäta tider på den gamla och nya implementationen där man sedan jämförde exekveringstiderna. Resultatet blev en klar förbättring som t.ex. sökning av ett objekt vilket blev i snitt 3000 ggr snabbare. Det vi har gjort i detta examensarbete kommer TietoEnator att implementera och utveckla vidare.</p>

Abstract The rapid development within the field of measurement methods and techniques and software design that has taken place over the last years offers new possibilities for designers of measurement systems through the use of virtual instruments as building blocks. The concept of virtual instrumentation is developed within the interchangeable virtual instrument foundation. A closely related term is “synthetic instruments”, which is often used for essentially the same concept, but it is even more software oriented. Synthetic instruments as a research field are in an initial stage and a quick search on “Synthetic instruments” in Institute of Electrical and Electronics Engineers (IEEE) explorer match close to 30 documents. IEEE explorer is a database that provides full-text access to IEEE transactions, journals, magazines and conference proceedings, and all current IEEE Standards. This Master Thesis is a theoretical work extracted from study material, IEEE documents and web-resources referenced. The work gives the reader an overview of the Synthetic Instruments and their functionality with respect to hardware and software. The papers were analyzed based upon the various trends in the research, development and productizing phases. For this approach; kernel architecture of an ideal synthetic instrument has been introduced as a prototype around which current technologies and applications can be addressed. The major areas of focus in the architecture are the data conversion and signal conditioning; the knowledge of its working under current implemented technologies has been highlighted and discussed in regards to the software and hardware trends. The defense industry holds the major influence. The work was aimed towards giving a state-of-the art introduction to synthetic instrument technology; also in order to provide the work an introductory nature, only one hardware &amp; software example has been discussed.

This thesis examines the possibility of installing a wireless communication system based on multiple antennas, on an Unmanned Aerial Vehicle (UAV). The communication system is based on MIMO technology. This technology uses the fact that we can make use of several antennas at the transmitter and the receiver to create independent signal path which in turn can increase the roboustness of the communication link. Advantages and disadvantages of this new system arediscussed. However, this report concludes that the benefits of MIMO outweights the disadvantages. Furthermore a simulation environment for the MIMO system is designed and implemented, based on a specific scenario. Moreover, the results from the simulation also points to a benefit of the MIMO technology.

Quality of Service is a set of mechanisms created for differentiating users and data flows. Provisioning the QoS in service provider networks is always interesting for their business departments for they can offer and sell diverse services and to make more money. This thesis QoS for DSL subscribers of Pardis Online - the private ISP in Iran. The size of the network, the certain network connectivity limitations the ISP has in addition to the complexity of the services it provides, necessitate a comprehensive study to elucidate the different service types and requirements and then choosing a specific implementation of QoS in order to meet the ISP’s need. The internet bandwidth in the region that ISP operates is very expensive and the users suffer from the lack of bandwidth so the limited internet links are usually congested in the network. This document concludes with proposing a layered QoS that guarantees that the total bandwidth of an area in congested times is distributed to the users in that area proportionate to the subscribed band width. The resulting proposals are tested in the Lab and their performance under the simulated traffic is monitored and analyzed.

<p>Future wireless communication systems will utilize the spatial properties of the wireless channel to improve the spectral efficiency and thus increase capacity. This is realized by deploying multiple antennas at both the transmitter and receiver. Utilizing the spatial properties of the channel demands channel models that properly reflect these characteristics. Due to the unpredictable nature of the wireless channel, a common approach is to model its effects in a statistical fashion. A few large world wide cooperations, like the 3GPP or WINNER projects, have developed channel models intended for reference and standardization use. These models are partly based on bulk parameters which describe the characteristics of the channel over larger areas of several wavelengths. These parameters include shadow fading, angle spread, and delay spread among others, and are within the WINNER project called large scale (LS) parameters. Considering the variations of these parameters, it is likely that they are correlated between closely located areas. Therefore it is of key interest to model their correlation properties instead of randomizing them independently for each new simulation. In multi-cell scenarios, when considering macro diversity or evaluation other properties such as interference and/or handover schemes, the intra site correlation of the shadow fading parameters should be taken into account for proper simulations. Neglecting this correlation the interference could be over/under estimated, hence the system capacity can be over/under estimated. Further, reliable estimations of the interference levels will increase the frequency reuse, and may even permit reuse within the same cell, on spatially separated links. The thesis focuses on modelling the statistics and variations of these parameters to increase accuracy of channel models. Previous studies have looked at the autocorrelation properties of the shadow fading in outdoor environments and found it to follow an exponential decay. This means that an first order autoregressive function would be sufficient to model this effect. Research of the angular spread parameter is more scarce, and therefor this issue is studied herein. In addition to the autocorrelation properties the intra-site correlation between the different large scale parameters is of interest. It is herein found that the shadow fading is negatively correlated with angle spreads, while the angle spread at the base station and the angle spread at the mobile show positive correlation. Finally, the inter site correlation between one mobile and multiple base stations is studied as a function of the angular separation between the links. For closely located base station, ie with small angular separation as seen from the mobile, substantial inter-site correlation is found. It is further seen that the correlation of the shadow fading is more prominent than the correlation of angle spread.</p>

Zugl.: Augsburg, Universiẗat, Diss., 2009.

The up growing wireless communication field always need such a system which is simple but more reliable for multiple applications. To fulfill these demands the modern receiver RF frontend can play an important role. A successful design could be a better solution, not only simple but also modern receiver architecture topology is necessary.The main objective of this dissertation is to design a simple RF-Front end for both multi-band multi-systems Global Navigation Satellite System (GNSS i.e. GPS and Galileo) receiver which will provide civil signals on multiple frequencies, similar to those currently available for only military purpose and finally implement and test the receiver front end. Different topologies have been investigated and finally the direct digitization RF front end receiver topology is chosen for simplicity, cost and performance. The entire RF front receiver consists of a broad band LNA, a broad band pass filter and a band stop filter. This kind of receiver needs a minimum feasible sampling frequency which is 434 MHz for designed methodology.A simple receiver RF front end for GNSS application is designed to demonstrate and it has been implemented and tested. The receiver is yield the minimum power consumption which is 26mA current from 3V power supply.Although, there are no such a specifications for combined future GPS/Galileo receiver, the simple design performance is satisfactory and it will be an interesting future work from commercial point of view.

Universiẗat, Diss., 2007--Sankt Gallen. / Hergestellt on demand.

Diss. Linköping : Univ., 1998.