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- Bilstrup, Urban, 1971-
(author)
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Design Space Exploration of Wireless Multihop Networks
- 2005
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Licentiate thesis (other academic/artistic)abstract
- This thesis explores the feasible design space of wireless multihop networks and identifies fundamental design parameters. In the process of exploring it is important to ignore all details and instead take a holistic view. This means that all protocol details are overseen, all details of radio wave propagation models are overseen and the system is modelled strictly on an architectural level. From a theoretical information perspective, there is a limit to the capacity that a certain bandwidth and a certain signal-to-noise ratio at the receiver can provide. This limit is approximated as a volume in the time-frequency-space domain. A single transmission is represented as an occupied volume in this domain. A wireless multihop network covers a spatial area, and the question is how multiple numbers of transmission volumes can be fit into a given limited spatial area. This volume fitting should be done in order to maximize the overall performance or to trade available resources to favour a specific characteristic in the wireless multihop network. The volume model is used for the design space exploration of a wireless multihop network. It is argued that the fault tolerance and the energy gain achieved in a multihop topology are its strength as compared to a single-hop architecture. It is further shown that the energy gain is achieved at the expense of delay and a greater end-to-end error probability. This indicates that these parameters must be very carefully balanced in order to gain in the global overall performance perspective. It can further be concluded that the overall spatial capacity is increased as a result of the spatial channel reuse in a multihop topology. On the other hand, it is also shown that the multihop topology introduces a rather stringent geometrical capacity limitation when the number of nodes of a wireless multihop network is increased. The dynamics (e.g. node mobility, changing radio channels etc.) of a large scale wireless multihop network is also a limiting factor. The nodes’ mobility creates a knowledge horizon beyond which very little can be known about the present network topology.
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| 3. |
- Johnsson, Dennis, et al.
(author)
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Analyzing the Advantages of Run-Time Reconfiguration in Radar Signal Processing
- 2005
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In: Proceedings of the 17th IASTED International Conference on Parallel and Distributed Computing and Systems. - Anaheim : ACTA Press. - 0889865256 - 9780889865259 ; , s. 701-706
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Conference paper (peer-reviewed)abstract
- Configurable architectures have emerged as one of the most powerful programmable signal processing platforms commercially available, obtaining their performance through the use of spatial parallelism. By changing the functionality of these devices during run-time, flexible mapping of signal processing applications can be made. The run-time flexibility puts requirements on the reconfiguration time that depend both on the application and on the mapping strategy. In this paper we analyze one such application, Space Time Adaptive Processing for radar signal processing, and show three different mappings and their requirements. The allowed time for run-time reconfiguration in these three cases varies from 1 ms down to 1 µs. Each has its own advantages, such as data reuse and optimization of computational kernels. Architectures with reconfiguration times in the order of 10 µs provide the flexibility needed for mapping the example in an efficient way, allowing for on-chip data reuse between the different processing stages.
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| 4. |
- Larsson, Tony, et al.
(author)
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T4 - Telematics for Totally Transparent Transports
- 2005
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In: 2005 IEEE Intelligent Transportation Systems Conference (ITSC). - New York : IEEE Press. - 0780392159 ; , s. 467-472
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Conference paper (peer-reviewed)abstract
- Transports can be made safer, more secure and efficient by help of telemetry and tracking on-line in real time. T4 is a system architecture aimed to support the development of telematic services for transparent tracking and surveillance monitoring of goods transported by different means on a global scale. The main idea is to focus on the transported pallets or parcels instead of the vehicles moving them. To enable rapid response to new customer requirements and to support remote management of field equipment, software implemented services are designed, packaged, deployed and mediated using XML, Java and the OSGi software technology standards.
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| 5. |
- Åhlander, Anders, et al.
(author)
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Meeting Engineer Efficiency Requirements in Highly Parallel Signal Processing by Using Platforms
- 2005
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In: Proceedings of the 17th IASTED International Conference on Parallel and Distributed Computing and Systems. - Anaheim : ACTA Press. - 0889865256 - 9780889865259 ; , s. 693-700
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Conference paper (pop. science, debate, etc.)abstract
- One of the driving forces behind the development of new, highly parallel architectures is the need for embedded high-performance computing. The development of advanced applications on such architectures is, however, potentially connected to high costs. Cost-effective devel opment requires tools and processes that provide engineer efficiency, in this case tools and processes that help the developer master the application complexity. Related to engineer efficiency are the important concepts of system sustainability and flexibility. To address these issues, a platform approach can be taken. The platform should offer an understandable and stable development model, and at the same time give the possibility to take advantage of the rapid technology development, including the use of new parallel architectures. Thus it must support multiple hard ware targets, and the development model should decouple application development from mapping aspects. Two radar signal processing examples, one compute-intensive STAP and one data-intensive SAR, are used to illustrate the need. The GEPARD platform is presented as an example of our approach, and we argue that the described platform is a good fit for advanced signal processing development, facilitating the desired engineer efficiency, sustainability, and flexibility.
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